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http://rosettacode.org/wiki/Van_der_Corput_sequence | Van der Corput sequence | When counting integers in binary, if you put a (binary) point to the righEasyLangt of the count then the column immediately to the left denotes a digit with a multiplier of
2
0
{\displaystyle 2^{0}}
; the digit in the next column to the left has a multiplier of
2
1
{\displaystyle 2^{1}}
; and so on.
So in the following table:
0.
1.
10.
11.
...
the binary number "10" is
1
×
2
1
+
0
×
2
0
{\displaystyle 1\times 2^{1}+0\times 2^{0}}
.
You can also have binary digits to the right of the “point”, just as in the decimal number system. In that case, the digit in the place immediately to the right of the point has a weight of
2
−
1
{\displaystyle 2^{-1}}
, or
1
/
2
{\displaystyle 1/2}
.
The weight for the second column to the right of the point is
2
−
2
{\displaystyle 2^{-2}}
or
1
/
4
{\displaystyle 1/4}
. And so on.
If you take the integer binary count of the first table, and reflect the digits about the binary point, you end up with the van der Corput sequence of numbers in base 2.
.0
.1
.01
.11
...
The third member of the sequence, binary 0.01, is therefore
0
×
2
−
1
+
1
×
2
−
2
{\displaystyle 0\times 2^{-1}+1\times 2^{-2}}
or
1
/
4
{\displaystyle 1/4}
.
Distribution of 2500 points each: Van der Corput (top) vs pseudorandom
0
≤
x
<
1
{\displaystyle 0\leq x<1}
Monte Carlo simulations
This sequence is also a superset of the numbers representable by the "fraction" field of an old IEEE floating point standard. In that standard, the "fraction" field represented the fractional part of a binary number beginning with "1." e.g. 1.101001101.
Hint
A hint at a way to generate members of the sequence is to modify a routine used to change the base of an integer:
>>> def base10change(n, base):
digits = []
while n:
n,remainder = divmod(n, base)
digits.insert(0, remainder)
return digits
>>> base10change(11, 2)
[1, 0, 1, 1]
the above showing that 11 in decimal is
1
×
2
3
+
0
×
2
2
+
1
×
2
1
+
1
×
2
0
{\displaystyle 1\times 2^{3}+0\times 2^{2}+1\times 2^{1}+1\times 2^{0}}
.
Reflected this would become .1101 or
1
×
2
−
1
+
1
×
2
−
2
+
0
×
2
−
3
+
1
×
2
−
4
{\displaystyle 1\times 2^{-1}+1\times 2^{-2}+0\times 2^{-3}+1\times 2^{-4}}
Task description
Create a function/method/routine that given n, generates the n'th term of the van der Corput sequence in base 2.
Use the function to compute and display the first ten members of the sequence. (The first member of the sequence is for n=0).
As a stretch goal/extra credit, compute and show members of the sequence for bases other than 2.
See also
The Basic Low Discrepancy Sequences
Non-decimal radices/Convert
Van der Corput sequence
| #REXX | REXX | /*REXX program converts an integer (or a range) ──► a Van der Corput number in base 2.*/
numeric digits 1000 /*handle almost anything the user wants*/
parse arg a b . /*obtain the optional arguments from CL*/
if a=='' then parse value 0 10 with a b /*Not specified? Then use the defaults*/
if b=='' then b= a /*assume a range for a single number.*/
do j=a to b /*traipse through the range of numbers.*/
_= VdC( abs(j) ) /*convert absolute value of an integer.*/
leading= substr('-', 2 + sign(j) ) /*if needed, elide the leading sign. */
say leading || _ /*show number, with leading minus sign?*/
end /*j*/
exit /*stick a fork in it, we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
VdC: procedure; y= x2b( d2x( arg(1) ) ) + 0 /*convert to hexadecimal, then binary.*/
if y==0 then return 0 /*handle the special case of zero. */
return '.'reverse(y) /*heavy lifting is performed by REXX. */ |
http://rosettacode.org/wiki/URL_decoding | URL decoding | This task (the reverse of URL encoding and distinct from URL parser) is to provide a function
or mechanism to convert an URL-encoded string into its original unencoded form.
Test cases
The encoded string "http%3A%2F%2Ffoo%20bar%2F" should be reverted to the unencoded form "http://foo bar/".
The encoded string "google.com/search?q=%60Abdu%27l-Bah%C3%A1" should revert to the unencoded form "google.com/search?q=`Abdu'l-Bahá".
| #M2000_Interpreter | M2000 Interpreter |
Module CheckIt {
Function decodeUrl$(a$) {
DIM a$()
a$()=Piece$(a$, "%")
if len(a$())=1 then =str$(a$):exit
k=each(a$(),2)
\\ convert to one byte per character using str$(string)
acc$=str$(a$(0))
While k {
\\ chr$() convert to UTF16LE
\\ str$() convert to ANSI using locale (can be 1033 we can set it before as Locale 1033)
\\ so chr$(0x93) give 0x201C
\\ str$(chr$(0x93)) return one byte 93 in ANSI as string of one byte length
\\ numbers are for UTF-8 so we have to preserve them
acc$+=str$(Chr$(Eval("0x"+left$(a$(k^),2)))+Mid$(a$(k^),3))
}
=acc$
}
\\ decode from utf8
final$=DecodeUrl$("google.com/search?q=%60Abdu%27l-Bah%C3%A1")
Print string$(final$ as utf8dec)="google.com/search?q=`Abdu'l-Bahá"
final$=DecodeUrl$("http%3A%2F%2Ffoo%20bar%2F")
Print string$(final$ as utf8dec)="http://foo bar/"
}
CheckIt
|
http://rosettacode.org/wiki/URL_decoding | URL decoding | This task (the reverse of URL encoding and distinct from URL parser) is to provide a function
or mechanism to convert an URL-encoded string into its original unencoded form.
Test cases
The encoded string "http%3A%2F%2Ffoo%20bar%2F" should be reverted to the unencoded form "http://foo bar/".
The encoded string "google.com/search?q=%60Abdu%27l-Bah%C3%A1" should revert to the unencoded form "google.com/search?q=`Abdu'l-Bahá".
| #Maple | Maple | StringTools:-Decode("http%3A%2F%2Ffoo%20bar%2F", encoding=percent); |
http://rosettacode.org/wiki/UPC | UPC | Goal
Convert UPC bar codes to decimal.
Specifically:
The UPC standard is actually a collection of standards -- physical standards, data format standards, product reference standards...
Here, in this task, we will focus on some of the data format standards, with an imaginary physical+electrical implementation which converts physical UPC bar codes to ASCII (with spaces and # characters representing the presence or absence of ink).
Sample input
Below, we have a representation of ten different UPC-A bar codes read by our imaginary bar code reader:
# # # ## # ## # ## ### ## ### ## #### # # # ## ## # # ## ## ### # ## ## ### # # #
# # # ## ## # #### # # ## # ## # ## # # # ### # ### ## ## ### # # ### ### # # #
# # # # # ### # # # # # # # # # # ## # ## # ## # ## # # #### ### ## # #
# # ## ## ## ## # # # # ### # ## ## # # # ## ## # ### ## ## # # #### ## # # #
# # ### ## # ## ## ### ## # ## # # ## # # ### # ## ## # # ### # ## ## # # #
# # # # ## ## # # # # ## ## # # # # # #### # ## # #### #### # # ## # #### # #
# # # ## ## # # ## ## # ### ## ## # # # # # # # # ### # # ### # # # # #
# # # # ## ## # # ## ## ### # # # # # ### ## ## ### ## ### ### ## # ## ### ## # #
# # ### ## ## # # #### # ## # #### # #### # # # # # ### # # ### # # # ### # # #
# # # #### ## # #### # # ## ## ### #### # # # # ### # ### ### # # ### # # # ### # #
Some of these were entered upside down, and one entry has a timing error.
Task
Implement code to find the corresponding decimal representation of each, rejecting the error.
Extra credit for handling the rows entered upside down (the other option is to reject them).
Notes
Each digit is represented by 7 bits:
0: 0 0 0 1 1 0 1
1: 0 0 1 1 0 0 1
2: 0 0 1 0 0 1 1
3: 0 1 1 1 1 0 1
4: 0 1 0 0 0 1 1
5: 0 1 1 0 0 0 1
6: 0 1 0 1 1 1 1
7: 0 1 1 1 0 1 1
8: 0 1 1 0 1 1 1
9: 0 0 0 1 0 1 1
On the left hand side of the bar code a space represents a 0 and a # represents a 1.
On the right hand side of the bar code, a # represents a 0 and a space represents a 1
Alternatively (for the above): spaces always represent zeros and # characters always represent ones, but the representation is logically negated -- 1s and 0s are flipped -- on the right hand side of the bar code.
The UPC-A bar code structure
It begins with at least 9 spaces (which our imaginary bar code reader unfortunately doesn't always reproduce properly),
then has a # # sequence marking the start of the sequence,
then has the six "left hand" digits,
then has a # # sequence in the middle,
then has the six "right hand digits",
then has another # # (end sequence), and finally,
then ends with nine trailing spaces (which might be eaten by wiki edits, and in any event, were not quite captured correctly by our imaginary bar code reader).
Finally, the last digit is a checksum digit which may be used to help detect errors.
Verification
Multiply each digit in the represented 12 digit sequence by the corresponding number in (3,1,3,1,3,1,3,1,3,1,3,1) and add the products.
The sum (mod 10) must be 0 (must have a zero as its last digit) if the UPC number has been read correctly.
| #Nim | Nim | import algorithm, sequtils, strutils
const
LeftDigits = [" ## #",
" ## #",
" # ##",
" #### #",
" # ##",
" ## #",
" # ####",
" ### ##",
" ## ###",
" # ##"]
RightDigits = LeftDigits.mapIt(it.multiReplace(("#", " "), (" ", "#")))
EndSentinel = "# #"
MidSentinel = " # # "
template isEven(n: int): bool = (n and 1) == 0
proc decodeUPC(input: string) =
#.................................................................................................
proc decode(candidate: string): tuple[valid: bool, list: seq[int]] =
const Invalid = (false, @[])
var pos = 0
var next = pos + EndSentinel.len
if candidate[pos..<next] == EndSentinel:
pos = next
else:
return Invalid
for _ in 1..6:
next = pos + 7
let i = LeftDigits.find(candidate[pos..<next])
if i >= 0:
result.list.add i
pos = next
else:
return Invalid
next = pos + MidSentinel.len
if candidate[pos..<next] == MidSentinel:
pos = next
else:
return Invalid
for _ in 1..6:
next = pos + 7
let i = RightDigits.find(candidate[pos..<next])
if i >= 0:
result.list.add i
pos = next
else:
return Invalid
next = pos + EndSentinel.len
if candidate[pos..<next] == EndSentinel:
pos = next
else:
return Invalid
var sum = 0
for i, v in result.list:
sum += (if i.isEven: 3 * v else: v)
result.valid = sum mod 10 == 0
#.................................................................................................
var candidate = input.strip()
let output = candidate.decode()
if output.valid:
echo output.list.join(", ")
else:
candidate.reverse()
let output = candidate.decode()
if output.valid:
echo output.list.join(", "), " Upside down"
elif output.list.len == 0:
echo "Invalid digit(s)"
else:
echo "Invalid checksum: ", output.list.join(", ")
#———————————————————————————————————————————————————————————————————————————————————————————————————
when isMainModule:
const BarCodes = [
" # # # ## # ## # ## ### ## ### ## #### # # # ## ## # # ## ## ### # ## ## ### # # # ",
" # # # ## ## # #### # # ## # ## # ## # # # ### # ### ## ## ### # # ### ### # # # ",
" # # # # # ### # # # # # # # # # # ## # ## # ## # ## # # #### ### ## # # ",
" # # ## ## ## ## # # # # ### # ## ## # # # ## ## # ### ## ## # # #### ## # # # ",
" # # ### ## # ## ## ### ## # ## # # ## # # ### # ## ## # # ### # ## ## # # # ",
" # # # # ## ## # # # # ## ## # # # # # #### # ## # #### #### # # ## # #### # # ",
" # # # ## ## # # ## ## # ### ## ## # # # # # # # # ### # # ### # # # # # ",
" # # # # ## ## # # ## ## ### # # # # # ### ## ## ### ## ### ### ## # ## ### ## # # ",
" # # ### ## ## # # #### # ## # #### # #### # # # # # ### # # ### # # # ### # # # ",
" # # # #### ## # #### # # ## ## ### #### # # # # ### # ### ### # # ### # # # ### # # ",
]
for barcode in BarCodes:
barcode.decodeUPC() |
http://rosettacode.org/wiki/Update_a_configuration_file | Update a configuration file | We have a configuration file as follows:
# This is a configuration file in standard configuration file format
#
# Lines begininning with a hash or a semicolon are ignored by the application
# program. Blank lines are also ignored by the application program.
# The first word on each non comment line is the configuration option.
# Remaining words or numbers on the line are configuration parameter
# data fields.
# Note that configuration option names are not case sensitive. However,
# configuration parameter data is case sensitive and the lettercase must
# be preserved.
# This is a favourite fruit
FAVOURITEFRUIT banana
# This is a boolean that should be set
NEEDSPEELING
# This boolean is commented out
; SEEDSREMOVED
# How many bananas we have
NUMBEROFBANANAS 48
The task is to manipulate the configuration file as follows:
Disable the needspeeling option (using a semicolon prefix)
Enable the seedsremoved option by removing the semicolon and any leading whitespace
Change the numberofbananas parameter to 1024
Enable (or create if it does not exist in the file) a parameter for numberofstrawberries with a value of 62000
Note that configuration option names are not case sensitive. This means that changes should be effected, regardless of the case.
Options should always be disabled by prefixing them with a semicolon.
Lines beginning with hash symbols should not be manipulated and left unchanged in the revised file.
If a configuration option does not exist within the file (in either enabled or disabled form), it should be added during this update. Duplicate configuration option names in the file should be removed, leaving just the first entry.
For the purpose of this task, the revised file should contain appropriate entries, whether enabled or not for needspeeling,seedsremoved,numberofbananas and numberofstrawberries.)
The update should rewrite configuration option names in capital letters. However lines beginning with hashes and any parameter data must not be altered (eg the banana for favourite fruit must not become capitalized). The update process should also replace double semicolon prefixes with just a single semicolon (unless it is uncommenting the option, in which case it should remove all leading semicolons).
Any lines beginning with a semicolon or groups of semicolons, but no following option should be removed, as should any leading or trailing whitespace on the lines. Whitespace between the option and parameters should consist only of a single
space, and any non-ASCII extended characters, tabs characters, or control codes
(other than end of line markers), should also be removed.
Related tasks
Read a configuration file
| #Racket | Racket |
#lang racket
(require "options.rkt")
(read-options "options-file")
(define-options needspeeling seedsremoved numberofbananas numberofstrawberries)
;; Disable the needspeeling option (using a semicolon prefix)
(set! needspeeling #f)
;; Enable the seedsremoved option by removing the semicolon and any
;; leading whitespace
(set! seedsremoved ENABLE)
;; Change the numberofbananas parameter to 1024
(set! numberofbananas 1024)
;; Enable (or create if it does not exist in the file) a parameter for
;; numberofstrawberries with a value of 62000
(set! numberofstrawberries 62000)
|
http://rosettacode.org/wiki/Update_a_configuration_file | Update a configuration file | We have a configuration file as follows:
# This is a configuration file in standard configuration file format
#
# Lines begininning with a hash or a semicolon are ignored by the application
# program. Blank lines are also ignored by the application program.
# The first word on each non comment line is the configuration option.
# Remaining words or numbers on the line are configuration parameter
# data fields.
# Note that configuration option names are not case sensitive. However,
# configuration parameter data is case sensitive and the lettercase must
# be preserved.
# This is a favourite fruit
FAVOURITEFRUIT banana
# This is a boolean that should be set
NEEDSPEELING
# This boolean is commented out
; SEEDSREMOVED
# How many bananas we have
NUMBEROFBANANAS 48
The task is to manipulate the configuration file as follows:
Disable the needspeeling option (using a semicolon prefix)
Enable the seedsremoved option by removing the semicolon and any leading whitespace
Change the numberofbananas parameter to 1024
Enable (or create if it does not exist in the file) a parameter for numberofstrawberries with a value of 62000
Note that configuration option names are not case sensitive. This means that changes should be effected, regardless of the case.
Options should always be disabled by prefixing them with a semicolon.
Lines beginning with hash symbols should not be manipulated and left unchanged in the revised file.
If a configuration option does not exist within the file (in either enabled or disabled form), it should be added during this update. Duplicate configuration option names in the file should be removed, leaving just the first entry.
For the purpose of this task, the revised file should contain appropriate entries, whether enabled or not for needspeeling,seedsremoved,numberofbananas and numberofstrawberries.)
The update should rewrite configuration option names in capital letters. However lines beginning with hashes and any parameter data must not be altered (eg the banana for favourite fruit must not become capitalized). The update process should also replace double semicolon prefixes with just a single semicolon (unless it is uncommenting the option, in which case it should remove all leading semicolons).
Any lines beginning with a semicolon or groups of semicolons, but no following option should be removed, as should any leading or trailing whitespace on the lines. Whitespace between the option and parameters should consist only of a single
space, and any non-ASCII extended characters, tabs characters, or control codes
(other than end of line markers), should also be removed.
Related tasks
Read a configuration file
| #Raku | Raku | conf-update --/needspeeling --seedsremoved --numberofbananas=1024 --numberofstrawberries=62000 test.cfg |
http://rosettacode.org/wiki/User_input/Text | User input/Text | User input/Text is part of Short Circuit's Console Program Basics selection.
Task
Input a string and the integer 75000 from the text console.
See also: User input/Graphical
| #Icon_and_Unicon | Icon and Unicon |
procedure main ()
writes ("Enter something: ")
s := read ()
write ("You entered: " || s)
writes ("Enter 75000: ")
if (i := integer (read ())) then
write (if (i = 75000) then "correct" else "incorrect")
else write ("you must enter a number")
end
|
http://rosettacode.org/wiki/User_input/Text | User input/Text | User input/Text is part of Short Circuit's Console Program Basics selection.
Task
Input a string and the integer 75000 from the text console.
See also: User input/Graphical
| #Io | Io | string := File clone standardInput readLine("Enter a string: ")
integer := File clone standardInput readLine("Enter 75000: ") asNumber |
http://rosettacode.org/wiki/User_input/Graphical | User input/Graphical |
In this task, the goal is to input a string and the integer 75000, from graphical user interface.
See also: User input/Text
| #Perl | Perl | use Wx;
package MyApp;
use base 'Wx::App';
use Wx qw(wxHORIZONTAL wxVERTICAL wxALL wxALIGN_CENTER);
use Wx::Event 'EVT_BUTTON';
our ($frame, $text_input, $integer_input);
sub OnInit
{$frame = new Wx::Frame
(undef, -1, 'Input window', [-1, -1], [250, 150]);
my $panel = new Wx::Panel($frame, -1);
$text_input = new Wx::TextCtrl($panel, -1, '');
$integer_input = new Wx::SpinCtrl
($panel, -1, '', [-1, -1], [-1, -1],
0, 0, 100_000);
my $okay_button = new Wx::Button($panel, -1, 'OK');
EVT_BUTTON($frame, $okay_button, \&OnQuit);
my $sizer = new Wx::BoxSizer(wxVERTICAL);
$sizer->Add($_, 0, wxALL | wxALIGN_CENTER, 5)
foreach $text_input, $integer_input, $okay_button;
$panel->SetSizer($sizer);
$frame->Show(1);}
sub OnQuit
{print 'String: ', $text_input->GetValue, "\n";
print 'Integer: ', $integer_input->GetValue, "\n";
$frame->Close;}
# ---------------------------------------------------------------
package main;
MyApp->new->MainLoop; |
http://rosettacode.org/wiki/UTF-8_encode_and_decode | UTF-8 encode and decode | As described in UTF-8 and in Wikipedia, UTF-8 is a popular encoding of (multi-byte) Unicode code-points into eight-bit octets.
The goal of this task is to write a encoder that takes a unicode code-point (an integer representing a unicode character) and returns a sequence of 1-4 bytes representing that character in the UTF-8 encoding.
Then you have to write the corresponding decoder that takes a sequence of 1-4 UTF-8 encoded bytes and return the corresponding unicode character.
Demonstrate the functionality of your encoder and decoder on the following five characters:
Character Name Unicode UTF-8 encoding (hex)
---------------------------------------------------------------------------------
A LATIN CAPITAL LETTER A U+0041 41
ö LATIN SMALL LETTER O WITH DIAERESIS U+00F6 C3 B6
Ж CYRILLIC CAPITAL LETTER ZHE U+0416 D0 96
€ EURO SIGN U+20AC E2 82 AC
𝄞 MUSICAL SYMBOL G CLEF U+1D11E F0 9D 84 9E
Provided below is a reference implementation in Common Lisp.
| #Python | Python |
#!/usr/bin/env python3
from unicodedata import name
def unicode_code(ch):
return 'U+{:04x}'.format(ord(ch))
def utf8hex(ch):
return " ".join([hex(c)[2:] for c in ch.encode('utf8')]).upper()
if __name__ == "__main__":
print('{:<11} {:<36} {:<15} {:<15}'.format('Character', 'Name', 'Unicode', 'UTF-8 encoding (hex)'))
chars = ['A', 'ö', 'Ж', '€', '𝄞']
for char in chars:
print('{:<11} {:<36} {:<15} {:<15}'.format(char, name(char), unicode_code(char), utf8hex(char))) |
http://rosettacode.org/wiki/UTF-8_encode_and_decode | UTF-8 encode and decode | As described in UTF-8 and in Wikipedia, UTF-8 is a popular encoding of (multi-byte) Unicode code-points into eight-bit octets.
The goal of this task is to write a encoder that takes a unicode code-point (an integer representing a unicode character) and returns a sequence of 1-4 bytes representing that character in the UTF-8 encoding.
Then you have to write the corresponding decoder that takes a sequence of 1-4 UTF-8 encoded bytes and return the corresponding unicode character.
Demonstrate the functionality of your encoder and decoder on the following five characters:
Character Name Unicode UTF-8 encoding (hex)
---------------------------------------------------------------------------------
A LATIN CAPITAL LETTER A U+0041 41
ö LATIN SMALL LETTER O WITH DIAERESIS U+00F6 C3 B6
Ж CYRILLIC CAPITAL LETTER ZHE U+0416 D0 96
€ EURO SIGN U+20AC E2 82 AC
𝄞 MUSICAL SYMBOL G CLEF U+1D11E F0 9D 84 9E
Provided below is a reference implementation in Common Lisp.
| #Racket | Racket | #lang racket
(define char-map
'((LATIN-CAPITAL-LETTER-A . #\U0041)
(LATIN-SMALL-LETTER-O-WITH-DIAERESIS . #\U00F6)
(CYRILLIC-CAPITAL-LETTER-ZHE . #\U0416)
(EURO-SIGN . #\U20AC)
(MUSICAL-SYMBOL-G-CLEF . #\U1D11E)))
(for ((name.char (in-list char-map)))
(define name (car name.char))
(define chr (cdr name.char))
(let ((bites (bytes->list (string->bytes/utf-8 (list->string (list chr))))))
(printf "~s\t~a\t~a\t~a\t~a~%" chr chr
(map (curryr number->string 16) bites)
(bytes->string/utf-8 (list->bytes bites))
name))) |
http://rosettacode.org/wiki/URL_encoding | URL encoding | Task
Provide a function or mechanism to convert a provided string into URL encoding representation.
In URL encoding, special characters, control characters and extended characters
are converted into a percent symbol followed by a two digit hexadecimal code,
So a space character encodes into %20 within the string.
For the purposes of this task, every character except 0-9, A-Z and a-z requires conversion, so the following characters all require conversion by default:
ASCII control codes (Character ranges 00-1F hex (0-31 decimal) and 7F (127 decimal).
ASCII symbols (Character ranges 32-47 decimal (20-2F hex))
ASCII symbols (Character ranges 58-64 decimal (3A-40 hex))
ASCII symbols (Character ranges 91-96 decimal (5B-60 hex))
ASCII symbols (Character ranges 123-126 decimal (7B-7E hex))
Extended characters with character codes of 128 decimal (80 hex) and above.
Example
The string "http://foo bar/" would be encoded as "http%3A%2F%2Ffoo%20bar%2F".
Variations
Lowercase escapes are legal, as in "http%3a%2f%2ffoo%20bar%2f".
Some standards give different rules: RFC 3986, Uniform Resource Identifier (URI): Generic Syntax, section 2.3, says that "-._~" should not be encoded. HTML 5, section 4.10.22.5 URL-encoded form data, says to preserve "-._*", and to encode space " " to "+". The options below provide for utilization of an exception string, enabling preservation (non encoding) of particular characters to meet specific standards.
Options
It is permissible to use an exception string (containing a set of symbols
that do not need to be converted).
However, this is an optional feature and is not a requirement of this task.
Related tasks
URL decoding
URL parser
| #Oberon-2 | Oberon-2 |
MODULE URLEncoding;
IMPORT
Out := NPCT:Console,
ADT:StringBuffer,
URI := URI:String;
VAR
encodedUrl: StringBuffer.StringBuffer;
BEGIN
encodedUrl := NEW(StringBuffer.StringBuffer,512);
URI.AppendEscaped("http://foo bar/","",encodedUrl);
Out.String(encodedUrl.ToString());Out.Ln
END URLEncoding.
|
http://rosettacode.org/wiki/URL_encoding | URL encoding | Task
Provide a function or mechanism to convert a provided string into URL encoding representation.
In URL encoding, special characters, control characters and extended characters
are converted into a percent symbol followed by a two digit hexadecimal code,
So a space character encodes into %20 within the string.
For the purposes of this task, every character except 0-9, A-Z and a-z requires conversion, so the following characters all require conversion by default:
ASCII control codes (Character ranges 00-1F hex (0-31 decimal) and 7F (127 decimal).
ASCII symbols (Character ranges 32-47 decimal (20-2F hex))
ASCII symbols (Character ranges 58-64 decimal (3A-40 hex))
ASCII symbols (Character ranges 91-96 decimal (5B-60 hex))
ASCII symbols (Character ranges 123-126 decimal (7B-7E hex))
Extended characters with character codes of 128 decimal (80 hex) and above.
Example
The string "http://foo bar/" would be encoded as "http%3A%2F%2Ffoo%20bar%2F".
Variations
Lowercase escapes are legal, as in "http%3a%2f%2ffoo%20bar%2f".
Some standards give different rules: RFC 3986, Uniform Resource Identifier (URI): Generic Syntax, section 2.3, says that "-._~" should not be encoded. HTML 5, section 4.10.22.5 URL-encoded form data, says to preserve "-._*", and to encode space " " to "+". The options below provide for utilization of an exception string, enabling preservation (non encoding) of particular characters to meet specific standards.
Options
It is permissible to use an exception string (containing a set of symbols
that do not need to be converted).
However, this is an optional feature and is not a requirement of this task.
Related tasks
URL decoding
URL parser
| #Objeck | Objeck |
use FastCgi;
bundle Default {
class UrlEncode {
function : Main(args : String[]) ~ Nil {
url := "http://foo bar/";
UrlUtility->Encode(url)->PrintLine();
}
}
}
|
http://rosettacode.org/wiki/Variables | Variables | Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| #Lambdatalk | Lambdatalk |
1) working in a global scope
{def A 3}
-> A // A is in the global scope
{def B 4}
-> B // B is in the global scopel
{def MUL {lambda {:x :y} {* :x :y}}}
-> MUL // MUL is a global function
{MUL {A} {B}} // using global variables
-> 12
2) working in a local scope
{let // open local scope
{ // begin defining and assigning local variables
{:a 3} // :a is local
{:b 4} // :b is local
{:mul {lambda {:x :y} {* :x :y}}} // :mul is a local function
} // end defining and assigning local variables
{:mul :a :b} // computing with local variables
} // closing local scope
-> 12
|
http://rosettacode.org/wiki/Van_Eck_sequence | Van Eck sequence | The sequence is generated by following this pseudo-code:
A: The first term is zero.
Repeatedly apply:
If the last term is *new* to the sequence so far then:
B: The next term is zero.
Otherwise:
C: The next term is how far back this last term occured previously.
Example
Using A:
0
Using B:
0 0
Using C:
0 0 1
Using B:
0 0 1 0
Using C: (zero last occurred two steps back - before the one)
0 0 1 0 2
Using B:
0 0 1 0 2 0
Using C: (two last occurred two steps back - before the zero)
0 0 1 0 2 0 2 2
Using C: (two last occurred one step back)
0 0 1 0 2 0 2 2 1
Using C: (one last appeared six steps back)
0 0 1 0 2 0 2 2 1 6
...
Task
Create a function/procedure/method/subroutine/... to generate the Van Eck sequence of numbers.
Use it to display here, on this page:
The first ten terms of the sequence.
Terms 991 - to - 1000 of the sequence.
References
Don't Know (the Van Eck Sequence) - Numberphile video.
Wikipedia Article: Van Eck's Sequence.
OEIS sequence: A181391.
| #SNOBOL4 | SNOBOL4 | define('eck(n)i,j') :(eck_end)
eck eck = array(n,0)
i = 0
eouter i = lt(i,n - 1) i + 1 :f(return)
j = i
einner j = gt(j,0) j - 1 :f(eouter)
eck<i + 1> = eq(eck<i>,eck<j>) i - j :s(eouter)f(einner)
eck_end
define('list(arr,start,stop)') :(list_end)
list list = list arr<start> ' '
start = lt(start,stop) start + 1 :s(list)f(return)
list_end
ecks = eck(1000)
output = list(ecks, 1, 10)
output = list(ecks, 991, 1000)
end |
http://rosettacode.org/wiki/Van_Eck_sequence | Van Eck sequence | The sequence is generated by following this pseudo-code:
A: The first term is zero.
Repeatedly apply:
If the last term is *new* to the sequence so far then:
B: The next term is zero.
Otherwise:
C: The next term is how far back this last term occured previously.
Example
Using A:
0
Using B:
0 0
Using C:
0 0 1
Using B:
0 0 1 0
Using C: (zero last occurred two steps back - before the one)
0 0 1 0 2
Using B:
0 0 1 0 2 0
Using C: (two last occurred two steps back - before the zero)
0 0 1 0 2 0 2 2
Using C: (two last occurred one step back)
0 0 1 0 2 0 2 2 1
Using C: (one last appeared six steps back)
0 0 1 0 2 0 2 2 1 6
...
Task
Create a function/procedure/method/subroutine/... to generate the Van Eck sequence of numbers.
Use it to display here, on this page:
The first ten terms of the sequence.
Terms 991 - to - 1000 of the sequence.
References
Don't Know (the Van Eck Sequence) - Numberphile video.
Wikipedia Article: Van Eck's Sequence.
OEIS sequence: A181391.
| #Sidef | Sidef | func van_eck(n) {
var seen = Hash()
var seq = [0]
var prev = seq[-1]
for k in (1 ..^ n) {
seq << (seen.has(prev) ? (k - seen{prev}) : 0)
seen{prev} = k
prev = seq[-1]
}
seq
}
say van_eck(10)
say van_eck(1000).slice(991-1, 1000-1) |
http://rosettacode.org/wiki/Variadic_function | Variadic function | Task
Create a function which takes in a variable number of arguments and prints each one on its own line.
Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime.
Functions of this type are also known as Variadic Functions.
Related task
Call a function
| #Ring | Ring |
# Project : Variadic function
sum([1,2])
sum([1,2,3])
nums = [1,2,3,4]
sum(nums)
func sum(nums)
total = 0
for num = 1 to len(nums)
total = total + num
next
showarray(nums)
see " " + total + nl
func showarray(vect)
see "["
svect = ""
for n = 1 to len(vect)
svect = svect + vect[n] + " "
next
svect = left(svect, len(svect) - 1)
see "" + svect + "]"
|
http://rosettacode.org/wiki/Variadic_function | Variadic function | Task
Create a function which takes in a variable number of arguments and prints each one on its own line.
Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime.
Functions of this type are also known as Variadic Functions.
Related task
Call a function
| #Ruby | Ruby | def print_all(*things)
puts things
end |
http://rosettacode.org/wiki/Variadic_function | Variadic function | Task
Create a function which takes in a variable number of arguments and prints each one on its own line.
Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime.
Functions of this type are also known as Variadic Functions.
Related task
Call a function
| #Rust | Rust | // 20220106 Rust programming solution
macro_rules! print_all {
($($args:expr),*) => { $( println!("{}", $args); )* }
}
fn main() {
print_all!("Rosetta", "Code", "Is", "Awesome!");
} |
http://rosettacode.org/wiki/Vector_products | Vector products | A vector is defined as having three dimensions as being represented by an ordered collection of three numbers: (X, Y, Z).
If you imagine a graph with the x and y axis being at right angles to each other and having a third, z axis coming out of the page, then a triplet of numbers, (X, Y, Z) would represent a point in the region, and a vector from the origin to the point.
Given the vectors:
A = (a1, a2, a3)
B = (b1, b2, b3)
C = (c1, c2, c3)
then the following common vector products are defined:
The dot product (a scalar quantity)
A • B = a1b1 + a2b2 + a3b3
The cross product (a vector quantity)
A x B = (a2b3 - a3b2, a3b1 - a1b3, a1b2 - a2b1)
The scalar triple product (a scalar quantity)
A • (B x C)
The vector triple product (a vector quantity)
A x (B x C)
Task
Given the three vectors:
a = ( 3, 4, 5)
b = ( 4, 3, 5)
c = (-5, -12, -13)
Create a named function/subroutine/method to compute the dot product of two vectors.
Create a function to compute the cross product of two vectors.
Optionally create a function to compute the scalar triple product of three vectors.
Optionally create a function to compute the vector triple product of three vectors.
Compute and display: a • b
Compute and display: a x b
Compute and display: a • (b x c), the scalar triple product.
Compute and display: a x (b x c), the vector triple product.
References
A starting page on Wolfram MathWorld is Vector Multiplication .
Wikipedia dot product.
Wikipedia cross product.
Wikipedia triple product.
Related tasks
Dot product
Quaternion type
| #Java | Java | public class VectorProds{
public static class Vector3D<T extends Number>{
private T a, b, c;
public Vector3D(T a, T b, T c){
this.a = a;
this.b = b;
this.c = c;
}
public double dot(Vector3D<?> vec){
return (a.doubleValue() * vec.a.doubleValue() +
b.doubleValue() * vec.b.doubleValue() +
c.doubleValue() * vec.c.doubleValue());
}
public Vector3D<Double> cross(Vector3D<?> vec){
Double newA = b.doubleValue()*vec.c.doubleValue() - c.doubleValue()*vec.b.doubleValue();
Double newB = c.doubleValue()*vec.a.doubleValue() - a.doubleValue()*vec.c.doubleValue();
Double newC = a.doubleValue()*vec.b.doubleValue() - b.doubleValue()*vec.a.doubleValue();
return new Vector3D<Double>(newA, newB, newC);
}
public double scalTrip(Vector3D<?> vecB, Vector3D<?> vecC){
return this.dot(vecB.cross(vecC));
}
public Vector3D<Double> vecTrip(Vector3D<?> vecB, Vector3D<?> vecC){
return this.cross(vecB.cross(vecC));
}
@Override
public String toString(){
return "<" + a.toString() + ", " + b.toString() + ", " + c.toString() + ">";
}
}
public static void main(String[] args){
Vector3D<Integer> a = new Vector3D<Integer>(3, 4, 5);
Vector3D<Integer> b = new Vector3D<Integer>(4, 3, 5);
Vector3D<Integer> c = new Vector3D<Integer>(-5, -12, -13);
System.out.println(a.dot(b));
System.out.println(a.cross(b));
System.out.println(a.scalTrip(b, c));
System.out.println(a.vecTrip(b, c));
}
} |
http://rosettacode.org/wiki/Validate_International_Securities_Identification_Number | Validate International Securities Identification Number | An International Securities Identification Number (ISIN) is a unique international identifier for a financial security such as a stock or bond.
Task
Write a function or program that takes a string as input, and checks whether it is a valid ISIN.
It is only valid if it has the correct format, and the embedded checksum is correct.
Demonstrate that your code passes the test-cases listed below.
Details
The format of an ISIN is as follows:
┌───────────── a 2-character ISO country code (A-Z)
│ ┌─────────── a 9-character security code (A-Z, 0-9)
│ │ ┌── a checksum digit (0-9)
AU0000XVGZA3
For this task, you may assume that any 2-character alphabetic sequence is a valid country code.
The checksum can be validated as follows:
Replace letters with digits, by converting each character from base 36 to base 10, e.g. AU0000XVGZA3 →1030000033311635103.
Perform the Luhn test on this base-10 number.
There is a separate task for this test: Luhn test of credit card numbers.
You don't have to replicate the implementation of this test here ─── you can just call the existing function from that task. (Add a comment stating if you did this.)
Test cases
ISIN
Validity
Comment
US0378331005
valid
US0373831005
not valid
The transposition typo is caught by the checksum constraint.
U50378331005
not valid
The substitution typo is caught by the format constraint.
US03378331005
not valid
The duplication typo is caught by the format constraint.
AU0000XVGZA3
valid
AU0000VXGZA3
valid
Unfortunately, not all transposition typos are caught by the checksum constraint.
FR0000988040
valid
(The comments are just informational. Your function should simply return a Boolean result. See #Raku for a reference solution.)
Related task:
Luhn test of credit card numbers
Also see
Interactive online ISIN validator
Wikipedia article: International Securities Identification Number
| #VBScript | VBScript | ' Validate International Securities Identification Number - 03/03/2019
buf=buf&test("US0378331005")&vbCrLf
buf=buf&test("US0373831005")&vbCrLf
buf=buf&test("U50378331005")&vbCrLf
buf=buf&test("US03378331005")&vbCrLf
buf=buf&test("AU0000XVGZA3")&vbCrLf
buf=buf&test("AU0000VXGZA3")&vbCrLf
buf=buf&test("FR0000988040")&vbCrLf
msgbox buf,,"Validate International Securities Identification Number"
function test(cc)
dim err,c,r,s,i1,i2
if len(cc)=12 then
for i=1 to len(cc)
p=instr("0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ",mid(cc,i,1))
if p<>0 then c=c&(p-1) else err=1
next 'i
for i=1 to 2
if instr("ABCDEFGHIJKLMNOPQRSTUVWXYZ",mid(cc,i,1))=0 then err=1
next 'i
if err=0 then
for i=len(c) to 1 step -1
r=r&mid(c,i,1)
next 'i
for i=1 to len(r) step 2
i1=i1+cint(mid(r,i,1))
next 'i
for i=2 to len(r) step 2
ii=cint(mid(r,i,1))*2
if ii>=10 then ii=ii-9
i2=i2+ii
next 'i
s=cstr(i1+i2)
if mid(s,len(s),1)="0" then
msg="valid"
else
msg="invalid ??1"
end if
else
msg="invalid ??2"
end if
else
msg="invalid ??3"
end if
test=cc&" "&msg
end function 'test |
http://rosettacode.org/wiki/Validate_International_Securities_Identification_Number | Validate International Securities Identification Number | An International Securities Identification Number (ISIN) is a unique international identifier for a financial security such as a stock or bond.
Task
Write a function or program that takes a string as input, and checks whether it is a valid ISIN.
It is only valid if it has the correct format, and the embedded checksum is correct.
Demonstrate that your code passes the test-cases listed below.
Details
The format of an ISIN is as follows:
┌───────────── a 2-character ISO country code (A-Z)
│ ┌─────────── a 9-character security code (A-Z, 0-9)
│ │ ┌── a checksum digit (0-9)
AU0000XVGZA3
For this task, you may assume that any 2-character alphabetic sequence is a valid country code.
The checksum can be validated as follows:
Replace letters with digits, by converting each character from base 36 to base 10, e.g. AU0000XVGZA3 →1030000033311635103.
Perform the Luhn test on this base-10 number.
There is a separate task for this test: Luhn test of credit card numbers.
You don't have to replicate the implementation of this test here ─── you can just call the existing function from that task. (Add a comment stating if you did this.)
Test cases
ISIN
Validity
Comment
US0378331005
valid
US0373831005
not valid
The transposition typo is caught by the checksum constraint.
U50378331005
not valid
The substitution typo is caught by the format constraint.
US03378331005
not valid
The duplication typo is caught by the format constraint.
AU0000XVGZA3
valid
AU0000VXGZA3
valid
Unfortunately, not all transposition typos are caught by the checksum constraint.
FR0000988040
valid
(The comments are just informational. Your function should simply return a Boolean result. See #Raku for a reference solution.)
Related task:
Luhn test of credit card numbers
Also see
Interactive online ISIN validator
Wikipedia article: International Securities Identification Number
| #Visual_Basic | Visual Basic | Function IsValidISIN(ByVal ISIN As String) As Boolean
Dim s As String, c As String
Dim i As Long
If Len(ISIN) = 12 Then
For i = 1 To Len(ISIN)
c = UCase$(Mid(ISIN, i, 1))
Select Case c
Case "A" To "Z"
If i = 12 Then Exit Function
s = s & CStr(Asc(c) - 55)
Case "0" To "9"
If i < 3 Then Exit Function
s = s & c
Case Else
Exit Function
End Select
Next i
IsValidISIN = LuhnCheckPassed(s)
End If
End Function |
http://rosettacode.org/wiki/Van_der_Corput_sequence | Van der Corput sequence | When counting integers in binary, if you put a (binary) point to the righEasyLangt of the count then the column immediately to the left denotes a digit with a multiplier of
2
0
{\displaystyle 2^{0}}
; the digit in the next column to the left has a multiplier of
2
1
{\displaystyle 2^{1}}
; and so on.
So in the following table:
0.
1.
10.
11.
...
the binary number "10" is
1
×
2
1
+
0
×
2
0
{\displaystyle 1\times 2^{1}+0\times 2^{0}}
.
You can also have binary digits to the right of the “point”, just as in the decimal number system. In that case, the digit in the place immediately to the right of the point has a weight of
2
−
1
{\displaystyle 2^{-1}}
, or
1
/
2
{\displaystyle 1/2}
.
The weight for the second column to the right of the point is
2
−
2
{\displaystyle 2^{-2}}
or
1
/
4
{\displaystyle 1/4}
. And so on.
If you take the integer binary count of the first table, and reflect the digits about the binary point, you end up with the van der Corput sequence of numbers in base 2.
.0
.1
.01
.11
...
The third member of the sequence, binary 0.01, is therefore
0
×
2
−
1
+
1
×
2
−
2
{\displaystyle 0\times 2^{-1}+1\times 2^{-2}}
or
1
/
4
{\displaystyle 1/4}
.
Distribution of 2500 points each: Van der Corput (top) vs pseudorandom
0
≤
x
<
1
{\displaystyle 0\leq x<1}
Monte Carlo simulations
This sequence is also a superset of the numbers representable by the "fraction" field of an old IEEE floating point standard. In that standard, the "fraction" field represented the fractional part of a binary number beginning with "1." e.g. 1.101001101.
Hint
A hint at a way to generate members of the sequence is to modify a routine used to change the base of an integer:
>>> def base10change(n, base):
digits = []
while n:
n,remainder = divmod(n, base)
digits.insert(0, remainder)
return digits
>>> base10change(11, 2)
[1, 0, 1, 1]
the above showing that 11 in decimal is
1
×
2
3
+
0
×
2
2
+
1
×
2
1
+
1
×
2
0
{\displaystyle 1\times 2^{3}+0\times 2^{2}+1\times 2^{1}+1\times 2^{0}}
.
Reflected this would become .1101 or
1
×
2
−
1
+
1
×
2
−
2
+
0
×
2
−
3
+
1
×
2
−
4
{\displaystyle 1\times 2^{-1}+1\times 2^{-2}+0\times 2^{-3}+1\times 2^{-4}}
Task description
Create a function/method/routine that given n, generates the n'th term of the van der Corput sequence in base 2.
Use the function to compute and display the first ten members of the sequence. (The first member of the sequence is for n=0).
As a stretch goal/extra credit, compute and show members of the sequence for bases other than 2.
See also
The Basic Low Discrepancy Sequences
Non-decimal radices/Convert
Van der Corput sequence
| #Ring | Ring |
decimals(4)
for base = 2 to 5
see "base " + string(base) + " : "
for number = 0 to 9
see "" + corput(number, base) + " "
next
see nl
next
func corput n, b
vdc = 0
denom = 1
while n
denom *= b
rem = n % b
n = floor(n/b)
vdc += rem / denom
end
return vdc
|
http://rosettacode.org/wiki/Van_der_Corput_sequence | Van der Corput sequence | When counting integers in binary, if you put a (binary) point to the righEasyLangt of the count then the column immediately to the left denotes a digit with a multiplier of
2
0
{\displaystyle 2^{0}}
; the digit in the next column to the left has a multiplier of
2
1
{\displaystyle 2^{1}}
; and so on.
So in the following table:
0.
1.
10.
11.
...
the binary number "10" is
1
×
2
1
+
0
×
2
0
{\displaystyle 1\times 2^{1}+0\times 2^{0}}
.
You can also have binary digits to the right of the “point”, just as in the decimal number system. In that case, the digit in the place immediately to the right of the point has a weight of
2
−
1
{\displaystyle 2^{-1}}
, or
1
/
2
{\displaystyle 1/2}
.
The weight for the second column to the right of the point is
2
−
2
{\displaystyle 2^{-2}}
or
1
/
4
{\displaystyle 1/4}
. And so on.
If you take the integer binary count of the first table, and reflect the digits about the binary point, you end up with the van der Corput sequence of numbers in base 2.
.0
.1
.01
.11
...
The third member of the sequence, binary 0.01, is therefore
0
×
2
−
1
+
1
×
2
−
2
{\displaystyle 0\times 2^{-1}+1\times 2^{-2}}
or
1
/
4
{\displaystyle 1/4}
.
Distribution of 2500 points each: Van der Corput (top) vs pseudorandom
0
≤
x
<
1
{\displaystyle 0\leq x<1}
Monte Carlo simulations
This sequence is also a superset of the numbers representable by the "fraction" field of an old IEEE floating point standard. In that standard, the "fraction" field represented the fractional part of a binary number beginning with "1." e.g. 1.101001101.
Hint
A hint at a way to generate members of the sequence is to modify a routine used to change the base of an integer:
>>> def base10change(n, base):
digits = []
while n:
n,remainder = divmod(n, base)
digits.insert(0, remainder)
return digits
>>> base10change(11, 2)
[1, 0, 1, 1]
the above showing that 11 in decimal is
1
×
2
3
+
0
×
2
2
+
1
×
2
1
+
1
×
2
0
{\displaystyle 1\times 2^{3}+0\times 2^{2}+1\times 2^{1}+1\times 2^{0}}
.
Reflected this would become .1101 or
1
×
2
−
1
+
1
×
2
−
2
+
0
×
2
−
3
+
1
×
2
−
4
{\displaystyle 1\times 2^{-1}+1\times 2^{-2}+0\times 2^{-3}+1\times 2^{-4}}
Task description
Create a function/method/routine that given n, generates the n'th term of the van der Corput sequence in base 2.
Use the function to compute and display the first ten members of the sequence. (The first member of the sequence is for n=0).
As a stretch goal/extra credit, compute and show members of the sequence for bases other than 2.
See also
The Basic Low Discrepancy Sequences
Non-decimal radices/Convert
Van der Corput sequence
| #Ruby | Ruby | def vdc(n, base=2)
str = n.to_s(base).reverse
str.to_i(base).quo(base ** str.length)
end
(2..5).each do |base|
puts "Base #{base}: " + Array.new(10){|i| vdc(i,base)}.join(", ")
end |
http://rosettacode.org/wiki/URL_decoding | URL decoding | This task (the reverse of URL encoding and distinct from URL parser) is to provide a function
or mechanism to convert an URL-encoded string into its original unencoded form.
Test cases
The encoded string "http%3A%2F%2Ffoo%20bar%2F" should be reverted to the unencoded form "http://foo bar/".
The encoded string "google.com/search?q=%60Abdu%27l-Bah%C3%A1" should revert to the unencoded form "google.com/search?q=`Abdu'l-Bahá".
| #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | URLDecoding[url_] :=
StringReplace[url, "%" ~~ x_ ~~ y_ :> FromDigits[x ~~ y, 16]] //.
StringExpression[x___, Longest[n__Integer], y___] :>
StringExpression[x, FromCharacterCode[{n}, "UTF8"], y] |
http://rosettacode.org/wiki/URL_decoding | URL decoding | This task (the reverse of URL encoding and distinct from URL parser) is to provide a function
or mechanism to convert an URL-encoded string into its original unencoded form.
Test cases
The encoded string "http%3A%2F%2Ffoo%20bar%2F" should be reverted to the unencoded form "http://foo bar/".
The encoded string "google.com/search?q=%60Abdu%27l-Bah%C3%A1" should revert to the unencoded form "google.com/search?q=`Abdu'l-Bahá".
| #MATLAB_.2F_Octave | MATLAB / Octave | function u = urldecoding(s)
u = '';
k = 1;
while k<=length(s)
if s(k) == '%' && k+2 <= length(s)
u = sprintf('%s%c', u, char(hex2dec(s((k+1):(k+2)))));
k = k + 3;
else
u = sprintf('%s%c', u, s(k));
k = k + 1;
end
end
end |
http://rosettacode.org/wiki/UPC | UPC | Goal
Convert UPC bar codes to decimal.
Specifically:
The UPC standard is actually a collection of standards -- physical standards, data format standards, product reference standards...
Here, in this task, we will focus on some of the data format standards, with an imaginary physical+electrical implementation which converts physical UPC bar codes to ASCII (with spaces and # characters representing the presence or absence of ink).
Sample input
Below, we have a representation of ten different UPC-A bar codes read by our imaginary bar code reader:
# # # ## # ## # ## ### ## ### ## #### # # # ## ## # # ## ## ### # ## ## ### # # #
# # # ## ## # #### # # ## # ## # ## # # # ### # ### ## ## ### # # ### ### # # #
# # # # # ### # # # # # # # # # # ## # ## # ## # ## # # #### ### ## # #
# # ## ## ## ## # # # # ### # ## ## # # # ## ## # ### ## ## # # #### ## # # #
# # ### ## # ## ## ### ## # ## # # ## # # ### # ## ## # # ### # ## ## # # #
# # # # ## ## # # # # ## ## # # # # # #### # ## # #### #### # # ## # #### # #
# # # ## ## # # ## ## # ### ## ## # # # # # # # # ### # # ### # # # # #
# # # # ## ## # # ## ## ### # # # # # ### ## ## ### ## ### ### ## # ## ### ## # #
# # ### ## ## # # #### # ## # #### # #### # # # # # ### # # ### # # # ### # # #
# # # #### ## # #### # # ## ## ### #### # # # # ### # ### ### # # ### # # # ### # #
Some of these were entered upside down, and one entry has a timing error.
Task
Implement code to find the corresponding decimal representation of each, rejecting the error.
Extra credit for handling the rows entered upside down (the other option is to reject them).
Notes
Each digit is represented by 7 bits:
0: 0 0 0 1 1 0 1
1: 0 0 1 1 0 0 1
2: 0 0 1 0 0 1 1
3: 0 1 1 1 1 0 1
4: 0 1 0 0 0 1 1
5: 0 1 1 0 0 0 1
6: 0 1 0 1 1 1 1
7: 0 1 1 1 0 1 1
8: 0 1 1 0 1 1 1
9: 0 0 0 1 0 1 1
On the left hand side of the bar code a space represents a 0 and a # represents a 1.
On the right hand side of the bar code, a # represents a 0 and a space represents a 1
Alternatively (for the above): spaces always represent zeros and # characters always represent ones, but the representation is logically negated -- 1s and 0s are flipped -- on the right hand side of the bar code.
The UPC-A bar code structure
It begins with at least 9 spaces (which our imaginary bar code reader unfortunately doesn't always reproduce properly),
then has a # # sequence marking the start of the sequence,
then has the six "left hand" digits,
then has a # # sequence in the middle,
then has the six "right hand digits",
then has another # # (end sequence), and finally,
then ends with nine trailing spaces (which might be eaten by wiki edits, and in any event, were not quite captured correctly by our imaginary bar code reader).
Finally, the last digit is a checksum digit which may be used to help detect errors.
Verification
Multiply each digit in the represented 12 digit sequence by the corresponding number in (3,1,3,1,3,1,3,1,3,1,3,1) and add the products.
The sum (mod 10) must be 0 (must have a zero as its last digit) if the UPC number has been read correctly.
| #Perl | Perl | use strict;
use warnings;
use feature 'say';
sub decode_UPC {
my($line) = @_;
my(%pattern_to_digit_1,%pattern_to_digit_2,@patterns1,@patterns2,@digits,$sum);
for my $p (' ## #', ' ## #', ' # ##', ' #### #', ' # ##', ' ## #', ' # ####', ' ### ##', ' ## ###', ' # ##') {
push @patterns1, $p;
push @patterns2, $p =~ tr/# / #/r;
}
$pattern_to_digit_1{$patterns1[$_]} = $_ for 0..$#patterns1;
$pattern_to_digit_2{$patterns2[$_]} = $_ for 0..$#patterns2;
my $re = '\s*# #\s*' .
"(?<match1>(?:@{[join '|', @patterns1]}){6})" .
'\s*# #\s*' .
"(?<match2>(?:@{[join '|', @patterns2]}){6})" .
'\s*# #\s*';
$line =~ /^$re$/g || return;
my($match1,$match2) = ($+{match1}, $+{match2});
push @digits, $pattern_to_digit_1{$_} for $match1 =~ /(.{7})/g;
push @digits, $pattern_to_digit_2{$_} for $match2 =~ /(.{7})/g;
$sum += (3,1)[$_%2] * $digits[$_] for 0..11;
$sum % 10 ? '' : join '', @digits;
}
my @lines = (
' # # # ## # ## # ## ### ## ### ## #### # # # ## ## # # ## ## ### # ## ## ### # # # ',
' # # # ## ## # #### # # ## # ## # ## # # # ### # ### ## ## ### # # ### ### # # # ',
' # # # # # ### # # # # # # # # # # ## # ## # ## # ## # # #### ### ## # # ',
' # # ## ## ## ## # # # # ### # ## ## # # # ## ## # ### ## ## # # #### ## # # # ',
' # # ### ## # ## ## ### ## # ## # # ## # # ### # ## ## # # ### # ## ## # # # ',
' # # # # ## ## # # # # ## ## # # # # # #### # ## # #### #### # # ## # #### # # ',
' # # # ## ## # # ## ## # ### ## ## # # # # # # # # ### # # ### # # # # # ',
' # # # # ## ## # # ## ## ### # # # # # ### ## ## ### ## ### ### ## # ## ### ## # # ',
' # # ### ## ## # # #### # ## # #### # #### # # # # # ### # # ### # # # ### # # # ',
' # # # #### ## # #### # # ## ## ### #### # # # # ### # ### ### # # ### # # # ### # # ',
);
for my $line (@lines) {
say decode_UPC($line)
// decode_UPC(join '', reverse split '', $line)
// 'Invalid';
}
|
http://rosettacode.org/wiki/Update_a_configuration_file | Update a configuration file | We have a configuration file as follows:
# This is a configuration file in standard configuration file format
#
# Lines begininning with a hash or a semicolon are ignored by the application
# program. Blank lines are also ignored by the application program.
# The first word on each non comment line is the configuration option.
# Remaining words or numbers on the line are configuration parameter
# data fields.
# Note that configuration option names are not case sensitive. However,
# configuration parameter data is case sensitive and the lettercase must
# be preserved.
# This is a favourite fruit
FAVOURITEFRUIT banana
# This is a boolean that should be set
NEEDSPEELING
# This boolean is commented out
; SEEDSREMOVED
# How many bananas we have
NUMBEROFBANANAS 48
The task is to manipulate the configuration file as follows:
Disable the needspeeling option (using a semicolon prefix)
Enable the seedsremoved option by removing the semicolon and any leading whitespace
Change the numberofbananas parameter to 1024
Enable (or create if it does not exist in the file) a parameter for numberofstrawberries with a value of 62000
Note that configuration option names are not case sensitive. This means that changes should be effected, regardless of the case.
Options should always be disabled by prefixing them with a semicolon.
Lines beginning with hash symbols should not be manipulated and left unchanged in the revised file.
If a configuration option does not exist within the file (in either enabled or disabled form), it should be added during this update. Duplicate configuration option names in the file should be removed, leaving just the first entry.
For the purpose of this task, the revised file should contain appropriate entries, whether enabled or not for needspeeling,seedsremoved,numberofbananas and numberofstrawberries.)
The update should rewrite configuration option names in capital letters. However lines beginning with hashes and any parameter data must not be altered (eg the banana for favourite fruit must not become capitalized). The update process should also replace double semicolon prefixes with just a single semicolon (unless it is uncommenting the option, in which case it should remove all leading semicolons).
Any lines beginning with a semicolon or groups of semicolons, but no following option should be removed, as should any leading or trailing whitespace on the lines. Whitespace between the option and parameters should consist only of a single
space, and any non-ASCII extended characters, tabs characters, or control codes
(other than end of line markers), should also be removed.
Related tasks
Read a configuration file
| #REXX | REXX | /*REXX program demonstrates how to update a configuration file (four specific tasks).*/
parse arg iFID oFID . /*obtain optional arguments from the CL*/
if iFID=='' | iFID=="," then iFID= 'UPDATECF.TXT' /*Not given? Then use default.*/
if oFID=='' | oFID=="," then oFID='\TEMP\UPDATECF.$$$' /* " " " " " */
call lineout iFID; call lineout oFID /*close the input and the output files.*/
$.=0 /*placeholder of the options detected. */
call dos 'ERASE' oFID /*erase a file (with no error message).*/
changed=0 /*nothing changed in the file (so far).*/
/* [↓] read the entire config file. */
do rec=0 while lines(iFID)\==0 /*read a record; bump the record count.*/
z=linein(iFID); zz=space(z) /*get record; elide extraneous blanks.*/
say '───────── record:' z /*echo the record just read ──► console*/
a=left(zz,1); _=space( translate(zz, ,';') ) /*_: is used to elide multiple ";" */
if zz=='' | a=='#' then do; call cpy z; iterate; end /*blank or a comment.*/
if _=='' then do; changed=1; iterate; end /*elide any semicolons; empty records.*/
parse upper var z op . /*obtain the option from the record. */
/* [↓] option may have leading or ···*/
if a==';' then do; parse upper var z 2 op . /*trailing blanks.*/
if op='SEEDSREMOVED' then call new space( substr(z, 2) )
call cpy z; $.op=1 /*write the Z record to the output file*/
iterate /*rec*/ /* ··· and then go read the next record*/
end
if $.op then do; changed=1; iterate; end /*is the option already defined? */
$.op=1 /* [↑] Yes? Then delete it. */
if op=='NEEDSPEELING' then call new ";" z
if op=='NUMBEROFBANANAS' then call new op 1024
if op=='NUMBEROFSTRAWBERRIES' then call new op 62000
call cpy z /*write the Z record to the output file*/
end /*rec*/
nos='NUMBEROFSTRAWBERRIES' /* [↓] Does NOS option need updating? */
if \$.nos then do; call new nos 62000; call cpy z; end /*update option.*/
call lineout iFID; call lineout oFID /*close the input and the output files.*/
if rec==0 then do; say "ERROR: input file wasn't found:" iFID; exit; end
if changed then do /*possibly overwrite the input file. */
call dos 'XCOPY' oFID iFID '/y /q',">nul" /*quietly*/
say; say center('output file', 79, "▒") /*title. */
call dos 'TYPE' oFID /*display content of the output file. */
end
call dos 'ERASE' oFID /*erase a file (with no error message).*/
exit /*stick a fork in it, we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
cpy: call lineout oFID, arg(1); return /*write one line of text ───► oFID. */
dos: ''arg(1) word(arg(2) "2>nul",1); return /*execute a DOS command (quietly). */
new: z=arg(1); changed=1; return /*use new Z, indicate changed record. */ |
http://rosettacode.org/wiki/User_input/Text | User input/Text | User input/Text is part of Short Circuit's Console Program Basics selection.
Task
Input a string and the integer 75000 from the text console.
See also: User input/Graphical
| #J | J | require 'misc' NB. load system script
prompt 'Enter string: '
0".prompt 'Enter an integer: ' |
http://rosettacode.org/wiki/User_input/Text | User input/Text | User input/Text is part of Short Circuit's Console Program Basics selection.
Task
Input a string and the integer 75000 from the text console.
See also: User input/Graphical
| #Java | Java |
import java.util.Scanner;
public class GetInput {
public static void main(String[] args) throws Exception {
Scanner s = new Scanner(System.in);
System.out.print("Enter a string: ");
String str = s.nextLine();
System.out.print("Enter an integer: ");
int i = Integer.parseInt(s.next());
}
} |
http://rosettacode.org/wiki/User_input/Graphical | User input/Graphical |
In this task, the goal is to input a string and the integer 75000, from graphical user interface.
See also: User input/Text
| #Phix | Phix | -- demo\rosetta\User_Input_Graphical.exw
include pGUI.e
Ihandle dlg, label1, input1, label2, input2, OK, Cancel
function ok_cb(Ihandle self)
if self=OK then
string in1 = IupGetAttribute(input1,"VALUE")
integer in2 = IupGetInt(input2,"VALUE")
string msg = sprintf(`"%s" and %d`,{in1,in2})
IupMessage("You entered",msg)
-- (return IUP_CONTINUE if unhappy with input)
end if
return IUP_CLOSE
end function
IupOpen()
label1 = IupLabel("Please enter a string")
input1 = IupText(`VALUE="a string", EXPAND=HORIZONTAL`)
label2 = IupLabel("and the number 75000")
input2 = IupText("VALUE=75000, EXPAND=HORIZONTAL, MASK="&IUP_MASK_INT)
OK = IupButton("OK", "ACTION", Icallback("ok_cb"))
Cancel = IupButton("Cancel", "ACTION", Icallback("ok_cb"))
sequence buttons = {IupFill(),OK,Cancel,IupFill()}
Ihandle strbox = IupHbox({label1,input1},"ALIGNMENT=ACENTER, PADDING=5"),
numbox = IupHbox({label2,input2},"ALIGNMENT=ACENTER, PADDING=5"),
btnbox = IupHbox(buttons,"PADDING=40"),
vbox = IupVbox({strbox, numbox, btnbox}, "MARGIN=5x5")
if platform()!=JS then
IupSetAttribute(btnbox,"NORMALIZESIZE","BOTH")
IupSetAttribute(vbox,"GAP","5")
end if
dlg = IupDialog(vbox, `TITLE="User Input/Graphical"`)
IupShow(dlg)
if platform()!=JS then
IupMainLoop()
IupClose()
end if
|
http://rosettacode.org/wiki/UTF-8_encode_and_decode | UTF-8 encode and decode | As described in UTF-8 and in Wikipedia, UTF-8 is a popular encoding of (multi-byte) Unicode code-points into eight-bit octets.
The goal of this task is to write a encoder that takes a unicode code-point (an integer representing a unicode character) and returns a sequence of 1-4 bytes representing that character in the UTF-8 encoding.
Then you have to write the corresponding decoder that takes a sequence of 1-4 UTF-8 encoded bytes and return the corresponding unicode character.
Demonstrate the functionality of your encoder and decoder on the following five characters:
Character Name Unicode UTF-8 encoding (hex)
---------------------------------------------------------------------------------
A LATIN CAPITAL LETTER A U+0041 41
ö LATIN SMALL LETTER O WITH DIAERESIS U+00F6 C3 B6
Ж CYRILLIC CAPITAL LETTER ZHE U+0416 D0 96
€ EURO SIGN U+20AC E2 82 AC
𝄞 MUSICAL SYMBOL G CLEF U+1D11E F0 9D 84 9E
Provided below is a reference implementation in Common Lisp.
| #Raku | Raku | say sprintf("%-18s %-36s|%8s| %7s |%14s | %s\n", 'Character|', 'Name', 'Ordinal', 'Unicode', 'UTF-8 encoded', 'decoded'), '-' x 100;
for < A ö Ж € 𝄞 😜 👨👩👧👦> -> $char {
printf " %-5s | %-43s | %6s | %-7s | %12s |%4s\n", $char, $char.uninames.join(','), $char.ords.join(' '),
('U+' X~ $char.ords».base(16)).join(' '), $char.encode('UTF8').list».base(16).Str, $char.encode('UTF8').decode;
} |
http://rosettacode.org/wiki/URL_encoding | URL encoding | Task
Provide a function or mechanism to convert a provided string into URL encoding representation.
In URL encoding, special characters, control characters and extended characters
are converted into a percent symbol followed by a two digit hexadecimal code,
So a space character encodes into %20 within the string.
For the purposes of this task, every character except 0-9, A-Z and a-z requires conversion, so the following characters all require conversion by default:
ASCII control codes (Character ranges 00-1F hex (0-31 decimal) and 7F (127 decimal).
ASCII symbols (Character ranges 32-47 decimal (20-2F hex))
ASCII symbols (Character ranges 58-64 decimal (3A-40 hex))
ASCII symbols (Character ranges 91-96 decimal (5B-60 hex))
ASCII symbols (Character ranges 123-126 decimal (7B-7E hex))
Extended characters with character codes of 128 decimal (80 hex) and above.
Example
The string "http://foo bar/" would be encoded as "http%3A%2F%2Ffoo%20bar%2F".
Variations
Lowercase escapes are legal, as in "http%3a%2f%2ffoo%20bar%2f".
Some standards give different rules: RFC 3986, Uniform Resource Identifier (URI): Generic Syntax, section 2.3, says that "-._~" should not be encoded. HTML 5, section 4.10.22.5 URL-encoded form data, says to preserve "-._*", and to encode space " " to "+". The options below provide for utilization of an exception string, enabling preservation (non encoding) of particular characters to meet specific standards.
Options
It is permissible to use an exception string (containing a set of symbols
that do not need to be converted).
However, this is an optional feature and is not a requirement of this task.
Related tasks
URL decoding
URL parser
| #Objective-C | Objective-C | NSString *normal = @"http://foo bar/";
NSString *encoded = [normal stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSLog(@"%@", encoded); |
http://rosettacode.org/wiki/URL_encoding | URL encoding | Task
Provide a function or mechanism to convert a provided string into URL encoding representation.
In URL encoding, special characters, control characters and extended characters
are converted into a percent symbol followed by a two digit hexadecimal code,
So a space character encodes into %20 within the string.
For the purposes of this task, every character except 0-9, A-Z and a-z requires conversion, so the following characters all require conversion by default:
ASCII control codes (Character ranges 00-1F hex (0-31 decimal) and 7F (127 decimal).
ASCII symbols (Character ranges 32-47 decimal (20-2F hex))
ASCII symbols (Character ranges 58-64 decimal (3A-40 hex))
ASCII symbols (Character ranges 91-96 decimal (5B-60 hex))
ASCII symbols (Character ranges 123-126 decimal (7B-7E hex))
Extended characters with character codes of 128 decimal (80 hex) and above.
Example
The string "http://foo bar/" would be encoded as "http%3A%2F%2Ffoo%20bar%2F".
Variations
Lowercase escapes are legal, as in "http%3a%2f%2ffoo%20bar%2f".
Some standards give different rules: RFC 3986, Uniform Resource Identifier (URI): Generic Syntax, section 2.3, says that "-._~" should not be encoded. HTML 5, section 4.10.22.5 URL-encoded form data, says to preserve "-._*", and to encode space " " to "+". The options below provide for utilization of an exception string, enabling preservation (non encoding) of particular characters to meet specific standards.
Options
It is permissible to use an exception string (containing a set of symbols
that do not need to be converted).
However, this is an optional feature and is not a requirement of this task.
Related tasks
URL decoding
URL parser
| #OCaml | OCaml | $ ocaml
# #use "topfind";;
# #require "netstring";;
# Netencoding.Url.encode "http://foo bar/" ;;
- : string = "http%3A%2F%2Ffoo+bar%2F" |
http://rosettacode.org/wiki/Variables | Variables | Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| #Lasso | Lasso | // declare thread variable, default type null
var(x)
$x->type // null
// declare local variable, default type null
local(x)
#x->type // null
// declare thread variable, initialize with a type, in this case integer
var(x = integer)
// declare local variable, initialize with a type, in this case integer
local(x = integer)
// assign a value to the thread var x
$x = 12
// assign a value to the local var x
$x = 177
// a var always has a data type, even if not declared - then it's null
// a var can either be assigned a type using the name of the type, or a value that is by itself the type
local(y = string)
local(y = 'hello')
'\r'
// demonstrating asCopyDeep and relationship between variables:
local(original) = array('radish', 'carrot', 'cucumber', 'olive')
local(originalaswell) = #original
local(copy) = #original->asCopyDeep
iterate(#original) => {
loop_value->uppercase
}
#original // modified
//array(RADISH, CARROT, CUCUMBER, OLIVE)
'\r'
#originalaswell // modified as well as it was not a deep copy
//array(RADISH, CARROT, CUCUMBER, OLIVE)
'\r'
#copy // unmodified as it used ascopydeep
//array(RADISH, CARROT, CUCUMBER, OLIVE) |
http://rosettacode.org/wiki/Variables | Variables | Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| #Liberty_BASIC | Liberty BASIC |
'In Liberty BASIC variables are either string or numeric.
'A variable name can start with any letter and it can contain both letters and numerals, as well as dots (for example: user.firstname).
'There is no practical limit to the length of a variable name... up to ~2M characters.
'The variable names are case sensitive.
'assignments: -numeric variables. LB assumes integers unless assigned or calculated otherwise.
'Because of its Smalltalk heritage, LB integers are of arbitrarily long precision.
'They lose this if a calculation yields a non-integer, switching to floating point.
i = 1
r = 3.14
'assignments -string variables. Any string-length, from zero to ~2M.
t$ ="21:12:45"
flag$ ="TRUE"
'assignments -1D or 2D arrays
'A default array size of 10 is available. Larger arrays need pre-'DIM'ming.
height( 3) =1.87
dim height( 50)
height( 23) =123.5
potential( 3, 5) =4.5
name$( 4) ="John"
'There are no Boolean /bit variables as such.
'Arrays in a main program are global.
'However variables used in the main program code are not visible inside functions and subroutines.
'They can be declared 'global' if such visibility is desired.
'Functions can receive variables by name or by reference.
|
http://rosettacode.org/wiki/Van_Eck_sequence | Van Eck sequence | The sequence is generated by following this pseudo-code:
A: The first term is zero.
Repeatedly apply:
If the last term is *new* to the sequence so far then:
B: The next term is zero.
Otherwise:
C: The next term is how far back this last term occured previously.
Example
Using A:
0
Using B:
0 0
Using C:
0 0 1
Using B:
0 0 1 0
Using C: (zero last occurred two steps back - before the one)
0 0 1 0 2
Using B:
0 0 1 0 2 0
Using C: (two last occurred two steps back - before the zero)
0 0 1 0 2 0 2 2
Using C: (two last occurred one step back)
0 0 1 0 2 0 2 2 1
Using C: (one last appeared six steps back)
0 0 1 0 2 0 2 2 1 6
...
Task
Create a function/procedure/method/subroutine/... to generate the Van Eck sequence of numbers.
Use it to display here, on this page:
The first ten terms of the sequence.
Terms 991 - to - 1000 of the sequence.
References
Don't Know (the Van Eck Sequence) - Numberphile video.
Wikipedia Article: Van Eck's Sequence.
OEIS sequence: A181391.
| #Swift | Swift | struct VanEckSequence: Sequence, IteratorProtocol {
private var index = 0
private var lastTerm = 0
private var lastPos = Dictionary<Int, Int>()
mutating func next() -> Int? {
let result = lastTerm
var nextTerm = 0
if let v = lastPos[lastTerm] {
nextTerm = index - v
}
lastPos[lastTerm] = index
lastTerm = nextTerm
index += 1
return result
}
}
let seq = VanEckSequence().prefix(1000)
print("First 10 terms of the Van Eck sequence:")
for n in seq.prefix(10) {
print(n, terminator: " ")
}
print("\nTerms 991 to 1000 of the Van Eck sequence:")
for n in seq.dropFirst(990) {
print(n, terminator: " ")
}
print() |
http://rosettacode.org/wiki/Van_Eck_sequence | Van Eck sequence | The sequence is generated by following this pseudo-code:
A: The first term is zero.
Repeatedly apply:
If the last term is *new* to the sequence so far then:
B: The next term is zero.
Otherwise:
C: The next term is how far back this last term occured previously.
Example
Using A:
0
Using B:
0 0
Using C:
0 0 1
Using B:
0 0 1 0
Using C: (zero last occurred two steps back - before the one)
0 0 1 0 2
Using B:
0 0 1 0 2 0
Using C: (two last occurred two steps back - before the zero)
0 0 1 0 2 0 2 2
Using C: (two last occurred one step back)
0 0 1 0 2 0 2 2 1
Using C: (one last appeared six steps back)
0 0 1 0 2 0 2 2 1 6
...
Task
Create a function/procedure/method/subroutine/... to generate the Van Eck sequence of numbers.
Use it to display here, on this page:
The first ten terms of the sequence.
Terms 991 - to - 1000 of the sequence.
References
Don't Know (the Van Eck Sequence) - Numberphile video.
Wikipedia Article: Van Eck's Sequence.
OEIS sequence: A181391.
| #Tcl | Tcl | ## Mathematically, the first term has index "0", not "1". We do that, also.
set ::vE 0
proc vanEck {n} {
global vE vEocc
while {$n >= [set k [expr {[llength $vE] - 1}]]} {
set kv [lindex $vE $k]
## value $kv @ $k is not yet stuffed into vEocc()
lappend vE [expr {[info exists vEocc($kv)] ? $k - $vEocc($kv) : 0}]
set vEocc($kv) $k
}
return [lindex $vE $n]
}
proc show {func from to} {
for {set n $from} {$n <= $to} {incr n} {
append r " " [$func $n]
}
puts "${func}($from..$to) =$r"
}
show vanEck 0 9
show vanEck 990 999 |
http://rosettacode.org/wiki/Variadic_function | Variadic function | Task
Create a function which takes in a variable number of arguments and prints each one on its own line.
Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime.
Functions of this type are also known as Variadic Functions.
Related task
Call a function
| #Scala | Scala | def printAll(args: Any*) = args foreach println |
http://rosettacode.org/wiki/Variadic_function | Variadic function | Task
Create a function which takes in a variable number of arguments and prints each one on its own line.
Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime.
Functions of this type are also known as Variadic Functions.
Related task
Call a function
| #Scheme | Scheme | (define (print-all . things)
(for-each
(lambda (x) (display x) (newline))
things)) |
http://rosettacode.org/wiki/Variadic_function | Variadic function | Task
Create a function which takes in a variable number of arguments and prints each one on its own line.
Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime.
Functions of this type are also known as Variadic Functions.
Related task
Call a function
| #Sidef | Sidef | func print_all(*things) {
things.each { |x| say x };
} |
http://rosettacode.org/wiki/Vector_products | Vector products | A vector is defined as having three dimensions as being represented by an ordered collection of three numbers: (X, Y, Z).
If you imagine a graph with the x and y axis being at right angles to each other and having a third, z axis coming out of the page, then a triplet of numbers, (X, Y, Z) would represent a point in the region, and a vector from the origin to the point.
Given the vectors:
A = (a1, a2, a3)
B = (b1, b2, b3)
C = (c1, c2, c3)
then the following common vector products are defined:
The dot product (a scalar quantity)
A • B = a1b1 + a2b2 + a3b3
The cross product (a vector quantity)
A x B = (a2b3 - a3b2, a3b1 - a1b3, a1b2 - a2b1)
The scalar triple product (a scalar quantity)
A • (B x C)
The vector triple product (a vector quantity)
A x (B x C)
Task
Given the three vectors:
a = ( 3, 4, 5)
b = ( 4, 3, 5)
c = (-5, -12, -13)
Create a named function/subroutine/method to compute the dot product of two vectors.
Create a function to compute the cross product of two vectors.
Optionally create a function to compute the scalar triple product of three vectors.
Optionally create a function to compute the vector triple product of three vectors.
Compute and display: a • b
Compute and display: a x b
Compute and display: a • (b x c), the scalar triple product.
Compute and display: a x (b x c), the vector triple product.
References
A starting page on Wolfram MathWorld is Vector Multiplication .
Wikipedia dot product.
Wikipedia cross product.
Wikipedia triple product.
Related tasks
Dot product
Quaternion type
| #JavaScript | JavaScript | function dotProduct() {
var len = arguments[0] && arguments[0].length;
var argsLen = arguments.length;
var i, j = len;
var prod, sum = 0;
// If no arguments supplied, return undefined
if (!len) {
return;
}
// If all vectors not same length, return undefined
i = argsLen;
while (i--) {
if (arguments[i].length != len) {
return; // return undefined
}
}
// Sum terms
while (j--) {
i = argsLen;
prod = 1;
while (i--) {
prod *= arguments[i][j];
}
sum += prod;
}
return sum;
}
function crossProduct(a, b) {
// Check lengths
if (a.length != 3 || b.length != 3) {
return;
}
return [a[1]*b[2] - a[2]*b[1],
a[2]*b[0] - a[0]*b[2],
a[0]*b[1] - a[1]*b[0]];
}
function scalarTripleProduct(a, b, c) {
return dotProduct(a, crossProduct(b, c));
}
function vectorTripleProduct(a, b, c) {
return crossProduct(a, crossProduct(b, c));
}
// Run tests
(function () {
var a = [3, 4, 5];
var b = [4, 3, 5];
var c = [-5, -12, -13];
alert(
'A . B: ' + dotProduct(a, b) +
'\n' +
'A x B: ' + crossProduct(a, b) +
'\n' +
'A . (B x C): ' + scalarTripleProduct(a, b, c) +
'\n' +
'A x (B x C): ' + vectorTripleProduct(a, b, c)
);
}()); |
http://rosettacode.org/wiki/Validate_International_Securities_Identification_Number | Validate International Securities Identification Number | An International Securities Identification Number (ISIN) is a unique international identifier for a financial security such as a stock or bond.
Task
Write a function or program that takes a string as input, and checks whether it is a valid ISIN.
It is only valid if it has the correct format, and the embedded checksum is correct.
Demonstrate that your code passes the test-cases listed below.
Details
The format of an ISIN is as follows:
┌───────────── a 2-character ISO country code (A-Z)
│ ┌─────────── a 9-character security code (A-Z, 0-9)
│ │ ┌── a checksum digit (0-9)
AU0000XVGZA3
For this task, you may assume that any 2-character alphabetic sequence is a valid country code.
The checksum can be validated as follows:
Replace letters with digits, by converting each character from base 36 to base 10, e.g. AU0000XVGZA3 →1030000033311635103.
Perform the Luhn test on this base-10 number.
There is a separate task for this test: Luhn test of credit card numbers.
You don't have to replicate the implementation of this test here ─── you can just call the existing function from that task. (Add a comment stating if you did this.)
Test cases
ISIN
Validity
Comment
US0378331005
valid
US0373831005
not valid
The transposition typo is caught by the checksum constraint.
U50378331005
not valid
The substitution typo is caught by the format constraint.
US03378331005
not valid
The duplication typo is caught by the format constraint.
AU0000XVGZA3
valid
AU0000VXGZA3
valid
Unfortunately, not all transposition typos are caught by the checksum constraint.
FR0000988040
valid
(The comments are just informational. Your function should simply return a Boolean result. See #Raku for a reference solution.)
Related task:
Luhn test of credit card numbers
Also see
Interactive online ISIN validator
Wikipedia article: International Securities Identification Number
| #Visual_Basic_.NET | Visual Basic .NET | Option Strict On
Imports System.Text.RegularExpressions
Module Module1
ReadOnly IsinRegex As New Regex("^[A-Z]{2}[A-Z0-9]{9}\d$", RegexOptions.Compiled)
Function DigitValue(c As Char) As Integer
Dim temp As Integer
If Asc(c) >= Asc("0"c) AndAlso Asc(c) <= Asc("9"c) Then
temp = Asc(c) - Asc("0"c)
Else
temp = Asc(c) - Asc("A"c) + 10
End If
Return temp
End Function
Function LuhnTest(number As String) As Boolean
Return number.Select(Function(c, i) (AscW(c) - 48) << ((number.Length - i - 1) And 1)).Sum(Function(n) If(n > 9, n - 9, n)) Mod 10 = 0
End Function
Function Digitize(isin As String) As String
Return String.Join("", isin.Select(Function(c) $"{DigitValue(c)}"))
End Function
Function IsValidIsin(isin As String) As Boolean
Return IsinRegex.IsMatch(isin) AndAlso LuhnTest(Digitize(isin))
End Function
Sub Main()
Dim isins() = {
"US0378331005",
"US0373831005",
"U50378331005",
"US03378331005",
"AU0000XVGZA3",
"AU0000VXGZA3",
"FR0000988040"
}
For Each isin In isins
If IsValidIsin(isin) Then
Console.WriteLine("{0} is valid", isin)
Else
Console.WriteLine("{0} is not valid", isin)
End If
Next
End Sub
End Module |
http://rosettacode.org/wiki/Van_der_Corput_sequence | Van der Corput sequence | When counting integers in binary, if you put a (binary) point to the righEasyLangt of the count then the column immediately to the left denotes a digit with a multiplier of
2
0
{\displaystyle 2^{0}}
; the digit in the next column to the left has a multiplier of
2
1
{\displaystyle 2^{1}}
; and so on.
So in the following table:
0.
1.
10.
11.
...
the binary number "10" is
1
×
2
1
+
0
×
2
0
{\displaystyle 1\times 2^{1}+0\times 2^{0}}
.
You can also have binary digits to the right of the “point”, just as in the decimal number system. In that case, the digit in the place immediately to the right of the point has a weight of
2
−
1
{\displaystyle 2^{-1}}
, or
1
/
2
{\displaystyle 1/2}
.
The weight for the second column to the right of the point is
2
−
2
{\displaystyle 2^{-2}}
or
1
/
4
{\displaystyle 1/4}
. And so on.
If you take the integer binary count of the first table, and reflect the digits about the binary point, you end up with the van der Corput sequence of numbers in base 2.
.0
.1
.01
.11
...
The third member of the sequence, binary 0.01, is therefore
0
×
2
−
1
+
1
×
2
−
2
{\displaystyle 0\times 2^{-1}+1\times 2^{-2}}
or
1
/
4
{\displaystyle 1/4}
.
Distribution of 2500 points each: Van der Corput (top) vs pseudorandom
0
≤
x
<
1
{\displaystyle 0\leq x<1}
Monte Carlo simulations
This sequence is also a superset of the numbers representable by the "fraction" field of an old IEEE floating point standard. In that standard, the "fraction" field represented the fractional part of a binary number beginning with "1." e.g. 1.101001101.
Hint
A hint at a way to generate members of the sequence is to modify a routine used to change the base of an integer:
>>> def base10change(n, base):
digits = []
while n:
n,remainder = divmod(n, base)
digits.insert(0, remainder)
return digits
>>> base10change(11, 2)
[1, 0, 1, 1]
the above showing that 11 in decimal is
1
×
2
3
+
0
×
2
2
+
1
×
2
1
+
1
×
2
0
{\displaystyle 1\times 2^{3}+0\times 2^{2}+1\times 2^{1}+1\times 2^{0}}
.
Reflected this would become .1101 or
1
×
2
−
1
+
1
×
2
−
2
+
0
×
2
−
3
+
1
×
2
−
4
{\displaystyle 1\times 2^{-1}+1\times 2^{-2}+0\times 2^{-3}+1\times 2^{-4}}
Task description
Create a function/method/routine that given n, generates the n'th term of the van der Corput sequence in base 2.
Use the function to compute and display the first ten members of the sequence. (The first member of the sequence is for n=0).
As a stretch goal/extra credit, compute and show members of the sequence for bases other than 2.
See also
The Basic Low Discrepancy Sequences
Non-decimal radices/Convert
Van der Corput sequence
| #Rust | Rust |
/// Van der Corput sequence for any base, based on C languange example from Wikipedia.
pub fn corput(nth: usize, base: usize) -> f64 {
let mut n = nth;
let mut q: f64 = 0.0;
let mut bk: f64 = 1.0 / (base as f64);
while n > 0_usize {
q += ((n % base) as f64)*bk;
n /= base;
bk /= base as f64;
}
q
}
fn main() {
for base in 2_usize..=5_usize {
print!("Base {}:", base);
for i in 1_usize..=10_usize {
let c = corput(i, base);
print!(" {:.6}", c)
}
println!("");
}
}
|
http://rosettacode.org/wiki/Van_der_Corput_sequence | Van der Corput sequence | When counting integers in binary, if you put a (binary) point to the righEasyLangt of the count then the column immediately to the left denotes a digit with a multiplier of
2
0
{\displaystyle 2^{0}}
; the digit in the next column to the left has a multiplier of
2
1
{\displaystyle 2^{1}}
; and so on.
So in the following table:
0.
1.
10.
11.
...
the binary number "10" is
1
×
2
1
+
0
×
2
0
{\displaystyle 1\times 2^{1}+0\times 2^{0}}
.
You can also have binary digits to the right of the “point”, just as in the decimal number system. In that case, the digit in the place immediately to the right of the point has a weight of
2
−
1
{\displaystyle 2^{-1}}
, or
1
/
2
{\displaystyle 1/2}
.
The weight for the second column to the right of the point is
2
−
2
{\displaystyle 2^{-2}}
or
1
/
4
{\displaystyle 1/4}
. And so on.
If you take the integer binary count of the first table, and reflect the digits about the binary point, you end up with the van der Corput sequence of numbers in base 2.
.0
.1
.01
.11
...
The third member of the sequence, binary 0.01, is therefore
0
×
2
−
1
+
1
×
2
−
2
{\displaystyle 0\times 2^{-1}+1\times 2^{-2}}
or
1
/
4
{\displaystyle 1/4}
.
Distribution of 2500 points each: Van der Corput (top) vs pseudorandom
0
≤
x
<
1
{\displaystyle 0\leq x<1}
Monte Carlo simulations
This sequence is also a superset of the numbers representable by the "fraction" field of an old IEEE floating point standard. In that standard, the "fraction" field represented the fractional part of a binary number beginning with "1." e.g. 1.101001101.
Hint
A hint at a way to generate members of the sequence is to modify a routine used to change the base of an integer:
>>> def base10change(n, base):
digits = []
while n:
n,remainder = divmod(n, base)
digits.insert(0, remainder)
return digits
>>> base10change(11, 2)
[1, 0, 1, 1]
the above showing that 11 in decimal is
1
×
2
3
+
0
×
2
2
+
1
×
2
1
+
1
×
2
0
{\displaystyle 1\times 2^{3}+0\times 2^{2}+1\times 2^{1}+1\times 2^{0}}
.
Reflected this would become .1101 or
1
×
2
−
1
+
1
×
2
−
2
+
0
×
2
−
3
+
1
×
2
−
4
{\displaystyle 1\times 2^{-1}+1\times 2^{-2}+0\times 2^{-3}+1\times 2^{-4}}
Task description
Create a function/method/routine that given n, generates the n'th term of the van der Corput sequence in base 2.
Use the function to compute and display the first ten members of the sequence. (The first member of the sequence is for n=0).
As a stretch goal/extra credit, compute and show members of the sequence for bases other than 2.
See also
The Basic Low Discrepancy Sequences
Non-decimal radices/Convert
Van der Corput sequence
| #Scala | Scala | object VanDerCorput extends App {
def compute(n: Int, base: Int = 2) =
Iterator.from(0).
scanLeft(1)((a, _) => a * base).
map(b => (n - 1) / b -> b).
takeWhile(_._1 != 0).
foldLeft(0d)((a, b) => a + (b._1 % base).toDouble / b._2 / base)
val n = scala.io.StdIn.readInt
val b = scala.io.StdIn.readInt
(1 to n).foreach(x => println(compute(x, b)))
} |
http://rosettacode.org/wiki/URL_decoding | URL decoding | This task (the reverse of URL encoding and distinct from URL parser) is to provide a function
or mechanism to convert an URL-encoded string into its original unencoded form.
Test cases
The encoded string "http%3A%2F%2Ffoo%20bar%2F" should be reverted to the unencoded form "http://foo bar/".
The encoded string "google.com/search?q=%60Abdu%27l-Bah%C3%A1" should revert to the unencoded form "google.com/search?q=`Abdu'l-Bahá".
| #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref savelog symbols nobinary
url = [ -
'http%3A%2F%2Ffoo%20bar%2F', -
'mailto%3A%22Ivan%20Aim%22%20%3Civan%2Eaim%40email%2Ecom%3E', -
'%6D%61%69%6C%74%6F%3A%22%49%72%6D%61%20%55%73%65%72%22%20%3C%69%72%6D%61%2E%75%73%65%72%40%6D%61%69%6C%2E%63%6F%6D%3E' -
]
loop u_ = 0 to url.length - 1
say url[u_]
say DecodeURL(url[u_])
say
end u_
return
method DecodeURL(arg) public static
Parse arg encoded
decoded = ''
PCT = '%'
loop label e_ while encoded.length() > 0
parse encoded head (PCT) +1 code +2 tail
decoded = decoded || head
select
when code.strip('T').length() = 2 & code.datatype('X') then do
code = code.x2c()
decoded = decoded || code
end
when code.strip('T').length() \= 0 then do
decoded = decoded || PCT
tail = code || tail
end
otherwise do
nop
end
end
encoded = tail
end e_
return decoded
|
http://rosettacode.org/wiki/UPC | UPC | Goal
Convert UPC bar codes to decimal.
Specifically:
The UPC standard is actually a collection of standards -- physical standards, data format standards, product reference standards...
Here, in this task, we will focus on some of the data format standards, with an imaginary physical+electrical implementation which converts physical UPC bar codes to ASCII (with spaces and # characters representing the presence or absence of ink).
Sample input
Below, we have a representation of ten different UPC-A bar codes read by our imaginary bar code reader:
# # # ## # ## # ## ### ## ### ## #### # # # ## ## # # ## ## ### # ## ## ### # # #
# # # ## ## # #### # # ## # ## # ## # # # ### # ### ## ## ### # # ### ### # # #
# # # # # ### # # # # # # # # # # ## # ## # ## # ## # # #### ### ## # #
# # ## ## ## ## # # # # ### # ## ## # # # ## ## # ### ## ## # # #### ## # # #
# # ### ## # ## ## ### ## # ## # # ## # # ### # ## ## # # ### # ## ## # # #
# # # # ## ## # # # # ## ## # # # # # #### # ## # #### #### # # ## # #### # #
# # # ## ## # # ## ## # ### ## ## # # # # # # # # ### # # ### # # # # #
# # # # ## ## # # ## ## ### # # # # # ### ## ## ### ## ### ### ## # ## ### ## # #
# # ### ## ## # # #### # ## # #### # #### # # # # # ### # # ### # # # ### # # #
# # # #### ## # #### # # ## ## ### #### # # # # ### # ### ### # # ### # # # ### # #
Some of these were entered upside down, and one entry has a timing error.
Task
Implement code to find the corresponding decimal representation of each, rejecting the error.
Extra credit for handling the rows entered upside down (the other option is to reject them).
Notes
Each digit is represented by 7 bits:
0: 0 0 0 1 1 0 1
1: 0 0 1 1 0 0 1
2: 0 0 1 0 0 1 1
3: 0 1 1 1 1 0 1
4: 0 1 0 0 0 1 1
5: 0 1 1 0 0 0 1
6: 0 1 0 1 1 1 1
7: 0 1 1 1 0 1 1
8: 0 1 1 0 1 1 1
9: 0 0 0 1 0 1 1
On the left hand side of the bar code a space represents a 0 and a # represents a 1.
On the right hand side of the bar code, a # represents a 0 and a space represents a 1
Alternatively (for the above): spaces always represent zeros and # characters always represent ones, but the representation is logically negated -- 1s and 0s are flipped -- on the right hand side of the bar code.
The UPC-A bar code structure
It begins with at least 9 spaces (which our imaginary bar code reader unfortunately doesn't always reproduce properly),
then has a # # sequence marking the start of the sequence,
then has the six "left hand" digits,
then has a # # sequence in the middle,
then has the six "right hand digits",
then has another # # (end sequence), and finally,
then ends with nine trailing spaces (which might be eaten by wiki edits, and in any event, were not quite captured correctly by our imaginary bar code reader).
Finally, the last digit is a checksum digit which may be used to help detect errors.
Verification
Multiply each digit in the represented 12 digit sequence by the corresponding number in (3,1,3,1,3,1,3,1,3,1,3,1) and add the products.
The sum (mod 10) must be 0 (must have a zero as its last digit) if the UPC number has been read correctly.
| #Phix | Phix | with javascript_semantics
constant numbers = {" ## #", -- 0
" ## #", -- 1
" # ##", -- 2
" #### #", -- 3
" # ##", -- 4
" ## #", -- 5
" # ####", -- 6
" ### ##", -- 7
" ## ###", -- 8
" # ##"} -- 9
procedure decode(string bar_code)
bar_code = trim(bar_code)
if length(bar_code)=95
and bar_code[1..3]="# #"
and bar_code[46..50]=" # # "
and bar_code[93..95]="# #" then
for reversed=false to true do
sequence r = {}
for i=1 to 12 do
integer st = iff(i<=6?i*7-3:i*7+2)
string number = bar_code[st..st+6]
if i>6 then number = substitute_all(number," #X","X #") end if
r &= find(number,numbers)-1
end for
if not find(-1,r) then
if remainder(sum(sq_mul(r,{3,1,3,1,3,1,3,1,3,1,3,1})),10) then
printf(1,"invalid checksum\n")
else
printf(1,"%v%s\n",{r,iff(reversed?" (upside down)","")})
end if
return
end if
bar_code = reverse(bar_code)
end for
end if
printf(1,"invalid\n")
end procedure
constant bar_codes = split("""
# # # ## # ## # ## ### ## ### ## #### # # # ## ## # # ## ## ### # ## ## ### # # #
# # # ## ## # #### # # ## # ## # ## # # # ### # ### ## ## ### # # ### ### # # #
# # # # # ### # # # # # # # # # # ## # ## # ## # ## # # #### ### ## # #
# # ## ## ## ## # # # # ### # ## ## # # # ## ## # ### ## ## # # #### ## # # #
# # ### ## # ## ## ### ## # ## # # ## # # ### # ## ## # # ### # ## ## # # #
# # # # ## ## # # # # ## ## # # # # # #### # ## # #### #### # # ## # #### # #
# # # ## ## # # ## ## # ### ## ## # # # # # # # # ### # # ### # # # # #
# # # # ## ## # # ## ## ### # # # # # ### ## ## ### ## ### ### ## # ## ### ## # #
# # ### ## ## # # #### # ## # #### # #### # # # # # ### # # ### # # # ### # # #
# # # #### ## # #### # # ## ## ### #### # # # # ### # ### ### # # ### # # # ### # #
""","\n",true)
for i=1 to length(bar_codes) do
decode(bar_codes[i])
end for
|
http://rosettacode.org/wiki/Update_a_configuration_file | Update a configuration file | We have a configuration file as follows:
# This is a configuration file in standard configuration file format
#
# Lines begininning with a hash or a semicolon are ignored by the application
# program. Blank lines are also ignored by the application program.
# The first word on each non comment line is the configuration option.
# Remaining words or numbers on the line are configuration parameter
# data fields.
# Note that configuration option names are not case sensitive. However,
# configuration parameter data is case sensitive and the lettercase must
# be preserved.
# This is a favourite fruit
FAVOURITEFRUIT banana
# This is a boolean that should be set
NEEDSPEELING
# This boolean is commented out
; SEEDSREMOVED
# How many bananas we have
NUMBEROFBANANAS 48
The task is to manipulate the configuration file as follows:
Disable the needspeeling option (using a semicolon prefix)
Enable the seedsremoved option by removing the semicolon and any leading whitespace
Change the numberofbananas parameter to 1024
Enable (or create if it does not exist in the file) a parameter for numberofstrawberries with a value of 62000
Note that configuration option names are not case sensitive. This means that changes should be effected, regardless of the case.
Options should always be disabled by prefixing them with a semicolon.
Lines beginning with hash symbols should not be manipulated and left unchanged in the revised file.
If a configuration option does not exist within the file (in either enabled or disabled form), it should be added during this update. Duplicate configuration option names in the file should be removed, leaving just the first entry.
For the purpose of this task, the revised file should contain appropriate entries, whether enabled or not for needspeeling,seedsremoved,numberofbananas and numberofstrawberries.)
The update should rewrite configuration option names in capital letters. However lines beginning with hashes and any parameter data must not be altered (eg the banana for favourite fruit must not become capitalized). The update process should also replace double semicolon prefixes with just a single semicolon (unless it is uncommenting the option, in which case it should remove all leading semicolons).
Any lines beginning with a semicolon or groups of semicolons, but no following option should be removed, as should any leading or trailing whitespace on the lines. Whitespace between the option and parameters should consist only of a single
space, and any non-ASCII extended characters, tabs characters, or control codes
(other than end of line markers), should also be removed.
Related tasks
Read a configuration file
| #Ruby | Ruby | require 'stringio'
class ConfigFile
# create a ConfigFile object from a file
def self.file(filename)
fh = File.open(filename)
obj = self.new(fh)
obj.filename = filename
fh.close
obj
end
# create a ConfigFile object from a string
def self.data(string)
fh = StringIO.new(string)
obj = self.new(fh)
fh.close
obj
end
def initialize(filehandle)
@lines = filehandle.readlines
@filename = nil
tidy_file
end
attr :filename
def save()
if @filename
File.open(@filename, "w") {|f| f.write(self)}
end
end
def tidy_file()
@lines.map! do |line|
# remove leading whitespace
line.lstrip!
if line.match(/^#/)
# Lines beginning with hash symbols should not be manipulated and left
# unchanged in the revised file.
line
else
# replace double semicolon prefixes with just a single semicolon
line.sub!(/^;+\s+/, "; ")
if line.match(/^; \s*$/)
# Any lines beginning with a semicolon or groups of semicolons, but no
# following option should be removed
line = ""
else
# remove ... any trailing whitespace on the lines
line = line.rstrip + "\n"
# Whitespace between the option and paramters should consist only of a
# single space
if m = line.match(/^(; )?([[:upper:]]+)\s+(.*)/)
line = (m[1].nil? ? "" : m[1]) + format_line(m[2], m[3])
end
end
line
end
end
end
def format_line(option, value)
"%s%s\n" % [option.upcase.strip, value.nil? ? "" : " " + value.to_s.strip]
end
# returns the index of the option, or nil if not found
def find_option(option)
@lines.find_index {|line| line.match(/^#{option.upcase.strip}\b/)}
end
# uncomments a disabled option
def enable_option(option)
if idx = find_option("; " + option)
@lines[idx][/^; /] = ""
end
end
# comment a line with a semi-colon
def disable_option(option)
if idx = find_option(option)
@lines[idx][/^/] = "; "
end
end
# add an option, or change the value of an existing option.
# use nil for the value to set a boolean option
def set_value(option, value)
if idx = find_option(option)
@lines[idx] = format_line(option, value)
else
@lines << format_line(option, value)
end
end
def to_s
@lines.join('')
end
end
config = ConfigFile.data(DATA.read)
config.disable_option('needspeeling')
config.enable_option('seedsremoved')
config.set_value('numberofbananas', 1024)
config.set_value('numberofstrawberries', 62000)
puts config
__END__
# This is a configuration file in standard configuration file format
#
# Lines begininning with a hash or a semicolon are ignored by the application
# program. Blank lines are also ignored by the application program.
# The first word on each non comment line is the configuration option.
# Remaining words or numbers on the line are configuration parameter
# data fields.
# Note that configuration option names are not case sensitive. However,
# configuration parameter data is case sensitive and the lettercase must
# be preserved.
# This is a favourite fruit
FAVOURITEFRUIT banana
# This is a boolean that should be set
NEEDSPEELING
# This boolean is commented out
;;; SEEDSREMOVED
;;;
# How many bananas we have
NUMBEROFBANANAS 48 |
http://rosettacode.org/wiki/User_input/Text | User input/Text | User input/Text is part of Short Circuit's Console Program Basics selection.
Task
Input a string and the integer 75000 from the text console.
See also: User input/Graphical
| #JavaScript | JavaScript | WScript.Echo("Enter a string");
var str = WScript.StdIn.ReadLine();
var val = 0;
while (val != 75000) {
WScript.Echo("Enter the integer 75000");
val = parseInt( WScript.StdIn.ReadLine() );
} |
http://rosettacode.org/wiki/User_input/Text | User input/Text | User input/Text is part of Short Circuit's Console Program Basics selection.
Task
Input a string and the integer 75000 from the text console.
See also: User input/Graphical
| #Joy | Joy |
"Enter a string: " putchars
stdin fgets
"Enter a number: " putchars
stdin fgets 10 strtol.
|
http://rosettacode.org/wiki/User_input/Graphical | User input/Graphical |
In this task, the goal is to input a string and the integer 75000, from graphical user interface.
See also: User input/Text
| #PicoLisp | PicoLisp | (and
(call 'sh "-c"
(pack
"dialog \
--inputbox 'Input a string' 8 60 \
--inputbox 'Input a number' 8 20 \
2>"
(tmp "dlg") ) )
(split (in (tmp "dlg") (line)) "^I")
(cons (pack (car @)) (format (cadr @))) ) |
http://rosettacode.org/wiki/User_input/Graphical | User input/Graphical |
In this task, the goal is to input a string and the integer 75000, from graphical user interface.
See also: User input/Text
| #PowerBASIC | PowerBASIC | FUNCTION PBMAIN () AS LONG
result$ = INPUTBOX$("Enter a string.")
MSGBOX result$
DO
'This assumes that 75000 is the ONLY valid input.
result$ = INPUTBOX$("Enter the number 75000.")
IF VAL(result$) <> 75000 THEN
MSGBOX "You need to enter 75000!"
ELSE
MSGBOX "You entered the right number."
EXIT DO
END IF
LOOP
END FUNCTION |
http://rosettacode.org/wiki/UTF-8_encode_and_decode | UTF-8 encode and decode | As described in UTF-8 and in Wikipedia, UTF-8 is a popular encoding of (multi-byte) Unicode code-points into eight-bit octets.
The goal of this task is to write a encoder that takes a unicode code-point (an integer representing a unicode character) and returns a sequence of 1-4 bytes representing that character in the UTF-8 encoding.
Then you have to write the corresponding decoder that takes a sequence of 1-4 UTF-8 encoded bytes and return the corresponding unicode character.
Demonstrate the functionality of your encoder and decoder on the following five characters:
Character Name Unicode UTF-8 encoding (hex)
---------------------------------------------------------------------------------
A LATIN CAPITAL LETTER A U+0041 41
ö LATIN SMALL LETTER O WITH DIAERESIS U+00F6 C3 B6
Ж CYRILLIC CAPITAL LETTER ZHE U+0416 D0 96
€ EURO SIGN U+20AC E2 82 AC
𝄞 MUSICAL SYMBOL G CLEF U+1D11E F0 9D 84 9E
Provided below is a reference implementation in Common Lisp.
| #Ruby | Ruby |
character_arr = ["A","ö","Ж","€","𝄞"]
for c in character_arr do
puts "Character: " + c.encode("utf-8")
puts "Code-Point: #{c.encode("utf-8").ord.to_s(16).upcase}"
puts "Code-Units: " + c.each_byte.map { |n| '%02X ' % (n & 0xFF) }.join
puts ""
end
|
http://rosettacode.org/wiki/UTF-8_encode_and_decode | UTF-8 encode and decode | As described in UTF-8 and in Wikipedia, UTF-8 is a popular encoding of (multi-byte) Unicode code-points into eight-bit octets.
The goal of this task is to write a encoder that takes a unicode code-point (an integer representing a unicode character) and returns a sequence of 1-4 bytes representing that character in the UTF-8 encoding.
Then you have to write the corresponding decoder that takes a sequence of 1-4 UTF-8 encoded bytes and return the corresponding unicode character.
Demonstrate the functionality of your encoder and decoder on the following five characters:
Character Name Unicode UTF-8 encoding (hex)
---------------------------------------------------------------------------------
A LATIN CAPITAL LETTER A U+0041 41
ö LATIN SMALL LETTER O WITH DIAERESIS U+00F6 C3 B6
Ж CYRILLIC CAPITAL LETTER ZHE U+0416 D0 96
€ EURO SIGN U+20AC E2 82 AC
𝄞 MUSICAL SYMBOL G CLEF U+1D11E F0 9D 84 9E
Provided below is a reference implementation in Common Lisp.
| #Rust | Rust | fn main() {
let chars = vec!('A', 'ö', 'Ж', '€', '𝄞');
chars.iter().for_each(|c| {
let mut encoded = vec![0; c.len_utf8()];
c.encode_utf8(&mut encoded);
let decoded = String::from_utf8(encoded.to_vec()).unwrap();
let encoded_string = encoded.iter().fold(String::new(), |acc, val| format!("{}{:X}", acc, val));
println!("Character: {}, Unicode:{}, UTF-8 encoded:{}, Decoded: {}", c, c.escape_unicode(), encoded_string , decoded);
});
}
|
http://rosettacode.org/wiki/URL_encoding | URL encoding | Task
Provide a function or mechanism to convert a provided string into URL encoding representation.
In URL encoding, special characters, control characters and extended characters
are converted into a percent symbol followed by a two digit hexadecimal code,
So a space character encodes into %20 within the string.
For the purposes of this task, every character except 0-9, A-Z and a-z requires conversion, so the following characters all require conversion by default:
ASCII control codes (Character ranges 00-1F hex (0-31 decimal) and 7F (127 decimal).
ASCII symbols (Character ranges 32-47 decimal (20-2F hex))
ASCII symbols (Character ranges 58-64 decimal (3A-40 hex))
ASCII symbols (Character ranges 91-96 decimal (5B-60 hex))
ASCII symbols (Character ranges 123-126 decimal (7B-7E hex))
Extended characters with character codes of 128 decimal (80 hex) and above.
Example
The string "http://foo bar/" would be encoded as "http%3A%2F%2Ffoo%20bar%2F".
Variations
Lowercase escapes are legal, as in "http%3a%2f%2ffoo%20bar%2f".
Some standards give different rules: RFC 3986, Uniform Resource Identifier (URI): Generic Syntax, section 2.3, says that "-._~" should not be encoded. HTML 5, section 4.10.22.5 URL-encoded form data, says to preserve "-._*", and to encode space " " to "+". The options below provide for utilization of an exception string, enabling preservation (non encoding) of particular characters to meet specific standards.
Options
It is permissible to use an exception string (containing a set of symbols
that do not need to be converted).
However, this is an optional feature and is not a requirement of this task.
Related tasks
URL decoding
URL parser
| #ooRexx | ooRexx | sub urlencode {
my $s = shift;
$s =~ s/([^-A-Za-z0-9_.!~*'() ])/sprintf("%%%02X", ord($1))/eg;
$s =~ tr/ /+/;
return $s;
}
print urlencode('http://foo bar/')."\n";
|
http://rosettacode.org/wiki/URL_encoding | URL encoding | Task
Provide a function or mechanism to convert a provided string into URL encoding representation.
In URL encoding, special characters, control characters and extended characters
are converted into a percent symbol followed by a two digit hexadecimal code,
So a space character encodes into %20 within the string.
For the purposes of this task, every character except 0-9, A-Z and a-z requires conversion, so the following characters all require conversion by default:
ASCII control codes (Character ranges 00-1F hex (0-31 decimal) and 7F (127 decimal).
ASCII symbols (Character ranges 32-47 decimal (20-2F hex))
ASCII symbols (Character ranges 58-64 decimal (3A-40 hex))
ASCII symbols (Character ranges 91-96 decimal (5B-60 hex))
ASCII symbols (Character ranges 123-126 decimal (7B-7E hex))
Extended characters with character codes of 128 decimal (80 hex) and above.
Example
The string "http://foo bar/" would be encoded as "http%3A%2F%2Ffoo%20bar%2F".
Variations
Lowercase escapes are legal, as in "http%3a%2f%2ffoo%20bar%2f".
Some standards give different rules: RFC 3986, Uniform Resource Identifier (URI): Generic Syntax, section 2.3, says that "-._~" should not be encoded. HTML 5, section 4.10.22.5 URL-encoded form data, says to preserve "-._*", and to encode space " " to "+". The options below provide for utilization of an exception string, enabling preservation (non encoding) of particular characters to meet specific standards.
Options
It is permissible to use an exception string (containing a set of symbols
that do not need to be converted).
However, this is an optional feature and is not a requirement of this task.
Related tasks
URL decoding
URL parser
| #Perl | Perl | sub urlencode {
my $s = shift;
$s =~ s/([^-A-Za-z0-9_.!~*'() ])/sprintf("%%%02X", ord($1))/eg;
$s =~ tr/ /+/;
return $s;
}
print urlencode('http://foo bar/')."\n";
|
http://rosettacode.org/wiki/Variables | Variables | Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| #Lingo | Lingo | x = 23
y = "Hello world!"
z = TRUE -- same effect as z = 1 |
http://rosettacode.org/wiki/Variables | Variables | Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| #Logo | Logo | make "g1 0
name 2 "g2 ; same as make with parameters reversed
global "g3 ; no initial value
to func :x
make "g4 4 ; still global
localmake "L1 6
local ["L2 "L3] ; local variables, collection syntax
func2 :g4
print :L2 ; 9, modified by func2
print :L3 ; L3 has no value, was not modified by func2
end
to func2 :y
make "g3 :y
make "L2 :L1 + 3 ; dynamic scope: can see variables of callers
localmake "L3 5 ; locally override L3 from caller
(print :y :L1 :L2 :L3) ; 4 6 9 5
end
print :g4 ; 4
print :L1 ; L1 has no value
print name? "L1 ; false, L1 is not bound in the current scope |
http://rosettacode.org/wiki/Van_Eck_sequence | Van Eck sequence | The sequence is generated by following this pseudo-code:
A: The first term is zero.
Repeatedly apply:
If the last term is *new* to the sequence so far then:
B: The next term is zero.
Otherwise:
C: The next term is how far back this last term occured previously.
Example
Using A:
0
Using B:
0 0
Using C:
0 0 1
Using B:
0 0 1 0
Using C: (zero last occurred two steps back - before the one)
0 0 1 0 2
Using B:
0 0 1 0 2 0
Using C: (two last occurred two steps back - before the zero)
0 0 1 0 2 0 2 2
Using C: (two last occurred one step back)
0 0 1 0 2 0 2 2 1
Using C: (one last appeared six steps back)
0 0 1 0 2 0 2 2 1 6
...
Task
Create a function/procedure/method/subroutine/... to generate the Van Eck sequence of numbers.
Use it to display here, on this page:
The first ten terms of the sequence.
Terms 991 - to - 1000 of the sequence.
References
Don't Know (the Van Eck Sequence) - Numberphile video.
Wikipedia Article: Van Eck's Sequence.
OEIS sequence: A181391.
| #Visual_Basic_.NET | Visual Basic .NET | Imports System.Linq
Module Module1
Dim h() As Integer
Sub sho(i As Integer)
Console.WriteLine(String.Join(" ", h.Skip(i).Take(10)))
End Sub
Sub Main()
Dim a, b, c, d, f, g As Integer : g = 1000
h = new Integer(g){} : a = 0 : b = 1 : For c = 2 To g
f = h(b) : For d = a To 0 Step -1
If f = h(d) Then h(c) = b - d: Exit For
Next : a = b : b = c : Next : sho(0) : sho(990)
End Sub
End Module |
http://rosettacode.org/wiki/Van_Eck_sequence | Van Eck sequence | The sequence is generated by following this pseudo-code:
A: The first term is zero.
Repeatedly apply:
If the last term is *new* to the sequence so far then:
B: The next term is zero.
Otherwise:
C: The next term is how far back this last term occured previously.
Example
Using A:
0
Using B:
0 0
Using C:
0 0 1
Using B:
0 0 1 0
Using C: (zero last occurred two steps back - before the one)
0 0 1 0 2
Using B:
0 0 1 0 2 0
Using C: (two last occurred two steps back - before the zero)
0 0 1 0 2 0 2 2
Using C: (two last occurred one step back)
0 0 1 0 2 0 2 2 1
Using C: (one last appeared six steps back)
0 0 1 0 2 0 2 2 1 6
...
Task
Create a function/procedure/method/subroutine/... to generate the Van Eck sequence of numbers.
Use it to display here, on this page:
The first ten terms of the sequence.
Terms 991 - to - 1000 of the sequence.
References
Don't Know (the Van Eck Sequence) - Numberphile video.
Wikipedia Article: Van Eck's Sequence.
OEIS sequence: A181391.
| #Vlang | Vlang | fn main() {
max := 1000
mut a := []int{len: max} // all zero by default
for n in 0..max-1 {
for m := n - 1; m >= 0; m-- {
if a[m] == a[n] {
a[n+1] = n - m
break
}
}
}
println("The first ten terms of the Van Eck sequence are:")
println(a[..10])
println("\nTerms 991 to 1000 of the sequence are:")
println(a[990..])
} |
http://rosettacode.org/wiki/Variadic_function | Variadic function | Task
Create a function which takes in a variable number of arguments and prints each one on its own line.
Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime.
Functions of this type are also known as Variadic Functions.
Related task
Call a function
| #Slate | Slate | define: #printAll -> [| *rest | rest do: [| :arg | inform: arg printString]].
printAll applyTo: #(4 3 5 6 4 3).
printAll applyTo: #('Rosetta' 'Code' 'Is' 'Awesome!'). |
http://rosettacode.org/wiki/Variadic_function | Variadic function | Task
Create a function which takes in a variable number of arguments and prints each one on its own line.
Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime.
Functions of this type are also known as Variadic Functions.
Related task
Call a function
| #Swift | Swift | func printAll<T>(things: T...) {
// "things" is a [T]
for i in things {
print(i)
}
} |
http://rosettacode.org/wiki/Variadic_function | Variadic function | Task
Create a function which takes in a variable number of arguments and prints each one on its own line.
Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime.
Functions of this type are also known as Variadic Functions.
Related task
Call a function
| #Tcl | Tcl | proc print_all {args} {puts [join $args \n]}
print_all 4 3 5 6 4 3
print_all 4 3 5
print_all Rosetta Code Is Awesome!
set things {Rosetta Code Is Awesome!}
print_all $things ;# ==> incorrect: passes a single argument (a list) to print_all
print_all {*}$things ;# ==> correct: passes each element of the list to the procedure |
http://rosettacode.org/wiki/Vector_products | Vector products | A vector is defined as having three dimensions as being represented by an ordered collection of three numbers: (X, Y, Z).
If you imagine a graph with the x and y axis being at right angles to each other and having a third, z axis coming out of the page, then a triplet of numbers, (X, Y, Z) would represent a point in the region, and a vector from the origin to the point.
Given the vectors:
A = (a1, a2, a3)
B = (b1, b2, b3)
C = (c1, c2, c3)
then the following common vector products are defined:
The dot product (a scalar quantity)
A • B = a1b1 + a2b2 + a3b3
The cross product (a vector quantity)
A x B = (a2b3 - a3b2, a3b1 - a1b3, a1b2 - a2b1)
The scalar triple product (a scalar quantity)
A • (B x C)
The vector triple product (a vector quantity)
A x (B x C)
Task
Given the three vectors:
a = ( 3, 4, 5)
b = ( 4, 3, 5)
c = (-5, -12, -13)
Create a named function/subroutine/method to compute the dot product of two vectors.
Create a function to compute the cross product of two vectors.
Optionally create a function to compute the scalar triple product of three vectors.
Optionally create a function to compute the vector triple product of three vectors.
Compute and display: a • b
Compute and display: a x b
Compute and display: a • (b x c), the scalar triple product.
Compute and display: a x (b x c), the vector triple product.
References
A starting page on Wolfram MathWorld is Vector Multiplication .
Wikipedia dot product.
Wikipedia cross product.
Wikipedia triple product.
Related tasks
Dot product
Quaternion type
| #jq | jq | def dot_product(a; b):
reduce range(0;a|length) as $i (0; . + (a[$i] * b[$i]) );
# for 3d vectors
def cross_product(a;b):
[ a[1]*b[2] - a[2]*b[1], a[2]*b[0] - a[0]*b[2], a[0]*b[1]-a[1]*b[0] ];
def scalar_triple_product(a;b;c):
dot_product(a; cross_product(b; c));
def vector_triple_product(a;b;c):
cross_product(a; cross_product(b; c));
def main:
[3, 4, 5] as $a
| [4, 3, 5] as $b
| [-5, -12, -13] as $c
| "a . b = \(dot_product($a; $b))",
"a x b = [\( cross_product($a; $b) | map(tostring) | join (", ") )]" ,
"a . (b x c) = \( scalar_triple_product ($a; $b; $c)) )",
"a x (b x c) = [\( vector_triple_product($a; $b; $c)|map(tostring)|join (", ") )]" ; |
http://rosettacode.org/wiki/Validate_International_Securities_Identification_Number | Validate International Securities Identification Number | An International Securities Identification Number (ISIN) is a unique international identifier for a financial security such as a stock or bond.
Task
Write a function or program that takes a string as input, and checks whether it is a valid ISIN.
It is only valid if it has the correct format, and the embedded checksum is correct.
Demonstrate that your code passes the test-cases listed below.
Details
The format of an ISIN is as follows:
┌───────────── a 2-character ISO country code (A-Z)
│ ┌─────────── a 9-character security code (A-Z, 0-9)
│ │ ┌── a checksum digit (0-9)
AU0000XVGZA3
For this task, you may assume that any 2-character alphabetic sequence is a valid country code.
The checksum can be validated as follows:
Replace letters with digits, by converting each character from base 36 to base 10, e.g. AU0000XVGZA3 →1030000033311635103.
Perform the Luhn test on this base-10 number.
There is a separate task for this test: Luhn test of credit card numbers.
You don't have to replicate the implementation of this test here ─── you can just call the existing function from that task. (Add a comment stating if you did this.)
Test cases
ISIN
Validity
Comment
US0378331005
valid
US0373831005
not valid
The transposition typo is caught by the checksum constraint.
U50378331005
not valid
The substitution typo is caught by the format constraint.
US03378331005
not valid
The duplication typo is caught by the format constraint.
AU0000XVGZA3
valid
AU0000VXGZA3
valid
Unfortunately, not all transposition typos are caught by the checksum constraint.
FR0000988040
valid
(The comments are just informational. Your function should simply return a Boolean result. See #Raku for a reference solution.)
Related task:
Luhn test of credit card numbers
Also see
Interactive online ISIN validator
Wikipedia article: International Securities Identification Number
| #Vlang | Vlang | import regex
const (
inc = [
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
[0, 2, 4, 6, 8, 1, 3, 5, 7, 9],
]
)
fn valid_isin(n string) bool {
mut r,_,_ := regex.regex_base('^[A-Z]{2}[A-Z0-9]{9}\d$')
if !r.matches_string(n) {
return false
}
mut sum := 0
mut p := 0
for i := 10; i >= 0; i-- {
p = 1 - p
mut d := n[i..i+1].int()
if d < 'A'.int() {
sum += inc[p][d-'0'.int()]
} else {
d -= 'A'.int()
sum += inc[p][d%10]
p = 1 - p
sum += inc[p][d/10+1]
}
}
sum += n[11..12].int() - '0'.int()
return sum%10 == 0
}
struct Testcases {
isin string
valid bool
}
fn main(){
testcases := [
Testcases{"US0378331005", true},
Testcases{"US0373831005", false},
Testcases{"U50378331005", false},
Testcases{"US03378331005", false},
Testcases{"AU0000XVGZA3", true},
Testcases{"AU0000VXGZA3", true},
Testcases{"FR0000988040", true},
]
for testcase in testcases {
actual := valid_isin(testcase.isin)
if actual != testcase.valid {
println("expected ${testcase.valid} for ${testcase.isin}, got $actual")
}
}
} |
http://rosettacode.org/wiki/Validate_International_Securities_Identification_Number | Validate International Securities Identification Number | An International Securities Identification Number (ISIN) is a unique international identifier for a financial security such as a stock or bond.
Task
Write a function or program that takes a string as input, and checks whether it is a valid ISIN.
It is only valid if it has the correct format, and the embedded checksum is correct.
Demonstrate that your code passes the test-cases listed below.
Details
The format of an ISIN is as follows:
┌───────────── a 2-character ISO country code (A-Z)
│ ┌─────────── a 9-character security code (A-Z, 0-9)
│ │ ┌── a checksum digit (0-9)
AU0000XVGZA3
For this task, you may assume that any 2-character alphabetic sequence is a valid country code.
The checksum can be validated as follows:
Replace letters with digits, by converting each character from base 36 to base 10, e.g. AU0000XVGZA3 →1030000033311635103.
Perform the Luhn test on this base-10 number.
There is a separate task for this test: Luhn test of credit card numbers.
You don't have to replicate the implementation of this test here ─── you can just call the existing function from that task. (Add a comment stating if you did this.)
Test cases
ISIN
Validity
Comment
US0378331005
valid
US0373831005
not valid
The transposition typo is caught by the checksum constraint.
U50378331005
not valid
The substitution typo is caught by the format constraint.
US03378331005
not valid
The duplication typo is caught by the format constraint.
AU0000XVGZA3
valid
AU0000VXGZA3
valid
Unfortunately, not all transposition typos are caught by the checksum constraint.
FR0000988040
valid
(The comments are just informational. Your function should simply return a Boolean result. See #Raku for a reference solution.)
Related task:
Luhn test of credit card numbers
Also see
Interactive online ISIN validator
Wikipedia article: International Securities Identification Number
| #Wren | Wren | import "/str" for Char
import "/trait" for Stepped
import "/fmt" for Conv, Fmt
var luhn = Fn.new { |s|
s = s[-1..0]
var s1 = Stepped.new(s, 2).reduce(0) { |sum, d| sum + d.bytes[0] - 48 }
var s2 = Stepped.new(s[1..-1], 2).reduce(0) { |sum, d|
var d2 = (d.bytes[0] - 48) * 2
return sum + ((d2 > 9) ? d2%10 + 1 : d2)
}
return (s1 + s2)%10 == 0
}
var isin = Fn.new { |s|
if (!(s is String && s.count == 12)) return false
for (i in 0..11) {
var c = s[i]
if (i <= 1) {
if (!Char.isUpper(c)) return false
} else if (i >= 2 && i <= 10) {
if (!Char.isUpper(c) && !Char.isDigit(c)) return false
} else {
if (!Char.isDigit(c)) return false
}
}
var dec = ""
for (i in 0...s.count) dec = dec + "%(Conv.atoi(s[i], 36))"
return luhn.call(dec)
}
var tests = [
"US0378331005", "US0373831005", "U50378331005", "US03378331005",
"AU0000XVGZA3", "AU0000VXGZA3", "FR0000988040"
]
for (test in tests) {
var ans = (isin.call(test)) ? "valid" : "not valid"
System.print("%(Fmt.s(-13, test)) -> %(ans)")
} |
http://rosettacode.org/wiki/Van_der_Corput_sequence | Van der Corput sequence | When counting integers in binary, if you put a (binary) point to the righEasyLangt of the count then the column immediately to the left denotes a digit with a multiplier of
2
0
{\displaystyle 2^{0}}
; the digit in the next column to the left has a multiplier of
2
1
{\displaystyle 2^{1}}
; and so on.
So in the following table:
0.
1.
10.
11.
...
the binary number "10" is
1
×
2
1
+
0
×
2
0
{\displaystyle 1\times 2^{1}+0\times 2^{0}}
.
You can also have binary digits to the right of the “point”, just as in the decimal number system. In that case, the digit in the place immediately to the right of the point has a weight of
2
−
1
{\displaystyle 2^{-1}}
, or
1
/
2
{\displaystyle 1/2}
.
The weight for the second column to the right of the point is
2
−
2
{\displaystyle 2^{-2}}
or
1
/
4
{\displaystyle 1/4}
. And so on.
If you take the integer binary count of the first table, and reflect the digits about the binary point, you end up with the van der Corput sequence of numbers in base 2.
.0
.1
.01
.11
...
The third member of the sequence, binary 0.01, is therefore
0
×
2
−
1
+
1
×
2
−
2
{\displaystyle 0\times 2^{-1}+1\times 2^{-2}}
or
1
/
4
{\displaystyle 1/4}
.
Distribution of 2500 points each: Van der Corput (top) vs pseudorandom
0
≤
x
<
1
{\displaystyle 0\leq x<1}
Monte Carlo simulations
This sequence is also a superset of the numbers representable by the "fraction" field of an old IEEE floating point standard. In that standard, the "fraction" field represented the fractional part of a binary number beginning with "1." e.g. 1.101001101.
Hint
A hint at a way to generate members of the sequence is to modify a routine used to change the base of an integer:
>>> def base10change(n, base):
digits = []
while n:
n,remainder = divmod(n, base)
digits.insert(0, remainder)
return digits
>>> base10change(11, 2)
[1, 0, 1, 1]
the above showing that 11 in decimal is
1
×
2
3
+
0
×
2
2
+
1
×
2
1
+
1
×
2
0
{\displaystyle 1\times 2^{3}+0\times 2^{2}+1\times 2^{1}+1\times 2^{0}}
.
Reflected this would become .1101 or
1
×
2
−
1
+
1
×
2
−
2
+
0
×
2
−
3
+
1
×
2
−
4
{\displaystyle 1\times 2^{-1}+1\times 2^{-2}+0\times 2^{-3}+1\times 2^{-4}}
Task description
Create a function/method/routine that given n, generates the n'th term of the van der Corput sequence in base 2.
Use the function to compute and display the first ten members of the sequence. (The first member of the sequence is for n=0).
As a stretch goal/extra credit, compute and show members of the sequence for bases other than 2.
See also
The Basic Low Discrepancy Sequences
Non-decimal radices/Convert
Van der Corput sequence
| #Seed7 | Seed7 | $ include "seed7_05.s7i";
include "float.s7i";
const func float: vdc (in var integer: number, in integer: base) is func
result
var float: vdc is 0.0;
local
var integer: denom is 1;
var integer: remainder is 0;
begin
while number <> 0 do
denom *:= base;
remainder := number rem base;
number := number div base;
vdc +:= flt(remainder) / flt(denom);
end while;
end func;
const proc: main is func
local
var integer: base is 0;
var integer: number is 0;
begin
for base range 2 to 5 do
writeln;
writeln("Base " <& base);
for number range 0 to 9 do
write(vdc(number, base) digits 6 <& " ");
end for;
writeln;
end for;
end func; |
http://rosettacode.org/wiki/Van_der_Corput_sequence | Van der Corput sequence | When counting integers in binary, if you put a (binary) point to the righEasyLangt of the count then the column immediately to the left denotes a digit with a multiplier of
2
0
{\displaystyle 2^{0}}
; the digit in the next column to the left has a multiplier of
2
1
{\displaystyle 2^{1}}
; and so on.
So in the following table:
0.
1.
10.
11.
...
the binary number "10" is
1
×
2
1
+
0
×
2
0
{\displaystyle 1\times 2^{1}+0\times 2^{0}}
.
You can also have binary digits to the right of the “point”, just as in the decimal number system. In that case, the digit in the place immediately to the right of the point has a weight of
2
−
1
{\displaystyle 2^{-1}}
, or
1
/
2
{\displaystyle 1/2}
.
The weight for the second column to the right of the point is
2
−
2
{\displaystyle 2^{-2}}
or
1
/
4
{\displaystyle 1/4}
. And so on.
If you take the integer binary count of the first table, and reflect the digits about the binary point, you end up with the van der Corput sequence of numbers in base 2.
.0
.1
.01
.11
...
The third member of the sequence, binary 0.01, is therefore
0
×
2
−
1
+
1
×
2
−
2
{\displaystyle 0\times 2^{-1}+1\times 2^{-2}}
or
1
/
4
{\displaystyle 1/4}
.
Distribution of 2500 points each: Van der Corput (top) vs pseudorandom
0
≤
x
<
1
{\displaystyle 0\leq x<1}
Monte Carlo simulations
This sequence is also a superset of the numbers representable by the "fraction" field of an old IEEE floating point standard. In that standard, the "fraction" field represented the fractional part of a binary number beginning with "1." e.g. 1.101001101.
Hint
A hint at a way to generate members of the sequence is to modify a routine used to change the base of an integer:
>>> def base10change(n, base):
digits = []
while n:
n,remainder = divmod(n, base)
digits.insert(0, remainder)
return digits
>>> base10change(11, 2)
[1, 0, 1, 1]
the above showing that 11 in decimal is
1
×
2
3
+
0
×
2
2
+
1
×
2
1
+
1
×
2
0
{\displaystyle 1\times 2^{3}+0\times 2^{2}+1\times 2^{1}+1\times 2^{0}}
.
Reflected this would become .1101 or
1
×
2
−
1
+
1
×
2
−
2
+
0
×
2
−
3
+
1
×
2
−
4
{\displaystyle 1\times 2^{-1}+1\times 2^{-2}+0\times 2^{-3}+1\times 2^{-4}}
Task description
Create a function/method/routine that given n, generates the n'th term of the van der Corput sequence in base 2.
Use the function to compute and display the first ten members of the sequence. (The first member of the sequence is for n=0).
As a stretch goal/extra credit, compute and show members of the sequence for bases other than 2.
See also
The Basic Low Discrepancy Sequences
Non-decimal radices/Convert
Van der Corput sequence
| #Sidef | Sidef | func vdc(value, base=2) {
while (value[-1] > 0) {
value.append(value[-1] / base -> int)
}
var (x, sum) = (1, 0)
value.each { |i|
sum += ((i % base) / (x *= base))
}
return sum
}
for base in (2..5) {
var seq = 10.of {|i| vdc([i], base) }
"base %d: %s\n".printf(base, seq.map{|n| "%.4f" % n}.join(', '))
} |
http://rosettacode.org/wiki/URL_decoding | URL decoding | This task (the reverse of URL encoding and distinct from URL parser) is to provide a function
or mechanism to convert an URL-encoded string into its original unencoded form.
Test cases
The encoded string "http%3A%2F%2Ffoo%20bar%2F" should be reverted to the unencoded form "http://foo bar/".
The encoded string "google.com/search?q=%60Abdu%27l-Bah%C3%A1" should revert to the unencoded form "google.com/search?q=`Abdu'l-Bahá".
| #NewLISP | NewLISP | ;; universal decoder, works for ASCII and UTF-8
;; (source http://www.newlisp.org/index.cgi?page=Code_Snippets)
(define (url-decode url (opt nil))
(if opt (replace "+" url " "))
(replace "%([0-9a-f][0-9a-f])" url (pack "b" (int $1 0 16)) 1))
(url-decode "http%3A%2F%2Ffoo%20bar%2F") |
http://rosettacode.org/wiki/URL_decoding | URL decoding | This task (the reverse of URL encoding and distinct from URL parser) is to provide a function
or mechanism to convert an URL-encoded string into its original unencoded form.
Test cases
The encoded string "http%3A%2F%2Ffoo%20bar%2F" should be reverted to the unencoded form "http://foo bar/".
The encoded string "google.com/search?q=%60Abdu%27l-Bah%C3%A1" should revert to the unencoded form "google.com/search?q=`Abdu'l-Bahá".
| #Nim | Nim | import cgi
echo decodeUrl("http%3A%2F%2Ffoo%20bar%2F") |
http://rosettacode.org/wiki/UPC | UPC | Goal
Convert UPC bar codes to decimal.
Specifically:
The UPC standard is actually a collection of standards -- physical standards, data format standards, product reference standards...
Here, in this task, we will focus on some of the data format standards, with an imaginary physical+electrical implementation which converts physical UPC bar codes to ASCII (with spaces and # characters representing the presence or absence of ink).
Sample input
Below, we have a representation of ten different UPC-A bar codes read by our imaginary bar code reader:
# # # ## # ## # ## ### ## ### ## #### # # # ## ## # # ## ## ### # ## ## ### # # #
# # # ## ## # #### # # ## # ## # ## # # # ### # ### ## ## ### # # ### ### # # #
# # # # # ### # # # # # # # # # # ## # ## # ## # ## # # #### ### ## # #
# # ## ## ## ## # # # # ### # ## ## # # # ## ## # ### ## ## # # #### ## # # #
# # ### ## # ## ## ### ## # ## # # ## # # ### # ## ## # # ### # ## ## # # #
# # # # ## ## # # # # ## ## # # # # # #### # ## # #### #### # # ## # #### # #
# # # ## ## # # ## ## # ### ## ## # # # # # # # # ### # # ### # # # # #
# # # # ## ## # # ## ## ### # # # # # ### ## ## ### ## ### ### ## # ## ### ## # #
# # ### ## ## # # #### # ## # #### # #### # # # # # ### # # ### # # # ### # # #
# # # #### ## # #### # # ## ## ### #### # # # # ### # ### ### # # ### # # # ### # #
Some of these were entered upside down, and one entry has a timing error.
Task
Implement code to find the corresponding decimal representation of each, rejecting the error.
Extra credit for handling the rows entered upside down (the other option is to reject them).
Notes
Each digit is represented by 7 bits:
0: 0 0 0 1 1 0 1
1: 0 0 1 1 0 0 1
2: 0 0 1 0 0 1 1
3: 0 1 1 1 1 0 1
4: 0 1 0 0 0 1 1
5: 0 1 1 0 0 0 1
6: 0 1 0 1 1 1 1
7: 0 1 1 1 0 1 1
8: 0 1 1 0 1 1 1
9: 0 0 0 1 0 1 1
On the left hand side of the bar code a space represents a 0 and a # represents a 1.
On the right hand side of the bar code, a # represents a 0 and a space represents a 1
Alternatively (for the above): spaces always represent zeros and # characters always represent ones, but the representation is logically negated -- 1s and 0s are flipped -- on the right hand side of the bar code.
The UPC-A bar code structure
It begins with at least 9 spaces (which our imaginary bar code reader unfortunately doesn't always reproduce properly),
then has a # # sequence marking the start of the sequence,
then has the six "left hand" digits,
then has a # # sequence in the middle,
then has the six "right hand digits",
then has another # # (end sequence), and finally,
then ends with nine trailing spaces (which might be eaten by wiki edits, and in any event, were not quite captured correctly by our imaginary bar code reader).
Finally, the last digit is a checksum digit which may be used to help detect errors.
Verification
Multiply each digit in the represented 12 digit sequence by the corresponding number in (3,1,3,1,3,1,3,1,3,1,3,1) and add the products.
The sum (mod 10) must be 0 (must have a zero as its last digit) if the UPC number has been read correctly.
| #PicoLisp | PicoLisp | (de l2n (Lst)
(case Lst
((0 0 0 1 1 0 1) 0)
((0 0 1 1 0 0 1) 1)
((0 0 1 0 0 1 1) 2)
((0 1 1 1 1 0 1) 3)
((0 1 0 0 0 1 1) 4)
((0 1 1 0 0 0 1) 5)
((0 1 0 1 1 1 1) 6)
((0 1 1 1 0 1 1) 7)
((0 1 1 0 1 1 1) 8)
((0 0 0 1 0 1 1) 9) ) )
(de convs (Lst Flg)
(make
(for L Lst
(link
(if2 (= "#" L) Flg 0 1 1 0) ) ) ) )
(de getL (Lst)
(make
(cut 3 'Lst)
(do 6
(link (convs (cut 7 'Lst))) )
(cut 5 'Lst)
(do 6
(link (convs (cut 7 'Lst) T)) ) ) )
(de parse (Str)
(let Lst
(make
(link (clip (chop Str)))
(link (reverse (car (made)))) )
(find
'((N) (fully num? N))
(mapcar '((L) (mapcar l2n (getL L))) Lst) ) ) )
(de upc (Str)
(let Lst (parse Str)
(cons
Lst
(%
(apply + (mapcar * Lst (circ 3 1)))
10 ) ) ) )
(setq *U
(quote
" # # # ## # ## # ## ### ## ### ## #### # # # ## ## # # ## ## ### # ## ## ### # # # "
" # # # ## ## # #### # # ## # ## # ## # # # ### # ### ## ## ### # # ### ### # # # "
" # # # # # ### # # # # # # # # # # ## # ## # ## # ## # # #### ### ## # # "
" # # ## ## ## ## # # # # ### # ## ## # # # ## ## # ### ## ## # # #### ## # # # "
" # # ### ## # ## ## ### ## # ## # # ## # # ### # ## ## # # ### # ## ## # # # "
" # # # # ## ## # # # # ## ## # # # # # #### # ## # #### #### # # ## # #### # # "
" # # # ## ## # # ## ## # ### ## ## # # # # # # # # ### # # ### # # # # # "
" # # # # ## ## # # ## ## ### # # # # # ### ## ## ### ## ### ### ## # ## ### ## # # "
" # # ### ## ## # # #### # ## # #### # #### # # # # # ### # # ### # # # ### # # # "
" # # # #### ## # #### # # ## ## ### #### # # # # ### # ### ### # # ### # # # ### # # " ) )
(for L (mapcar upc *U)
(println (if (car L) @ 'invalid)) ) |
http://rosettacode.org/wiki/Update_a_configuration_file | Update a configuration file | We have a configuration file as follows:
# This is a configuration file in standard configuration file format
#
# Lines begininning with a hash or a semicolon are ignored by the application
# program. Blank lines are also ignored by the application program.
# The first word on each non comment line is the configuration option.
# Remaining words or numbers on the line are configuration parameter
# data fields.
# Note that configuration option names are not case sensitive. However,
# configuration parameter data is case sensitive and the lettercase must
# be preserved.
# This is a favourite fruit
FAVOURITEFRUIT banana
# This is a boolean that should be set
NEEDSPEELING
# This boolean is commented out
; SEEDSREMOVED
# How many bananas we have
NUMBEROFBANANAS 48
The task is to manipulate the configuration file as follows:
Disable the needspeeling option (using a semicolon prefix)
Enable the seedsremoved option by removing the semicolon and any leading whitespace
Change the numberofbananas parameter to 1024
Enable (or create if it does not exist in the file) a parameter for numberofstrawberries with a value of 62000
Note that configuration option names are not case sensitive. This means that changes should be effected, regardless of the case.
Options should always be disabled by prefixing them with a semicolon.
Lines beginning with hash symbols should not be manipulated and left unchanged in the revised file.
If a configuration option does not exist within the file (in either enabled or disabled form), it should be added during this update. Duplicate configuration option names in the file should be removed, leaving just the first entry.
For the purpose of this task, the revised file should contain appropriate entries, whether enabled or not for needspeeling,seedsremoved,numberofbananas and numberofstrawberries.)
The update should rewrite configuration option names in capital letters. However lines beginning with hashes and any parameter data must not be altered (eg the banana for favourite fruit must not become capitalized). The update process should also replace double semicolon prefixes with just a single semicolon (unless it is uncommenting the option, in which case it should remove all leading semicolons).
Any lines beginning with a semicolon or groups of semicolons, but no following option should be removed, as should any leading or trailing whitespace on the lines. Whitespace between the option and parameters should consist only of a single
space, and any non-ASCII extended characters, tabs characters, or control codes
(other than end of line markers), should also be removed.
Related tasks
Read a configuration file
| #Tcl | Tcl | package require Tcl 8.6
oo::class create Config {
variable filename contents
constructor fileName {
set filename $fileName
set contents {}
try {
set f [open $filename]
### Sanitize during input
foreach line [split [read $f] \n] {
if {[string match "#*" $line]} {
lappend contents $line
continue
}
if {[regexp {^;\W*$} $line]} continue
set line [string trim [regsub -all {[^\u0020-\u007e]} $line {}]]
if {[regexp {^(\W*)(\w+)(.*)$} $line -> a b c]} {
set line "[regsub -all {^;+} $a {;}][string toupper $b]$c"
}
lappend contents $line
}
} finally {
if {[info exists f]} {
close $f
}
}
}
method save {} {
set f [open $filename w]
puts $f [join $contents \n]
close $f
}
# Utility methods (not exposed API)
method Transform {pattern vars replacement} {
set matched 0
set line -1
set RE "(?i)^$pattern$"
foreach l $contents {
incr line
if {[uplevel 1 [list regexp $RE $l -> {*}$vars]]} {
if {$matched} {
set contents [lreplace $contents $line $line]
incr line -1
} else {
lset contents $line [uplevel 1 [list subst $replacement]]
}
set matched 1
}
}
return $matched
}
method Format {k v} {
set v " [string trimleft $v]"
return "[string toupper $k][string trimright $v]"
}
# Public API for modifying options
method enable {option} {
if {![my Transform ";?\\s*($option)\\M\s*(.*)" {k v} \
{[my Format $k $v]}]} {
lappend contents [my Format $option ""]
}
}
method disable {option} {
if {![my Transform ";?\\s*($option)\\M\s*(.*)" {k v} \
{; [my Format $k $v]}]} {
lappend contents "; [my Format $option ""]"
}
}
method set {option {value ""}} {
if {![my Transform ";?\\s*($option)\\M.*" k {[my Format $k $value]}]} {
lappend contents [my Format $option $value]
}
}
} |
http://rosettacode.org/wiki/User_input/Text | User input/Text | User input/Text is part of Short Circuit's Console Program Basics selection.
Task
Input a string and the integer 75000 from the text console.
See also: User input/Graphical
| #jq | jq | def read(int):
null | until( . == int; "Expecting \(int)" | stderr | input);
def read_string:
null | until( type == "string"; "Please enter a string" | stderr | input);
(read_string | "I see the string: \(.)"),
(read(75000) | "I see the expected integer: \(.)") |
http://rosettacode.org/wiki/User_input/Text | User input/Text | User input/Text is part of Short Circuit's Console Program Basics selection.
Task
Input a string and the integer 75000 from the text console.
See also: User input/Graphical
| #Julia | Julia |
print("String? ")
y = readline()
println("Your input was \"", y, "\".\n")
print("Integer? ")
y = readline()
try
y = parse(Int, y)
println("Your input was \"", y, "\".\n")
catch
println("Sorry, but \"", y, "\" does not compute as an integer.")
end
|
http://rosettacode.org/wiki/User_input/Graphical | User input/Graphical |
In this task, the goal is to input a string and the integer 75000, from graphical user interface.
See also: User input/Text
| #PowerShell | PowerShell | #region Define the Windows Form
[Void][Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms")
$Form1 = New-Object System.Windows.Forms.Form
$label1 = New-Object System.Windows.Forms.Label
$label2 = New-Object System.Windows.Forms.Label
$txtInputText = New-Object System.Windows.Forms.TextBox
$txtInputNumber = New-Object System.Windows.Forms.TextBox
$btnAccept = New-Object System.Windows.Forms.Button
$label3 = New-Object System.Windows.Forms.Label
$btnCancel = New-Object System.Windows.Forms.Button
$SuspendLayout
#
# label1
#
$label1.AutoSize = $true
$label1.Location = New-Object System.Drawing.Point(23, 36)
$label1.Name = "label1"
$label1.Size = New-Object System.Drawing.Size(34, 13)
$label1.TabIndex = 0
$label1.Text = "String"
#
# label2
#
$label2.AutoSize = $true
$label2.Location = New-Object System.Drawing.Point(13, 62)
$label2.Name = "label2"
$label2.Size = New-Object System.Drawing.Size(44, 13)
$label2.TabIndex = 1
$label2.Text = "Number"
#
# txtInputText
#
$txtInputText.Location = New-Object System.Drawing.Point(63, 33)
$txtInputText.Name = "txtInputText"
$txtInputText.Size = New-Object System.Drawing.Size(100, 20)
$txtInputText.TabIndex = 0
#
# txtInputNumber
#
$txtInputNumber.Location = New-Object System.Drawing.Point(63, 59)
$txtInputNumber.Name = "txtInputNumber"
$txtInputNumber.Size = New-Object System.Drawing.Size(100, 20)
$txtInputNumber.TabIndex = 1
$txtInputNumber.Text = "75000"
#
# btnAccept
#
$btnAccept.DialogResult = [System.Windows.Forms.DialogResult]::OK
$btnAccept.Location = New-Object System.Drawing.Point(16, 94)
$btnAccept.Name = "btnAccept"
$btnAccept.Size = New-Object System.Drawing.Size(75, 23)
$btnAccept.TabIndex = 2
$btnAccept.Text = "Accept"
$btnAccept.UseVisualStyleBackColor = $true
$btnAccept.add_Click({$rc="Accept"; $Form1.Close()})
#
# label3
#
$label3.AutoSize = $true
$label3.Location = New-Object System.Drawing.Point(13, 9)
$label3.Name = "label3"
$label3.Size = New-Object System.Drawing.Size(173, 13)
$label3.TabIndex = 5
$label3.Text = "Please input a string and a number:"
#
# btnCancel
#
$btnCancel.DialogResult = [System.Windows.Forms.DialogResult]::Cancel
$btnCancel.Location = New-Object System.Drawing.Point(97, 94)
$btnCancel.Name = "btnCancel"
$btnCancel.Size = New-Object System.Drawing.Size(75, 23)
$btnCancel.TabIndex = 3
$btnCancel.Text = "Cancel"
$btnCancel.UseVisualStyleBackColor = $true
#
# Form1
#
$Form1.AcceptButton = $btnAccept
$Form1.CancelButton = $btnCancel
$Form1.ClientSize = New-Object System.Drawing.Size(196, 129)
$Form1.ControlBox = $false
$Form1.Controls.Add($btnCancel)
$Form1.Controls.Add($label3)
$Form1.Controls.Add($btnAccept)
$Form1.Controls.Add($txtInputNumber)
$Form1.Controls.Add($txtInputText)
$Form1.Controls.Add($label2)
$Form1.Controls.Add($label1)
$Form1.Name = "Form1"
$Form1.Text = "RosettaCode"
#endregion Define the Windows Form
### Show the input form
$f = $Form1.ShowDialog()
if ( $f -eq [System.Windows.Forms.DialogResult]::Cancel ) { "User selected Cancel" }
else { "User entered `"{0}`" for the text and {1} for the number" -f $txtInputText.Text, $txtInputNumber.Text } |
http://rosettacode.org/wiki/UTF-8_encode_and_decode | UTF-8 encode and decode | As described in UTF-8 and in Wikipedia, UTF-8 is a popular encoding of (multi-byte) Unicode code-points into eight-bit octets.
The goal of this task is to write a encoder that takes a unicode code-point (an integer representing a unicode character) and returns a sequence of 1-4 bytes representing that character in the UTF-8 encoding.
Then you have to write the corresponding decoder that takes a sequence of 1-4 UTF-8 encoded bytes and return the corresponding unicode character.
Demonstrate the functionality of your encoder and decoder on the following five characters:
Character Name Unicode UTF-8 encoding (hex)
---------------------------------------------------------------------------------
A LATIN CAPITAL LETTER A U+0041 41
ö LATIN SMALL LETTER O WITH DIAERESIS U+00F6 C3 B6
Ж CYRILLIC CAPITAL LETTER ZHE U+0416 D0 96
€ EURO SIGN U+20AC E2 82 AC
𝄞 MUSICAL SYMBOL G CLEF U+1D11E F0 9D 84 9E
Provided below is a reference implementation in Common Lisp.
| #Scala | Scala | object UTF8EncodeAndDecode extends App {
val codePoints = Seq(0x0041, 0x00F6, 0x0416, 0x20AC, 0x1D11E)
def utf8Encode(codepoint: Int): Array[Byte] =
new String(Array[Int](codepoint), 0, 1).getBytes(StandardCharsets.UTF_8)
def utf8Decode(bytes: Array[Byte]): Int =
new String(bytes, StandardCharsets.UTF_8).codePointAt(0)
println("Char Name Unicode UTF-8 Decoded")
for (codePoint <- codePoints) {
val w = if (Character.isBmpCodePoint(codePoint)) 4 else 5 // Compute spacing
val bytes = utf8Encode(codePoint)
def leftAlignedHex = f"U+${codePoint}%04X"
val s = new StringBuilder()
bytes.foreach(byte => s ++= "%02X ".format(byte))
printf(s"%-${w}c %-36s %-7s %-${16 - w}s%c%n",
codePoint, Character.getName(codePoint), leftAlignedHex, s, utf8Decode(bytes))
} |
http://rosettacode.org/wiki/URL_encoding | URL encoding | Task
Provide a function or mechanism to convert a provided string into URL encoding representation.
In URL encoding, special characters, control characters and extended characters
are converted into a percent symbol followed by a two digit hexadecimal code,
So a space character encodes into %20 within the string.
For the purposes of this task, every character except 0-9, A-Z and a-z requires conversion, so the following characters all require conversion by default:
ASCII control codes (Character ranges 00-1F hex (0-31 decimal) and 7F (127 decimal).
ASCII symbols (Character ranges 32-47 decimal (20-2F hex))
ASCII symbols (Character ranges 58-64 decimal (3A-40 hex))
ASCII symbols (Character ranges 91-96 decimal (5B-60 hex))
ASCII symbols (Character ranges 123-126 decimal (7B-7E hex))
Extended characters with character codes of 128 decimal (80 hex) and above.
Example
The string "http://foo bar/" would be encoded as "http%3A%2F%2Ffoo%20bar%2F".
Variations
Lowercase escapes are legal, as in "http%3a%2f%2ffoo%20bar%2f".
Some standards give different rules: RFC 3986, Uniform Resource Identifier (URI): Generic Syntax, section 2.3, says that "-._~" should not be encoded. HTML 5, section 4.10.22.5 URL-encoded form data, says to preserve "-._*", and to encode space " " to "+". The options below provide for utilization of an exception string, enabling preservation (non encoding) of particular characters to meet specific standards.
Options
It is permissible to use an exception string (containing a set of symbols
that do not need to be converted).
However, this is an optional feature and is not a requirement of this task.
Related tasks
URL decoding
URL parser
| #Phix | Phix | --
-- demo\rosetta\encode_url.exw
-- ===========================
--
with javascript_semantics
function nib(integer b)
return b+iff(b<=9?'0':'A'-10)
end function
function encode_url(string s, string exclusions="", integer spaceplus=0)
string res = ""
for i=1 to length(s) do
integer ch = s[i]
if ch=' ' and spaceplus then
ch = '+'
elsif not find(ch,exclusions)
and (ch<'0'
or (ch>'9' and ch<'A')
or (ch>'Z' and ch<'a')
or ch>'z') then
res &= '%'
res &= nib(floor(ch/#10))
ch = nib(and_bits(ch,#0F))
end if
res &= ch
end for
return res
end function
printf(1,"%s\n",{encode_url("http://foo bar/")})
{} = wait_key()
|
http://rosettacode.org/wiki/Variables | Variables | Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| #LotusScript | LotusScript | Sub Click()
'a few declarations as example
Dim s as New NotesSession ' declaring a New NotesSession actually returns the current, active NotesSession
Dim i as Integer ' i = 0
Dim s as String ' s= ""
Dim v as Variant ' v is nothing
Dim l as Long ' l = 0
Dim doc as NotesDocument 'doc is EMTPY
'...
End Sub
|
http://rosettacode.org/wiki/Variables | Variables | Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| #Lua | Lua | a = 1 -- Here we declare a numeric variable
fruit = "banana" -- Here we declare a string datatype
needspeeling = True -- This is a boolean
local b = 2 -- This variable declaration is prefixed with a scope modifier |
http://rosettacode.org/wiki/Van_Eck_sequence | Van Eck sequence | The sequence is generated by following this pseudo-code:
A: The first term is zero.
Repeatedly apply:
If the last term is *new* to the sequence so far then:
B: The next term is zero.
Otherwise:
C: The next term is how far back this last term occured previously.
Example
Using A:
0
Using B:
0 0
Using C:
0 0 1
Using B:
0 0 1 0
Using C: (zero last occurred two steps back - before the one)
0 0 1 0 2
Using B:
0 0 1 0 2 0
Using C: (two last occurred two steps back - before the zero)
0 0 1 0 2 0 2 2
Using C: (two last occurred one step back)
0 0 1 0 2 0 2 2 1
Using C: (one last appeared six steps back)
0 0 1 0 2 0 2 2 1 6
...
Task
Create a function/procedure/method/subroutine/... to generate the Van Eck sequence of numbers.
Use it to display here, on this page:
The first ten terms of the sequence.
Terms 991 - to - 1000 of the sequence.
References
Don't Know (the Van Eck Sequence) - Numberphile video.
Wikipedia Article: Van Eck's Sequence.
OEIS sequence: A181391.
| #Wren | Wren | var max = 1000
var a = List.filled(max, 0)
var seen = {}
for (n in 0...max-1) {
var m = seen[a[n]]
if (m != null) a[n+1] = n - m
seen[a[n]] = n
}
System.print("The first ten terms of the Van Eck sequence are:")
System.print(a[0...10])
System.print("\nTerms 991 to 1000 of the sequence are:")
System.print(a[990..-1]) |
http://rosettacode.org/wiki/Van_Eck_sequence | Van Eck sequence | The sequence is generated by following this pseudo-code:
A: The first term is zero.
Repeatedly apply:
If the last term is *new* to the sequence so far then:
B: The next term is zero.
Otherwise:
C: The next term is how far back this last term occured previously.
Example
Using A:
0
Using B:
0 0
Using C:
0 0 1
Using B:
0 0 1 0
Using C: (zero last occurred two steps back - before the one)
0 0 1 0 2
Using B:
0 0 1 0 2 0
Using C: (two last occurred two steps back - before the zero)
0 0 1 0 2 0 2 2
Using C: (two last occurred one step back)
0 0 1 0 2 0 2 2 1
Using C: (one last appeared six steps back)
0 0 1 0 2 0 2 2 1 6
...
Task
Create a function/procedure/method/subroutine/... to generate the Van Eck sequence of numbers.
Use it to display here, on this page:
The first ten terms of the sequence.
Terms 991 - to - 1000 of the sequence.
References
Don't Know (the Van Eck Sequence) - Numberphile video.
Wikipedia Article: Van Eck's Sequence.
OEIS sequence: A181391.
| #XPL0 | XPL0 | int Seq(1001), Back, N, M, Term;
func New; \Return 'true' if last term is new to sequence
[for Back:= N-2 downto 1 do
if Seq(Back) = Seq(N-1) then return false;
return true;
];
func VanEck; \Return term of Van Eck sequence
[Seq(N):= if New then 0 else N-Back-1;
N:= N+1;
return Seq(N-1);
];
[N:= 1;
for M:= 1 to 1000 do
[Term:= VanEck;
if M<=10 or M>=991 then
[IntOut(0, Term);
if M=10 or M=1000 then Crlf(0) else Text(0, ", ");
];
];
] |
http://rosettacode.org/wiki/Variadic_function | Variadic function | Task
Create a function which takes in a variable number of arguments and prints each one on its own line.
Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime.
Functions of this type are also known as Variadic Functions.
Related task
Call a function
| #TIScript | TIScript |
function printAll(separator,argv..) {
if(argv.length)
stdout.print(argv[0]);
for (var i=1; i < argv.length; i++)
stdout.print(separator, argv[i]);
}
printAll(" ", 4, 3, 5, 6, 4, 3);
printAll(",", 4, 3, 5);
printAll("! ","Rosetta", "Code", "Is", "Awesome"); |
http://rosettacode.org/wiki/Variadic_function | Variadic function | Task
Create a function which takes in a variable number of arguments and prints each one on its own line.
Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime.
Functions of this type are also known as Variadic Functions.
Related task
Call a function
| #uBasic.2F4tH | uBasic/4tH | Push _Mary, _had, _a, _little, _lamb ' Push the hashes
Proc _PrintStrings (5) ' Print the string
Push 1, 4, 5, 19, 12, 3 ' Push the numbers
Print "Maximum is: ";FUNC(_Max(6)) ' Call the function
End
_PrintStrings Param(1) ' Print a variadic number of strings
Local(1)
For b@ = a@-1 To 0 Step -1 ' Reverse the hashes, load in array
@(b@) = Pop()
Next
For b@ = 0 To a@-1 ' Now call the appropriate subroutines
Proc @(b@)
Until b@ = a@-1
Print " "; ' Print a space
Next ' unless it is the last word
Print ' Terminate the string
Return
_Max Param(1) ' Calculate the maximum value
Local(3)
d@ = -(2^31) ' Set maximum to a tiny value
For b@ = 1 To a@ ' Get all values from the stack
c@ = Pop()
If c@ > d@ THEN d@ = c@ ' Change maximum if required
Next
Return (d@) ' Return the maximum
' Hashed labels
_Mary Print "Mary"; : Return
_had Print "had"; : Return
_a Print "a"; : Return
_little Print "little"; : Return
_lamb Print "lamb"; : Return |
http://rosettacode.org/wiki/Vector_products | Vector products | A vector is defined as having three dimensions as being represented by an ordered collection of three numbers: (X, Y, Z).
If you imagine a graph with the x and y axis being at right angles to each other and having a third, z axis coming out of the page, then a triplet of numbers, (X, Y, Z) would represent a point in the region, and a vector from the origin to the point.
Given the vectors:
A = (a1, a2, a3)
B = (b1, b2, b3)
C = (c1, c2, c3)
then the following common vector products are defined:
The dot product (a scalar quantity)
A • B = a1b1 + a2b2 + a3b3
The cross product (a vector quantity)
A x B = (a2b3 - a3b2, a3b1 - a1b3, a1b2 - a2b1)
The scalar triple product (a scalar quantity)
A • (B x C)
The vector triple product (a vector quantity)
A x (B x C)
Task
Given the three vectors:
a = ( 3, 4, 5)
b = ( 4, 3, 5)
c = (-5, -12, -13)
Create a named function/subroutine/method to compute the dot product of two vectors.
Create a function to compute the cross product of two vectors.
Optionally create a function to compute the scalar triple product of three vectors.
Optionally create a function to compute the vector triple product of three vectors.
Compute and display: a • b
Compute and display: a x b
Compute and display: a • (b x c), the scalar triple product.
Compute and display: a x (b x c), the vector triple product.
References
A starting page on Wolfram MathWorld is Vector Multiplication .
Wikipedia dot product.
Wikipedia cross product.
Wikipedia triple product.
Related tasks
Dot product
Quaternion type
| #Julia | Julia | using LinearAlgebra
const a = [3, 4, 5]
const b = [4, 3, 5]
const c = [-5, -12, -13]
println("Test Vectors:")
@show a b c
println("\nVector Products:")
@show a ⋅ b
@show a × b
@show a ⋅ (b × c)
@show a × (b × c) |
http://rosettacode.org/wiki/Validate_International_Securities_Identification_Number | Validate International Securities Identification Number | An International Securities Identification Number (ISIN) is a unique international identifier for a financial security such as a stock or bond.
Task
Write a function or program that takes a string as input, and checks whether it is a valid ISIN.
It is only valid if it has the correct format, and the embedded checksum is correct.
Demonstrate that your code passes the test-cases listed below.
Details
The format of an ISIN is as follows:
┌───────────── a 2-character ISO country code (A-Z)
│ ┌─────────── a 9-character security code (A-Z, 0-9)
│ │ ┌── a checksum digit (0-9)
AU0000XVGZA3
For this task, you may assume that any 2-character alphabetic sequence is a valid country code.
The checksum can be validated as follows:
Replace letters with digits, by converting each character from base 36 to base 10, e.g. AU0000XVGZA3 →1030000033311635103.
Perform the Luhn test on this base-10 number.
There is a separate task for this test: Luhn test of credit card numbers.
You don't have to replicate the implementation of this test here ─── you can just call the existing function from that task. (Add a comment stating if you did this.)
Test cases
ISIN
Validity
Comment
US0378331005
valid
US0373831005
not valid
The transposition typo is caught by the checksum constraint.
U50378331005
not valid
The substitution typo is caught by the format constraint.
US03378331005
not valid
The duplication typo is caught by the format constraint.
AU0000XVGZA3
valid
AU0000VXGZA3
valid
Unfortunately, not all transposition typos are caught by the checksum constraint.
FR0000988040
valid
(The comments are just informational. Your function should simply return a Boolean result. See #Raku for a reference solution.)
Related task:
Luhn test of credit card numbers
Also see
Interactive online ISIN validator
Wikipedia article: International Securities Identification Number
| #XPL0 | XPL0 | string 0; \use zero-terminated strings
func Luhn(Str); \Return 'true' if digits in Str pass Luhn test
char Str;
int Len, Sum, I, Dig;
[Len:= 0; \find length of Str
while Str(Len) do Len:= Len+1;
Sum:= 0; \sum even and odd digits
for I:= 0 to Len-1 do \(no need to reverse)
[if (I xor Len) & 1 then
Sum:= Sum + Str(I) - ^0
else [Dig:= Str(I) - ^0;
Dig:= Dig*2;
Sum:= Sum + Dig/10 + rem(0);
];
];
return rem(Sum/10) = 0;
]; \Luhn
func Valid(Str); \Return 'true' if valid ISIN code
char Str, Str2(100);
int Sum, I, J, C, V;
[J:= 0;
for I:= 0 to 12-1 do \convert letters in Str to digits in Str2
[C:= Str(I);
case of
C>=^0 & C<=^9: [Str2(J):= C; J:= J+1];
C>=^A & C<=^Z: [Str2(J):= (C-^A+10)/10 + ^0; J:= J+1;
Str2(J):= rem(0) + ^0; J:= J+1]
other return false;
if I=1 & J#4 then return false; \first two chars not letters
];
if Str(I) # 0 then return false; \too long
Str2(J):= 0; \terminate string
return Luhn(Str2);
]; \Valid
int ISIN, N;
[ISIN:= ["US0378331005",
"US0373831005",
"U50378331005",
"US03378331005",
"AU0000XVGZA3",
"AU0000VXGZA3",
"FR0000988040"];
for N:= 0 to 7-1 do
[Text(0, ISIN(N));
Text(0, if Valid(ISIN(N))
then " is valid"
else " is not valid");
CrLf(0);
];
] |
http://rosettacode.org/wiki/Validate_International_Securities_Identification_Number | Validate International Securities Identification Number | An International Securities Identification Number (ISIN) is a unique international identifier for a financial security such as a stock or bond.
Task
Write a function or program that takes a string as input, and checks whether it is a valid ISIN.
It is only valid if it has the correct format, and the embedded checksum is correct.
Demonstrate that your code passes the test-cases listed below.
Details
The format of an ISIN is as follows:
┌───────────── a 2-character ISO country code (A-Z)
│ ┌─────────── a 9-character security code (A-Z, 0-9)
│ │ ┌── a checksum digit (0-9)
AU0000XVGZA3
For this task, you may assume that any 2-character alphabetic sequence is a valid country code.
The checksum can be validated as follows:
Replace letters with digits, by converting each character from base 36 to base 10, e.g. AU0000XVGZA3 →1030000033311635103.
Perform the Luhn test on this base-10 number.
There is a separate task for this test: Luhn test of credit card numbers.
You don't have to replicate the implementation of this test here ─── you can just call the existing function from that task. (Add a comment stating if you did this.)
Test cases
ISIN
Validity
Comment
US0378331005
valid
US0373831005
not valid
The transposition typo is caught by the checksum constraint.
U50378331005
not valid
The substitution typo is caught by the format constraint.
US03378331005
not valid
The duplication typo is caught by the format constraint.
AU0000XVGZA3
valid
AU0000VXGZA3
valid
Unfortunately, not all transposition typos are caught by the checksum constraint.
FR0000988040
valid
(The comments are just informational. Your function should simply return a Boolean result. See #Raku for a reference solution.)
Related task:
Luhn test of credit card numbers
Also see
Interactive online ISIN validator
Wikipedia article: International Securities Identification Number
| #Yabasic | Yabasic | sub luhntest(cardnr$)
local i, j, s1, s2, l
cardnr$ = Trim$(cardnr$) // remove spaces
l = Len(cardnr$)
// sum odd numbers
For i = l To 1 Step -2
s1 = s1 + (asc(mid$(cardnr$, i, 1)) - Asc("0"))
Next
// sum even numbers
For i = l-1 To 1 Step -2
j = asc(mid$(cardnr$, i, 1)) - Asc("0")
j = j * 2
If j > 9 j = mod(j, 10) + 1
s2 = s2 + j
Next
return mod(s1 + s2, 10) = 0
End sub
// ------=< MAIN >=-----
data "US0378331005", "US0373831005", "U50378331005", "US03378331005", "AU0000XVGZA3", "AU0000VXGZA3", "FR0000988040", ""
do
read test_item$
if test_item$ = "" break
l = Len(test_item$)
If l <> 12 Then
Print test_item$, " Invalid, length <> 12 char."
Continue
End If
c1$ = mid$(test_item$, 1, 1) : c2$ = mid$(test_item$, 2, 1)
If c1$ < "A" Or c1$ > "Z" or c2$ < "A" or c2$ > "Z" Then
Print test_item$, " Invalid, number needs to start with 2 characters"
Continue
End If
test_str$ = ""
For n = 1 To l
x = asc(mid$(test_item$, n, 1)) - Asc("0")
// if is a letter we to correct for that
If x > 9 x = x - 7
If x < 10 Then
test_str$ = test_str$ + Str$(x)
Else // two digest number
test_str$ = test_str$ + Str$(int(x / 10)) + Str$(mod(x, 10))
End If
Next
Print test_item$;
if luhntest(test_str$) then print " Valid" else print " Invalid, checksum error" end if
loop
|
http://rosettacode.org/wiki/Van_der_Corput_sequence | Van der Corput sequence | When counting integers in binary, if you put a (binary) point to the righEasyLangt of the count then the column immediately to the left denotes a digit with a multiplier of
2
0
{\displaystyle 2^{0}}
; the digit in the next column to the left has a multiplier of
2
1
{\displaystyle 2^{1}}
; and so on.
So in the following table:
0.
1.
10.
11.
...
the binary number "10" is
1
×
2
1
+
0
×
2
0
{\displaystyle 1\times 2^{1}+0\times 2^{0}}
.
You can also have binary digits to the right of the “point”, just as in the decimal number system. In that case, the digit in the place immediately to the right of the point has a weight of
2
−
1
{\displaystyle 2^{-1}}
, or
1
/
2
{\displaystyle 1/2}
.
The weight for the second column to the right of the point is
2
−
2
{\displaystyle 2^{-2}}
or
1
/
4
{\displaystyle 1/4}
. And so on.
If you take the integer binary count of the first table, and reflect the digits about the binary point, you end up with the van der Corput sequence of numbers in base 2.
.0
.1
.01
.11
...
The third member of the sequence, binary 0.01, is therefore
0
×
2
−
1
+
1
×
2
−
2
{\displaystyle 0\times 2^{-1}+1\times 2^{-2}}
or
1
/
4
{\displaystyle 1/4}
.
Distribution of 2500 points each: Van der Corput (top) vs pseudorandom
0
≤
x
<
1
{\displaystyle 0\leq x<1}
Monte Carlo simulations
This sequence is also a superset of the numbers representable by the "fraction" field of an old IEEE floating point standard. In that standard, the "fraction" field represented the fractional part of a binary number beginning with "1." e.g. 1.101001101.
Hint
A hint at a way to generate members of the sequence is to modify a routine used to change the base of an integer:
>>> def base10change(n, base):
digits = []
while n:
n,remainder = divmod(n, base)
digits.insert(0, remainder)
return digits
>>> base10change(11, 2)
[1, 0, 1, 1]
the above showing that 11 in decimal is
1
×
2
3
+
0
×
2
2
+
1
×
2
1
+
1
×
2
0
{\displaystyle 1\times 2^{3}+0\times 2^{2}+1\times 2^{1}+1\times 2^{0}}
.
Reflected this would become .1101 or
1
×
2
−
1
+
1
×
2
−
2
+
0
×
2
−
3
+
1
×
2
−
4
{\displaystyle 1\times 2^{-1}+1\times 2^{-2}+0\times 2^{-3}+1\times 2^{-4}}
Task description
Create a function/method/routine that given n, generates the n'th term of the van der Corput sequence in base 2.
Use the function to compute and display the first ten members of the sequence. (The first member of the sequence is for n=0).
As a stretch goal/extra credit, compute and show members of the sequence for bases other than 2.
See also
The Basic Low Discrepancy Sequences
Non-decimal radices/Convert
Van der Corput sequence
| #Stata | Stata | mata
// 5th term of Van der Corput sequence
halton(1,1,5)
.625
// the first 10 terms of Van der Corput sequence
halton(10,1)
1
+---------+
1 | .5 |
2 | .25 |
3 | .75 |
4 | .125 |
5 | .625 |
6 | .375 |
7 | .875 |
8 | .0625 |
9 | .5625 |
10 | .3125 |
+---------+
// the first 10 terms of Van der Corput sequence in base 3
ghalton(10,3,0)
1
+---------------+
1 | .3333333333 |
2 | .6666666667 |
3 | .1111111111 |
4 | .4444444444 |
5 | .7777777778 |
6 | .2222222222 |
7 | .5555555556 |
8 | .8888888889 |
9 | .037037037 |
10 | .3703703704 |
+---------------+
end |
http://rosettacode.org/wiki/Van_der_Corput_sequence | Van der Corput sequence | When counting integers in binary, if you put a (binary) point to the righEasyLangt of the count then the column immediately to the left denotes a digit with a multiplier of
2
0
{\displaystyle 2^{0}}
; the digit in the next column to the left has a multiplier of
2
1
{\displaystyle 2^{1}}
; and so on.
So in the following table:
0.
1.
10.
11.
...
the binary number "10" is
1
×
2
1
+
0
×
2
0
{\displaystyle 1\times 2^{1}+0\times 2^{0}}
.
You can also have binary digits to the right of the “point”, just as in the decimal number system. In that case, the digit in the place immediately to the right of the point has a weight of
2
−
1
{\displaystyle 2^{-1}}
, or
1
/
2
{\displaystyle 1/2}
.
The weight for the second column to the right of the point is
2
−
2
{\displaystyle 2^{-2}}
or
1
/
4
{\displaystyle 1/4}
. And so on.
If you take the integer binary count of the first table, and reflect the digits about the binary point, you end up with the van der Corput sequence of numbers in base 2.
.0
.1
.01
.11
...
The third member of the sequence, binary 0.01, is therefore
0
×
2
−
1
+
1
×
2
−
2
{\displaystyle 0\times 2^{-1}+1\times 2^{-2}}
or
1
/
4
{\displaystyle 1/4}
.
Distribution of 2500 points each: Van der Corput (top) vs pseudorandom
0
≤
x
<
1
{\displaystyle 0\leq x<1}
Monte Carlo simulations
This sequence is also a superset of the numbers representable by the "fraction" field of an old IEEE floating point standard. In that standard, the "fraction" field represented the fractional part of a binary number beginning with "1." e.g. 1.101001101.
Hint
A hint at a way to generate members of the sequence is to modify a routine used to change the base of an integer:
>>> def base10change(n, base):
digits = []
while n:
n,remainder = divmod(n, base)
digits.insert(0, remainder)
return digits
>>> base10change(11, 2)
[1, 0, 1, 1]
the above showing that 11 in decimal is
1
×
2
3
+
0
×
2
2
+
1
×
2
1
+
1
×
2
0
{\displaystyle 1\times 2^{3}+0\times 2^{2}+1\times 2^{1}+1\times 2^{0}}
.
Reflected this would become .1101 or
1
×
2
−
1
+
1
×
2
−
2
+
0
×
2
−
3
+
1
×
2
−
4
{\displaystyle 1\times 2^{-1}+1\times 2^{-2}+0\times 2^{-3}+1\times 2^{-4}}
Task description
Create a function/method/routine that given n, generates the n'th term of the van der Corput sequence in base 2.
Use the function to compute and display the first ten members of the sequence. (The first member of the sequence is for n=0).
As a stretch goal/extra credit, compute and show members of the sequence for bases other than 2.
See also
The Basic Low Discrepancy Sequences
Non-decimal radices/Convert
Van der Corput sequence
| #Swift | Swift | func vanDerCorput(n: Int, base: Int, num: inout Int, denom: inout Int) {
var n = n, p = 0, q = 1
while n != 0 {
p = p * base + (n % base)
q *= base
n /= base
}
num = p
denom = q
while p != 0 {
n = p
p = q % p
q = n
}
num /= q
denom /= q
}
var num = 0
var denom = 0
for base in 2...5 {
print("base \(base): 0 ", terminator: "")
for n in 1..<10 {
vanDerCorput(n: n, base: base, num: &num, denom: &denom)
print("\(num)/\(denom) ", terminator: "")
}
print()
} |
http://rosettacode.org/wiki/URL_decoding | URL decoding | This task (the reverse of URL encoding and distinct from URL parser) is to provide a function
or mechanism to convert an URL-encoded string into its original unencoded form.
Test cases
The encoded string "http%3A%2F%2Ffoo%20bar%2F" should be reverted to the unencoded form "http://foo bar/".
The encoded string "google.com/search?q=%60Abdu%27l-Bah%C3%A1" should revert to the unencoded form "google.com/search?q=`Abdu'l-Bahá".
| #Oberon-2 | Oberon-2 |
MODULE URLDecoding;
IMPORT
URI := URI:String,
Out := NPCT:Console;
BEGIN
Out.String(URI.Unescape("http%3A%2F%2Ffoo%20bar%2F"));Out.Ln;
Out.String(URI.Unescape("google.com/search?q=%60Abdu%27l-Bah%C3%A1"));Out.Ln;
END URLDecoding.
|
http://rosettacode.org/wiki/URL_decoding | URL decoding | This task (the reverse of URL encoding and distinct from URL parser) is to provide a function
or mechanism to convert an URL-encoded string into its original unencoded form.
Test cases
The encoded string "http%3A%2F%2Ffoo%20bar%2F" should be reverted to the unencoded form "http://foo bar/".
The encoded string "google.com/search?q=%60Abdu%27l-Bah%C3%A1" should revert to the unencoded form "google.com/search?q=`Abdu'l-Bahá".
| #Objeck | Objeck |
class UrlDecode {
function : Main(args : String[]) ~ Nil {
Net.UrlUtility->Decode("http%3A%2F%2Ffoo%20bar%2F")->PrintLine();
}
}
|
http://rosettacode.org/wiki/UPC | UPC | Goal
Convert UPC bar codes to decimal.
Specifically:
The UPC standard is actually a collection of standards -- physical standards, data format standards, product reference standards...
Here, in this task, we will focus on some of the data format standards, with an imaginary physical+electrical implementation which converts physical UPC bar codes to ASCII (with spaces and # characters representing the presence or absence of ink).
Sample input
Below, we have a representation of ten different UPC-A bar codes read by our imaginary bar code reader:
# # # ## # ## # ## ### ## ### ## #### # # # ## ## # # ## ## ### # ## ## ### # # #
# # # ## ## # #### # # ## # ## # ## # # # ### # ### ## ## ### # # ### ### # # #
# # # # # ### # # # # # # # # # # ## # ## # ## # ## # # #### ### ## # #
# # ## ## ## ## # # # # ### # ## ## # # # ## ## # ### ## ## # # #### ## # # #
# # ### ## # ## ## ### ## # ## # # ## # # ### # ## ## # # ### # ## ## # # #
# # # # ## ## # # # # ## ## # # # # # #### # ## # #### #### # # ## # #### # #
# # # ## ## # # ## ## # ### ## ## # # # # # # # # ### # # ### # # # # #
# # # # ## ## # # ## ## ### # # # # # ### ## ## ### ## ### ### ## # ## ### ## # #
# # ### ## ## # # #### # ## # #### # #### # # # # # ### # # ### # # # ### # # #
# # # #### ## # #### # # ## ## ### #### # # # # ### # ### ### # # ### # # # ### # #
Some of these were entered upside down, and one entry has a timing error.
Task
Implement code to find the corresponding decimal representation of each, rejecting the error.
Extra credit for handling the rows entered upside down (the other option is to reject them).
Notes
Each digit is represented by 7 bits:
0: 0 0 0 1 1 0 1
1: 0 0 1 1 0 0 1
2: 0 0 1 0 0 1 1
3: 0 1 1 1 1 0 1
4: 0 1 0 0 0 1 1
5: 0 1 1 0 0 0 1
6: 0 1 0 1 1 1 1
7: 0 1 1 1 0 1 1
8: 0 1 1 0 1 1 1
9: 0 0 0 1 0 1 1
On the left hand side of the bar code a space represents a 0 and a # represents a 1.
On the right hand side of the bar code, a # represents a 0 and a space represents a 1
Alternatively (for the above): spaces always represent zeros and # characters always represent ones, but the representation is logically negated -- 1s and 0s are flipped -- on the right hand side of the bar code.
The UPC-A bar code structure
It begins with at least 9 spaces (which our imaginary bar code reader unfortunately doesn't always reproduce properly),
then has a # # sequence marking the start of the sequence,
then has the six "left hand" digits,
then has a # # sequence in the middle,
then has the six "right hand digits",
then has another # # (end sequence), and finally,
then ends with nine trailing spaces (which might be eaten by wiki edits, and in any event, were not quite captured correctly by our imaginary bar code reader).
Finally, the last digit is a checksum digit which may be used to help detect errors.
Verification
Multiply each digit in the represented 12 digit sequence by the corresponding number in (3,1,3,1,3,1,3,1,3,1,3,1) and add the products.
The sum (mod 10) must be 0 (must have a zero as its last digit) if the UPC number has been read correctly.
| #Python | Python | """UPC-A barcode reader. Requires Python =>3.6"""
import itertools
import re
RE_BARCODE = re.compile(
r"^(?P<s_quiet> +)" # quiet zone
r"(?P<s_guard># #)" # start guard
r"(?P<left>[ #]{42})" # left digits
r"(?P<m_guard> # # )" # middle guard
r"(?P<right>[ #]{42})" # right digits
r"(?P<e_guard># #)" # end guard
r"(?P<e_quiet> +)$" # quiet zone
)
LEFT_DIGITS = {
(0, 0, 0, 1, 1, 0, 1): 0,
(0, 0, 1, 1, 0, 0, 1): 1,
(0, 0, 1, 0, 0, 1, 1): 2,
(0, 1, 1, 1, 1, 0, 1): 3,
(0, 1, 0, 0, 0, 1, 1): 4,
(0, 1, 1, 0, 0, 0, 1): 5,
(0, 1, 0, 1, 1, 1, 1): 6,
(0, 1, 1, 1, 0, 1, 1): 7,
(0, 1, 1, 0, 1, 1, 1): 8,
(0, 0, 0, 1, 0, 1, 1): 9,
}
RIGHT_DIGITS = {
(1, 1, 1, 0, 0, 1, 0): 0,
(1, 1, 0, 0, 1, 1, 0): 1,
(1, 1, 0, 1, 1, 0, 0): 2,
(1, 0, 0, 0, 0, 1, 0): 3,
(1, 0, 1, 1, 1, 0, 0): 4,
(1, 0, 0, 1, 1, 1, 0): 5,
(1, 0, 1, 0, 0, 0, 0): 6,
(1, 0, 0, 0, 1, 0, 0): 7,
(1, 0, 0, 1, 0, 0, 0): 8,
(1, 1, 1, 0, 1, 0, 0): 9,
}
MODULES = {
" ": 0,
"#": 1,
}
DIGITS_PER_SIDE = 6
MODULES_PER_DIGIT = 7
class ParityError(Exception):
"""Exception raised when a parity error is found."""
class ChecksumError(Exception):
"""Exception raised when check digit does not match."""
def group(iterable, n):
"""Chunk the iterable into groups of size ``n``."""
args = [iter(iterable)] * n
return tuple(itertools.zip_longest(*args))
def parse(barcode):
"""Return the 12 digits represented by the given barcode. Raises a
ParityError if any digit fails the parity check."""
match = RE_BARCODE.match(barcode)
# Translate bars and spaces to 1s and 0s so we can do arithmetic
# with them. Group "modules" into chunks of 7 as we go.
left = group((MODULES[c] for c in match.group("left")), MODULES_PER_DIGIT)
right = group((MODULES[c] for c in match.group("right")), MODULES_PER_DIGIT)
# Parity check
left, right = check_parity(left, right)
# Lookup digits
return tuple(
itertools.chain(
(LEFT_DIGITS[d] for d in left),
(RIGHT_DIGITS[d] for d in right),
)
)
def check_parity(left, right):
"""Check left and right parity. Flip left and right if the barcode
was scanned upside down."""
# When reading from left to right, each digit on the left should
# have odd parity, and each digit on the right should have even
# parity.
left_parity = sum(sum(d) % 2 for d in left)
right_parity = sum(sum(d) % 2 for d in right)
# Use left and right parity to check if the barcode was scanned
# upside down. Flip it if it was.
if left_parity == 0 and right_parity == DIGITS_PER_SIDE:
_left = tuple(tuple(reversed(d)) for d in reversed(right))
right = tuple(tuple(reversed(d)) for d in reversed(left))
left = _left
elif left_parity != DIGITS_PER_SIDE or right_parity != 0:
# Error condition. Mixed parity.
error = tuple(
itertools.chain(
(LEFT_DIGITS.get(d, "_") for d in left),
(RIGHT_DIGITS.get(d, "_") for d in right),
)
)
raise ParityError(" ".join(str(d) for d in error))
return left, right
def checksum(digits):
"""Return the check digit for the given digits. Raises a
ChecksumError if the check digit does not match."""
odds = (digits[i] for i in range(0, 11, 2))
evens = (digits[i] for i in range(1, 10, 2))
check_digit = (sum(odds) * 3 + sum(evens)) % 10
if check_digit != 0:
check_digit = 10 - check_digit
if digits[-1] != check_digit:
raise ChecksumError(str(check_digit))
return check_digit
def main():
barcodes = [
" # # # ## # ## # ## ### ## ### ## #### # # # ## ## # # ## ## ### # ## ## ### # # # ",
" # # # ## ## # #### # # ## # ## # ## # # # ### # ### ## ## ### # # ### ### # # # ",
" # # # # # ### # # # # # # # # # # ## # ## # ## # ## # # #### ### ## # # ",
" # # ## ## ## ## # # # # ### # ## ## # # # ## ## # ### ## ## # # #### ## # # # ",
" # # ### ## # ## ## ### ## # ## # # ## # # ### # ## ## # # ### # ## ## # # # ",
" # # # # ## ## # # # # ## ## # # # # # #### # ## # #### #### # # ## # #### # # ",
" # # # ## ## # # ## ## # ### ## ## # # # # # # # # ### # # ### # # # # # ",
" # # # # ## ## # # ## ## ### # # # # # ### ## ## ### ## ### ### ## # ## ### ## # # ",
" # # ### ## ## # # #### # ## # #### # #### # # # # # ### # # ### # # # ### # # # ",
" # # # #### ## # #### # # ## ## ### #### # # # # ### # ### ### # # ### # # # ### # # ",
" # # # #### ## # #### # # ## ## ### #### # # # # ### # ### ### # # ### ## ## # ### # # ",
]
for barcode in barcodes:
try:
digits = parse(barcode)
except ParityError as err:
print(f"{err} parity error!")
continue
try:
check_digit = checksum(digits)
except ChecksumError as err:
print(f"{' '.join(str(d) for d in digits)} checksum error! ({err})")
continue
print(f"{' '.join(str(d) for d in digits)}")
if __name__ == "__main__":
main()
|
http://rosettacode.org/wiki/Update_a_configuration_file | Update a configuration file | We have a configuration file as follows:
# This is a configuration file in standard configuration file format
#
# Lines begininning with a hash or a semicolon are ignored by the application
# program. Blank lines are also ignored by the application program.
# The first word on each non comment line is the configuration option.
# Remaining words or numbers on the line are configuration parameter
# data fields.
# Note that configuration option names are not case sensitive. However,
# configuration parameter data is case sensitive and the lettercase must
# be preserved.
# This is a favourite fruit
FAVOURITEFRUIT banana
# This is a boolean that should be set
NEEDSPEELING
# This boolean is commented out
; SEEDSREMOVED
# How many bananas we have
NUMBEROFBANANAS 48
The task is to manipulate the configuration file as follows:
Disable the needspeeling option (using a semicolon prefix)
Enable the seedsremoved option by removing the semicolon and any leading whitespace
Change the numberofbananas parameter to 1024
Enable (or create if it does not exist in the file) a parameter for numberofstrawberries with a value of 62000
Note that configuration option names are not case sensitive. This means that changes should be effected, regardless of the case.
Options should always be disabled by prefixing them with a semicolon.
Lines beginning with hash symbols should not be manipulated and left unchanged in the revised file.
If a configuration option does not exist within the file (in either enabled or disabled form), it should be added during this update. Duplicate configuration option names in the file should be removed, leaving just the first entry.
For the purpose of this task, the revised file should contain appropriate entries, whether enabled or not for needspeeling,seedsremoved,numberofbananas and numberofstrawberries.)
The update should rewrite configuration option names in capital letters. However lines beginning with hashes and any parameter data must not be altered (eg the banana for favourite fruit must not become capitalized). The update process should also replace double semicolon prefixes with just a single semicolon (unless it is uncommenting the option, in which case it should remove all leading semicolons).
Any lines beginning with a semicolon or groups of semicolons, but no following option should be removed, as should any leading or trailing whitespace on the lines. Whitespace between the option and parameters should consist only of a single
space, and any non-ASCII extended characters, tabs characters, or control codes
(other than end of line markers), should also be removed.
Related tasks
Read a configuration file
| #TXR | TXR | VAR # define or update VAR as a true-valued boolean
VAR= # ensure "; VAR" in the config file.
VAR=VAL # ensure "VAR VAL" in the config file |
http://rosettacode.org/wiki/Update_a_configuration_file | Update a configuration file | We have a configuration file as follows:
# This is a configuration file in standard configuration file format
#
# Lines begininning with a hash or a semicolon are ignored by the application
# program. Blank lines are also ignored by the application program.
# The first word on each non comment line is the configuration option.
# Remaining words or numbers on the line are configuration parameter
# data fields.
# Note that configuration option names are not case sensitive. However,
# configuration parameter data is case sensitive and the lettercase must
# be preserved.
# This is a favourite fruit
FAVOURITEFRUIT banana
# This is a boolean that should be set
NEEDSPEELING
# This boolean is commented out
; SEEDSREMOVED
# How many bananas we have
NUMBEROFBANANAS 48
The task is to manipulate the configuration file as follows:
Disable the needspeeling option (using a semicolon prefix)
Enable the seedsremoved option by removing the semicolon and any leading whitespace
Change the numberofbananas parameter to 1024
Enable (or create if it does not exist in the file) a parameter for numberofstrawberries with a value of 62000
Note that configuration option names are not case sensitive. This means that changes should be effected, regardless of the case.
Options should always be disabled by prefixing them with a semicolon.
Lines beginning with hash symbols should not be manipulated and left unchanged in the revised file.
If a configuration option does not exist within the file (in either enabled or disabled form), it should be added during this update. Duplicate configuration option names in the file should be removed, leaving just the first entry.
For the purpose of this task, the revised file should contain appropriate entries, whether enabled or not for needspeeling,seedsremoved,numberofbananas and numberofstrawberries.)
The update should rewrite configuration option names in capital letters. However lines beginning with hashes and any parameter data must not be altered (eg the banana for favourite fruit must not become capitalized). The update process should also replace double semicolon prefixes with just a single semicolon (unless it is uncommenting the option, in which case it should remove all leading semicolons).
Any lines beginning with a semicolon or groups of semicolons, but no following option should be removed, as should any leading or trailing whitespace on the lines. Whitespace between the option and parameters should consist only of a single
space, and any non-ASCII extended characters, tabs characters, or control codes
(other than end of line markers), should also be removed.
Related tasks
Read a configuration file
| #VBScript | VBScript |
Set objFSO = CreateObject("Scripting.FileSystemObject")
'Paramater lookups
Set objParamLookup = CreateObject("Scripting.Dictionary")
With objParamLookup
.Add "FAVOURITEFRUIT", "banana"
.Add "NEEDSPEELING", ""
.Add "SEEDSREMOVED", ""
.Add "NUMBEROFBANANAS", "1024"
.Add "NUMBEROFSTRAWBERRIES", "62000"
End With
'Open the config file for reading.
Set objInFile = objFSO.OpenTextFile(objFSO.GetParentFolderName(WScript.ScriptFullName) &_
"\IN_config.txt",1)
'Initialize output.
Output = ""
Isnumberofstrawberries = False
With objInFile
Do Until .AtEndOfStream
line = .ReadLine
If Left(line,1) = "#" Or line = "" Then
Output = Output & line & vbCrLf
ElseIf Left(line,1) = " " And InStr(line,"#") Then
Output = Output & Mid(line,InStr(1,line,"#"),1000) & vbCrLf
ElseIf Replace(Replace(line,";","")," ","") <> "" Then
If InStr(1,line,"FAVOURITEFRUIT",1) Then
Output = Output & "FAVOURITEFRUIT" & " " & objParamLookup.Item("FAVOURITEFRUIT") & vbCrLf
ElseIf InStr(1,line,"NEEDSPEELING",1) Then
Output = Output & "; " & "NEEDSPEELING" & vbCrLf
ElseIf InStr(1,line,"SEEDSREMOVED",1) Then
Output = Output & "SEEDSREMOVED" & vbCrLf
ElseIf InStr(1,line,"NUMBEROFBANANAS",1) Then
Output = Output & "NUMBEROFBANANAS" & " " & objParamLookup.Item("NUMBEROFBANANAS") & vbCrLf
ElseIf InStr(1,line,"NUMBEROFSTRAWBERRIES",1) Then
Output = Output & "NUMBEROFSTRAWBERRIES" & " " & objParamLookup.Item("NUMBEROFSTRAWBERRIES") & vbCrLf
Isnumberofstrawberries = True
End If
End If
Loop
If Isnumberofstrawberries = False Then
Output = Output & "NUMBEROFSTRAWBERRIES" & " " & objParamLookup.Item("NUMBEROFSTRAWBERRIES") & vbCrLf
Isnumberofstrawberries = True
End If
.Close
End With
'Create a new config file.
Set objOutFile = objFSO.OpenTextFile(objFSO.GetParentFolderName(WScript.ScriptFullName) &_
"\OUT_config.txt",2,True)
With objOutFile
.Write Output
.Close
End With
Set objFSO = Nothing
Set objParamLookup = Nothing
|
http://rosettacode.org/wiki/User_input/Text | User input/Text | User input/Text is part of Short Circuit's Console Program Basics selection.
Task
Input a string and the integer 75000 from the text console.
See also: User input/Graphical
| #Kite | Kite |
System.file.stdout|write("Enter a String ");
string = System.file.stdin|readline();
|
http://rosettacode.org/wiki/User_input/Text | User input/Text | User input/Text is part of Short Circuit's Console Program Basics selection.
Task
Input a string and the integer 75000 from the text console.
See also: User input/Graphical
| #Kotlin | Kotlin | // version 1.1
fun main(args: Array<String>) {
print("Enter a string : ")
val s = readLine()!!
println(s)
do {
print("Enter 75000 : ")
val number = readLine()!!.toInt()
} while (number != 75000)
} |
http://rosettacode.org/wiki/User_input/Graphical | User input/Graphical |
In this task, the goal is to input a string and the integer 75000, from graphical user interface.
See also: User input/Text
| #Processing | Processing | import javax.swing.JOptionPane;
int number = int(JOptionPane.showInputDialog ("Enter an Integer"));
println(number);
String string = JOptionPane.showInputDialog ("Enter a String");
println(string); |
http://rosettacode.org/wiki/User_input/Graphical | User input/Graphical |
In this task, the goal is to input a string and the integer 75000, from graphical user interface.
See also: User input/Text
| #PureBasic | PureBasic | string$=InputRequester("Some Title","Enter a string","")
variable=Val(InputRequester("Some other Title","Enter a Number","75000")) |
http://rosettacode.org/wiki/UTF-8_encode_and_decode | UTF-8 encode and decode | As described in UTF-8 and in Wikipedia, UTF-8 is a popular encoding of (multi-byte) Unicode code-points into eight-bit octets.
The goal of this task is to write a encoder that takes a unicode code-point (an integer representing a unicode character) and returns a sequence of 1-4 bytes representing that character in the UTF-8 encoding.
Then you have to write the corresponding decoder that takes a sequence of 1-4 UTF-8 encoded bytes and return the corresponding unicode character.
Demonstrate the functionality of your encoder and decoder on the following five characters:
Character Name Unicode UTF-8 encoding (hex)
---------------------------------------------------------------------------------
A LATIN CAPITAL LETTER A U+0041 41
ö LATIN SMALL LETTER O WITH DIAERESIS U+00F6 C3 B6
Ж CYRILLIC CAPITAL LETTER ZHE U+0416 D0 96
€ EURO SIGN U+20AC E2 82 AC
𝄞 MUSICAL SYMBOL G CLEF U+1D11E F0 9D 84 9E
Provided below is a reference implementation in Common Lisp.
| #Seed7 | Seed7 | $ include "seed7_05.s7i";
include "unicode.s7i";
include "console.s7i";
include "bytedata.s7i";
const proc: main is func
local
var char: ch is ' ';
var string: utf8 is "";
begin
OUT := STD_CONSOLE;
writeln("Character Unicode UTF-8 encoding (hex) Decoded");
writeln("-------------------------------------------------");
for ch range "AöЖ€𝄞" do
utf8 := striToUtf8(str(ch));
writeln(ch rpad 11 <& "U+" <& ord(ch) radix 16 lpad0 4 rpad 7 <&
hex(utf8) rpad 22 <& utf8ToStri(utf8));
end for;
end func; |
http://rosettacode.org/wiki/UTF-8_encode_and_decode | UTF-8 encode and decode | As described in UTF-8 and in Wikipedia, UTF-8 is a popular encoding of (multi-byte) Unicode code-points into eight-bit octets.
The goal of this task is to write a encoder that takes a unicode code-point (an integer representing a unicode character) and returns a sequence of 1-4 bytes representing that character in the UTF-8 encoding.
Then you have to write the corresponding decoder that takes a sequence of 1-4 UTF-8 encoded bytes and return the corresponding unicode character.
Demonstrate the functionality of your encoder and decoder on the following five characters:
Character Name Unicode UTF-8 encoding (hex)
---------------------------------------------------------------------------------
A LATIN CAPITAL LETTER A U+0041 41
ö LATIN SMALL LETTER O WITH DIAERESIS U+00F6 C3 B6
Ж CYRILLIC CAPITAL LETTER ZHE U+0416 D0 96
€ EURO SIGN U+20AC E2 82 AC
𝄞 MUSICAL SYMBOL G CLEF U+1D11E F0 9D 84 9E
Provided below is a reference implementation in Common Lisp.
| #Sidef | Sidef | func utf8_encoder(Number code) {
code.chr.encode('UTF-8').bytes.map{.chr}
}
func utf8_decoder(Array bytes) {
bytes.map{.ord}.decode('UTF-8')
}
for n in ([0x0041, 0x00F6, 0x0416, 0x20AC, 0x1D11E]) {
var encoded = utf8_encoder(n)
var decoded = utf8_decoder(encoded)
assert_eq(n, decoded.ord)
say "#{decoded} -> #{encoded}"
} |
http://rosettacode.org/wiki/URL_encoding | URL encoding | Task
Provide a function or mechanism to convert a provided string into URL encoding representation.
In URL encoding, special characters, control characters and extended characters
are converted into a percent symbol followed by a two digit hexadecimal code,
So a space character encodes into %20 within the string.
For the purposes of this task, every character except 0-9, A-Z and a-z requires conversion, so the following characters all require conversion by default:
ASCII control codes (Character ranges 00-1F hex (0-31 decimal) and 7F (127 decimal).
ASCII symbols (Character ranges 32-47 decimal (20-2F hex))
ASCII symbols (Character ranges 58-64 decimal (3A-40 hex))
ASCII symbols (Character ranges 91-96 decimal (5B-60 hex))
ASCII symbols (Character ranges 123-126 decimal (7B-7E hex))
Extended characters with character codes of 128 decimal (80 hex) and above.
Example
The string "http://foo bar/" would be encoded as "http%3A%2F%2Ffoo%20bar%2F".
Variations
Lowercase escapes are legal, as in "http%3a%2f%2ffoo%20bar%2f".
Some standards give different rules: RFC 3986, Uniform Resource Identifier (URI): Generic Syntax, section 2.3, says that "-._~" should not be encoded. HTML 5, section 4.10.22.5 URL-encoded form data, says to preserve "-._*", and to encode space " " to "+". The options below provide for utilization of an exception string, enabling preservation (non encoding) of particular characters to meet specific standards.
Options
It is permissible to use an exception string (containing a set of symbols
that do not need to be converted).
However, this is an optional feature and is not a requirement of this task.
Related tasks
URL decoding
URL parser
| #PHP | PHP | <?php
$s = 'http://foo/bar/';
$s = rawurlencode($s);
?> |
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