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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
#PicoLisp
PicoLisp
(de urlEncodeTooMuch (Str) (pack (mapcar '((C) (if (or (>= "9" C "0") (>= "Z" (uppc C) "A")) C (list '% (hex (char C))) ) ) (chop Str) ) ) )
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
#M2000_Interpreter
M2000 Interpreter
  \\ M2000 use inference to state the type of a new variable, at run time \\ We can use literals of a numeric type \\ @ for Decimal \\ # for Currency \\ ~ for Single \\ & for Long (32bit) \\ % for Integer (16bit) \\ Double and Boolean have no symboles Module TopA { Module Alfa { Print A=10000, Type$(A)="Double" \\ A is local, we use = A=10@ Print A=10, Type$(A) \\ Or we can state the type before Def Currency K, Z=500, M K=1000 \\ Currency Currency Currency Print Type$(K), Type$(Z), Type$(M) Def Double K1, K2 as Integer=10, K3=1 \\ double integer double Print Type$(K1), Type$(K2), Type$(K3) Mb=1=1 \\ We get a boolean Print Type$(Mb) Def boolean Mb1=True Print Type$(Mb1) \\ True and False are Double -1 and 0 not Boolean Mb3=True Print Type$(Mb3)="Double" \\ For strings we have to use $ (like in old Basic) A$="This is a String" Global G1 as boolean = True \\ To change a global variable we have to use <= G1<=1=0 \\ If we do this: G1=1=0 we make a local variable, and shadow global \\ In a For Object {} we can make temporary variables For This { Local G1=122.1212 Print G1, Type$(G1)="Double" } Print G1, Type$(G1)="Boolean" } \\ shadow A for this module only A=100 \\ Now we call Alfa Alfa Print (A=100)=True } Global A=10000 TopA Print A=10000 Module CheckStatic { \\ clear static variables and variables (for this module) Clear Module K { \\ if no A exist created with value 100@ \\ Static variables can't be referenced Static A=100@ Print A, Type$(A)="Decimal" A++ } For i=1 to 10 : K : Next i Print A=10000 } CheckStatic Print A=10000   \\ reference and use of stack of values C=100& Module ChangeC { \\ we leave arguments in stack of values Module HereChangeC (&f) { \\ interpreter execute a Read &f f++ } \\ now we call HereChangeC passing current stack of values HereChangeC } \\ Calling a module done without checking for what parameters a module take ChangeC &C Print C, Type$(C)="Long" K=10010001001@ ChangeC &K Print K, Type$(K)="Decimal" Module TypeRef (&x as Double) { Print x x++ } D=100 TypeRef &D Try ok { TypeRef &K } If Error or Not Ok then Print Error$ ' we get wrong data type  
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
#Maple
Maple
a := 1: print ("a is "||a); "a is 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.
#zkl
zkl
fcn vanEck(startAt=0){ // --> iterator (startAt).walker(*).tweak(fcn(n,seen,rprev){ prev,t := rprev.value, n - seen.find(prev,n); seen[prev] = n; rprev.set(t); t }.fp1(Dictionary(),Ref(startAt))).push(startAt) }
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
#Unicon
Unicon
f = %gP*=   #show+   main = f <'foo',12.5,('x','y'),100>
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
#Ursala
Ursala
f = %gP*=   #show+   main = f <'foo',12.5,('x','y'),100>
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
#V
V
[myfn [zero? not] [swap puts pred] while ].   100 200 300 400 500 3 myfn
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
#Kotlin
Kotlin
// version 1.1.2   class Vector3D(val x: Double, val y: Double, val z: Double) { infix fun dot(v: Vector3D) = x * v.x + y * v.y + z * v.z   infix fun cross(v: Vector3D) = Vector3D(y * v.z - z * v.y, z * v.x - x * v.z, x * v.y - y * v.x)   fun scalarTriple(v: Vector3D, w: Vector3D) = this dot (v cross w)   fun vectorTriple(v: Vector3D, w: Vector3D) = this cross (v cross w)   override fun toString() = "($x, $y, $z)" }   fun main(args: Array<String>) { val a = Vector3D(3.0, 4.0, 5.0) val b = Vector3D(4.0, 3.0, 5.0) val c = Vector3D(-5.0, -12.0, -13.0) println("a = $a") println("b = $b") println("c = $c") println() println("a . b = ${a dot b}") println("a x b = ${a cross b}") println("a . b x c = ${a.scalarTriple(b, c)}") println("a x b x c = ${a.vectorTriple(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
#zkl
zkl
fcn validateISIN(isin){ RegExp(String("^","[A-Z]"*2,"[A-Z0-9]"*9,"[0-9]$")).matches(isin) and luhnTest(isin.split("").apply("toInt",36).concat().toInt()) } fcn luhnTest(n){ 0 == (n.split().reverse().reduce(fcn(s,n,clk){ s + if(clk.inc()%2) n else 2*n%10 + n/5 },0,Ref(1)) %10) }
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
#Tcl
Tcl
proc digitReverse {n {base 2}} { set n [expr {[set neg [expr {$n < 0}]] ? -$n : $n}] set result 0.0 set bit [expr {1.0 / $base}] for {} {$n > 0} {set n [expr {$n / $base}]} { set result [expr {$result + $bit * ($n % $base)}] set bit [expr {$bit / $base}] } return [expr {$neg ? -$result : $result}] }
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
#VBA
VBA
Private Function vdc(ByVal n As Integer, BASE As Variant) As Variant Dim res As String Dim digit As Integer, g As Integer, denom As Integer denom = 1 Do While n denom = denom * BASE digit = n Mod BASE n = n \ BASE res = res & CStr(digit) '+ "0" Loop vdc = IIf(Len(res) = 0, "0", "0." & res) End Function   Public Sub show_vdc() Dim v As Variant, j As Integer For i = 2 To 5 Debug.Print "Base "; i; ": "; For j = 0 To 9 v = vdc(j, i) Debug.Print v; " "; Next j Debug.Print Next i End Sub
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".
#Objective-C
Objective-C
NSString *encoded = @"http%3A%2F%2Ffoo%20bar%2F"; NSString *normal = [encoded stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding]; NSLog(@"%@", normal);
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".
#OCaml
OCaml
$ ocaml # #use "topfind";; # #require "netstring";;   # Netencoding.Url.decode "http%3A%2F%2Ffoo%20bar%2F" ;; - : string = "http://foo bar/"
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.
#Racket
Racket
#lang racket   ;; inspired by Kotlin   (define (is-#? c) (char=? c #\#))   (define left-digits (for/hash ((i (in-naturals)) (c '((#f #f #t #t #f) (#f #t #t #f #f) (#f #t #f #f #t) (#t #t #t #t #f) (#t #f #f #f #t) (#t #t #f #f #f) (#t #f #t #t #t) (#t #t #t #f #t) (#t #t #f #t #t) (#f #f #t #f #t)))) (values `(#f ,@c #t) i)))   (define right-digits (for/hash (([k v] left-digits)) (values (map not k) v)))   (define (lookup-blocks bits hsh fail) (let recur ((bs bits) (r null)) (if (null? bs) (reverse r) (let-values (((bs′ tl) (split-at bs 7))) (let ((d (hash-ref hsh bs′ (λ () (fail (list 'not-found bs′)))))) (recur tl (cons d r)))))))   (define (extract-blocks b fail) (let*-values (((e-l-m-r-e) (map is-#? (string->list (string-trim b)))) ((_) (unless (= (length e-l-m-r-e) (+ 3 (* 7 6) 5 (* 7 6) 3)) (fail 'wrong-length))) ((e l-m-r-e) (split-at e-l-m-r-e 3)) ((_) (unless (equal? e '(#t #f #t)) (fail 'left-sentinel))) ((l-m-r e) (split-at-right l-m-r-e 3)) ((_) (unless (equal? e '(#t #f #t)) (fail 'right-sentinel))) ((l m-r) (split-at l-m-r 42)) ((m r) (split-at m-r 5)) ((_) (unless (equal? m '(#f #t #f #t #f)) (fail 'mid-sentinel)))) (values l r)))   (define (upc-checksum? ds) (zero? (modulo (for/sum ((m (in-cycle '(3 1))) (d ds)) (* m d)) 10)))   (define (lookup-digits l r fail (transform values)) (let/ec fail-lookups (define ds (append (lookup-blocks l left-digits (λ _ (fail-lookups #f))) (lookup-blocks r right-digits (λ _ (fail-lookups #f))))) (if (upc-checksum? ds) (transform ds) (fail (list 'checksum (transform ds))))))   (define (decode-upc barcode upside-down fail) (define-values (l r) (extract-blocks barcode fail)) (or (lookup-digits l r fail) (lookup-digits (reverse r) (reverse l) fail upside-down)))   (define (report-upc barcode) (displayln (decode-upc barcode (λ (v) (cons 'upside-down v)) (λ (e) (format "invalid: ~s" e)))))   (define (UPC) (for-each report-upc '(" # # # ## # ## # ## ### ## ### ## #### # # # ## ## # # ## ## ### # ## ## ### # # # " " # # # ## ## # #### # # ## # ## # ## # # # ### # ### ## ## ### # # ### ### # # # " " # # # # # ### # # # # # # # # # # ## # ## # ## # ## # # #### ### ## # # " " # # ## ## ## ## # # # # ### # ## ## # # # ## ## # ### ## ## # # #### ## # # # " " # # ### ## # ## ## ### ## # ## # # ## # # ### # ## ## # # ### # ## ## # # # " " # # # # ## ## # # # # ## ## # # # # # #### # ## # #### #### # # ## # #### # # " " # # # ## ## # # ## ## # ### ## ## # # # # # # # # ### # # ### # # # # # " " # # # # ## ## # # ## ## ### # # # # # ### ## ## ### ## ### ### ## # ## ### ## # # " " # # ### ## ## # # #### # ## # #### # #### # # # # # ### # # ### # # # ### # # # " " # # # #### ## # #### # # ## ## ### #### # # # # ### # ### ### # # ### # # # ### # # "  ; first element again, with corrupted second digit " # # # ## # ## # ## ### ## ### ## #### # # # ## ## # # ## ## ### # ## ## ### # # # ")))   (module+ main (UPC))
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
#Wren
Wren
import "io" for File import "/ioutil" for FileUtil import "/dynamic" for Tuple import "/str" for Str   var fields = ["favouriteFruit", "needsPeeling", "seedsRemoved", "numberOfBananas", "numberOfStrawberries"] var ConfigData = Tuple.create("ConfigData", fields)   var updateConfigFile = Fn.new { |fileName, cData| var lines = File.read(fileName).trimEnd().split(FileUtil.lineBreak) var tempFileName = "temp_%(fileName)" var out = File.create(tempFileName) var hadFruit = false var hadPeeling = false var hadSeeds = false var hadBananas = false var hadStrawberries = false   for (line in lines) { var cont = false if (line.isEmpty || line[0] == "#") { out.writeBytes(line + "\n") cont = true } if (!cont) { var ln = Str.upper(line.trimStart(";").trim()) if (!ln.isEmpty) { if (ln.take(14).join() == "FAVOURITEFRUIT") { if (!hadFruit) { hadFruit = true out.writeBytes("FAVOURITEFRUIT %(cData.favouriteFruit)\n") } } else if (ln.take(12).join() == "NEEDSPEELING") { if (!hadPeeling) { hadPeeling = true if (cData.needsPeeling) { out.writeBytes("NEEDSPEELING\n") } else { out.writeBytes("; NEEDSPEELING\n") } } } else if (ln.take(12).join() == "SEEDSREMOVED") { if (!hadSeeds) { hadSeeds = true if (cData.seedsRemoved) { out.writeBytes("SEEDSREMOVED\n") } else { out.writeBytes("; SEEDSREMOVED\n") } } } else if (ln.take(15).join() == "NUMBEROFBANANAS") { if (!hadBananas) { hadBananas = true out.writeBytes("NUMBEROFBANANAS %(cData.numberOfBananas)\n") } } else if (ln.take(20).join() == "NUMBEROFSTRAWBERRIES") { if (!hadStrawberries) { hadStrawberries = true out.writeBytes("NUMBEROFSTRAWBERRIES %(cData.numberOfStrawberries)\n") } } } } }   if (!hadFruit) { out.writeBytes("FAVOURITEFRUIT %(cData.favouriteFruit)\n") }   if (!hadPeeling) { if (cData.needsPeeling) { out.writeBytes("NEEDSPEELING\n") } else { out.writeBytes("; NEEDSPEELING\n") } }   if (!hadSeeds) { if (cData.seedsRemoved) { out.writeBytes("SEEDSREMOVED\n") } else { out.writeBytes("; SEEDSREMOVED\n") } }   if (!hadBananas) { out.writeBytes("NUMBEROFBANANAS %(cData.numberOfBananas)\n") }   if (!hadStrawberries) { out.writeBytes("NUMBEROFSTRAWBERRIES %(cData.numberOfStrawberries)\n") }   out.close() FileUtil.move(tempFileName, fileName, true) }   var fileName = "config.txt" var cData = ConfigData.new("banana", false, true, 1024, 62000) updateConfigFile.call(fileName, cData)
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
#Lasso
Lasso
#!/usr/bin/lasso9   define read_input(prompt::string) => {   local(string)   // display prompt stdout(#prompt) // the following bits wait until the terminal gives you back a line of input while(not #string or #string -> size == 0) => { #string = file_stdin -> readsomebytes(1024, 1000) } #string -> replace(bytes('\n'), bytes(''))   return #string -> asstring   }   local( string, number )   // get string #string = read_input('Enter the string: ')   // get number #number = integer(read_input('Enter the number: '))   // deliver the result stdoutnl(#string + ' (' + #string -> type + ') | ' + #number + ' (' + #number -> type + ')')
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
#Liberty_BASIC
Liberty BASIC
Input "Enter a string. ";string$ Input "Enter the value 75000.";num
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
#Python
Python
import Tkinter,tkSimpleDialog   root = Tkinter.Tk() root.withdraw()   number = tkSimpleDialog.askinteger("Integer", "Enter a Number") string = tkSimpleDialog.askstring("String", "Enter a 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
#Quackery
Quackery
$ \ import tkinter import tkinter.simpledialog as tks   root = tkinter.Tk() root.withdraw()   to_stack(tks.askinteger("Integer", "Enter a Number")) string_to_stack(tks.askstring("String", "Enter a String"))   \ python   swap echo cr echo$
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.
#Swift
Swift
import Foundation   func encode(_ scalar: UnicodeScalar) -> Data { return Data(String(scalar).utf8) }   func decode(_ data: Data) -> UnicodeScalar? { guard let string = String(data: data, encoding: .utf8) else { assertionFailure("Failed to convert data to a valid String") return nil } assert(string.unicodeScalars.count == 1, "Data should contain one scalar!") return string.unicodeScalars.first }   for scalar in "AöЖ€𝄞".unicodeScalars { let bytes = encode(scalar) let formattedBytes = bytes.map({ String($0, radix: 16)}).joined(separator: " ") let decoded = decode(bytes)! print("character: \(decoded), code point: U+\(String(scalar.value, radix: 16)), \tutf-8: \(formattedBytes)") }  
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.
#Tcl
Tcl
proc encoder int { set u [format %c $int] set bytes {} foreach byte [split [encoding convertto utf-8 $u] ""] { lappend bytes [format %02X [scan $byte %c]] } return $bytes } proc decoder bytes { set str {} foreach byte $bytes { append str [format %c [scan $byte %x]] } return [encoding convertfrom utf-8 $str] } foreach test {0x0041 0x00f6 0x0416 0x20ac 0x1d11e} { set res $test lappend res [encoder $test] -> [decoder [encoder $test]] puts $res }
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
#Pike
Pike
Protocols.HTTP.uri_encode( "http://foo bar/" );
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
#Powershell
Powershell
  [uri]::EscapeDataString('http://foo bar/')   http%3A%2F%2Ffoo%20bar%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
#Mathematica.2FWolfram_Language
Mathematica/Wolfram Language
x=value assign a value to the variable x x=y=value assign a value to both x and y x=. or Clear[x] remove any value assigned to x lhs=rhs (immediate assignment) rhs is evaluated when the assignment is made lhs:=rhs (delayed assignment) rhs is evaluated each time the value of lhs is requested
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
#MATLAB_.2F_Octave
MATLAB / Octave
a = 4; % declare variable and initialize double value, s = 'abc'; % string i8 = int8(5); % signed byte u8 = uint8(5); % unsigned byte i16 = int16(5); % signed 2 byte u16 = uint16(5); % unsigned 2 byte integer i32 = int32(5); % signed 4 byte integer u32 = uint32(5);% unsigned 4 byte integers i64 = int64(5); % signed 8 byte integer u64 = uint64(5);% unsigned 8 byte integer f32 = float32(5); % single precision floating point number f64 = float64(5); % double precision floating point number , float 64 is the default data type.   c = 4+5i; % complex number colvec = [1;2;4]; % column vector crowvec = [1,2,4]; % row vector m = [1,2,3;4,5,6]; % matrix with size 2x3
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
#Visual_Basic
Visual Basic
Option Explicit '-------------------------------------------------- Sub varargs(ParamArray a()) Dim n As Long, m As Long Debug.Assert VarType(a) = (vbVariant Or vbArray) For n = LBound(a) To UBound(a) If IsArray(a(n)) Then For m = LBound(a(n)) To UBound(a(n)) Debug.Print a(n)(m) Next m Else Debug.Print a(n) End If Next End Sub '-------------------------------------------------- Sub Main() Dim v As Variant   Debug.Print "call 1" varargs 1, 2, 3   Debug.Print "call 2" varargs 4, 5, 6, 7, 8   v = Array(9, 10, 11) Debug.Print "call 3" varargs v   ReDim v(0 To 2) v(0) = 12 v(1) = 13 v(2) = 14 Debug.Print "call 4" varargs 11, v   Debug.Print "call 5" varargs v(2), v(1), v(0), 11   End Sub
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
#Vlang
Vlang
fn print_all(things ...string) { for x in things { println(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
#Ksh
Ksh
  #!/bin/ksh   # Vector products # # dot product (a scalar quantity) A • B = a1b1 + a2b2 + a3b3 + ... # # cross product (a vector quantity) A x B = (a2b3 - a3b2, a3b1 - a1b3, a1b2 - a2b1) # # scalar triple product (a scalar quantity) A • (B x C) # # vector triple product (a vector quantity) A x (B x C)   # # Variables: # typeset -a A=( 3 4 5 ) typeset -a B=( 4 3 5 ) typeset -a C=( -5 -12 -13 )   # # Functions: #   # # Function _dotprod(vec1, vec2) - Return the (scalar) dot product of 2 vectors # function _dotprod { typeset _vec1 ; nameref _vec1="$1" # Input vector 1 typeset _vec2 ; nameref _vec2="$2" # Input vector 2 typeset _i ; typeset -si _i typeset _dotp ; integer _dotp=0   for ((_i=0; _i<${#_vec1[*]}; _i++)); do (( _dotp+=(_vec1[_i] * _vec2[_i]) )) done echo ${_dotp} }   # # Function _crossprod(vec1, vec2, vec) - Return the (vector) cross product of 2 vectors # function _crossprod { typeset _vec1 ; nameref _vec1="$1" # Input vector 1 typeset _vec2 ; nameref _vec2="$2" # Input vector 2 typeset _vec3 ; nameref _vec3="$3" # Output vector   _vec3+=( $(( _vec1[1]*_vec2[2] - _vec1[2]*_vec2[1] )) ) _vec3+=( $(( _vec1[2]*_vec2[0] - _vec1[0]*_vec2[2] )) ) _vec3+=( $(( _vec1[0]*_vec2[1] - _vec1[1]*_vec2[0] )) ) }   # # Function _scal3prod(vec1, vec2, vec3) - Return the (scalar) scalar triple product of 3 vectors # function _scal3prod { typeset _vec1 ; nameref _vec1="$1" # Input vector 1 typeset _vec2 ; nameref _vec2="$2" # Input vector 2 typeset _vec3 ; nameref _vec3="$3" # Input vector 3 typeset _vect ; typeset -a _vect # temp vector   _crossprod _vec2 _vec3 _vect # (B x C) echo $(_dotprod _vec1 _vect) # A • (B x C)   }   # # Function _vect3prod(vec1, vec2, vec3, vec) - Return the (vector) vector triple product of 3 vectors # function _vect3prod { typeset _vec1 ; nameref _vec1="$1" # Input vector 1 typeset _vec2 ; nameref _vec2="$2" # Input vector 2 typeset _vec3 ; nameref _vec3="$3" # Input vector 3 typeset _vec4 ; nameref _vec4="$4" # Output vector typeset _vect ; typeset -a _vect # temp vector   _crossprod _vec2 _vec3 _vect # (B x C) _crossprod _vec1 _vect _vec4 # A x (B x C) }   ###### # main # ######   print "The dot product A • B = $(_dotprod A B)"   typeset -a arr _crossprod A B arr print "The cross product A x B = ( ${arr[@]} )"   print "The scalar triple product A • (B x C) = $(_scal3prod A B C)"   typeset -m crossprod=arr ; typeset -a arr _vect3prod A B C arr print "The vector triple product A x (B x C) = ( ${arr[@]} )"  
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
#VBScript
VBScript
'http://rosettacode.org/wiki/Van_der_Corput_sequence 'Van der Corput Sequence fucntion call = VanVanDerCorput(number,base)   Base2 = "0" : Base3 = "0" : Base4 = "0" : Base5 = "0" Base6 = "0" : Base7 = "0" : Base8 = "0" : Base9 = "0"   l = 1 h = 1 Do Until l = 9 'Set h to the value of l after each function call 'as it sets it to 0 - see lines 37 to 40. Base2 = Base2 & ", " & VanDerCorput(h,2) : h = l Base3 = Base3 & ", " & VanDerCorput(h,3) : h = l Base4 = Base4 & ", " & VanDerCorput(h,4) : h = l Base5 = Base5 & ", " & VanDerCorput(h,5) : h = l Base6 = Base6 & ", " & VanDerCorput(h,6) : h = l l = l + 1 Loop   WScript.Echo "Base 2: " & Base2 WScript.Echo "Base 3: " & Base3 WScript.Echo "Base 4: " & Base4 WScript.Echo "Base 5: " & Base5 WScript.Echo "Base 6: " & Base6   'Van der Corput Sequence Function VanDerCorput(n,b) k = RevString(Dec2BaseN(n,b)) For i = 1 To Len(k) VanDerCorput = VanDerCorput + (CLng(Mid(k,i,1)) * b^-i) Next End Function   'Decimal to Base N Conversion Function Dec2BaseN(q,c) Dec2BaseN = "" Do Until q = 0 Dec2BaseN = CStr(q Mod c) & Dec2BaseN q = Int(q / c) Loop End Function   'Reverse String Function RevString(s) For j = Len(s) To 1 Step -1 RevString = RevString & Mid(s,j,1) Next 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
#Visual_Basic_.NET
Visual Basic .NET
Module Module1   Function ToBase(n As Integer, b As Integer) As String Dim result = "" If b < 2 Or b > 16 Then Throw New ArgumentException("The base is out of range") End If   Do Dim remainder = n Mod b result = "0123456789ABCDEF"(remainder) + result n = n \ b Loop While n > 0   Return result End Function   Sub Main() For b = 2 To 5 Console.WriteLine("Base = {0}", b) For i = 0 To 12 Dim s = "." + ToBase(i, b) Console.Write("{0,6} ", s) Next Console.WriteLine() Console.WriteLine() Next End Sub   End Module
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".
#ooRexx
ooRexx
/* Rexx */ X = 0 url. = '' X = X + 1; url.0 = X; url.X = 'http%3A%2F%2Ffoo%20bar%2F' X = X + 1; url.0 = X; url.X = 'mailto%3A%22Ivan%20Aim%22%20%3Civan%2Eaim%40email%2Ecom%3E' X = X + 1; url.0 = X; url.X = '%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'   Do u_ = 1 to url.0 Say url.u_ Say DecodeURL(url.u_) Say End u_   Exit   DecodeURL: Procedure   Parse Arg encoded decoded = '' PCT = '%'   Do label e_ while encoded~length() > 0 Parse Var 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 Nop End encoded = tail End e_   Return decoded
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".
#Perl
Perl
sub urldecode { my $s = shift; $s =~ tr/\+/ /; $s =~ s/\%([A-Fa-f0-9]{2})/pack('C', hex($1))/eg; return $s; }   print urldecode('http%3A%2F%2Ffoo+bar%2F')."\n";  
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.
#Raku
Raku
sub decode_UPC ( Str $line ) { constant @patterns1 = ' ## #', ' ## #', ' # ##', ' #### #', ' # ##', ' ## #', ' # ####', ' ### ##', ' ## ###', ' # ##'; constant @patterns2 = @patterns1».trans( '#' => ' ', ' ' => '#' );   constant %pattern_to_digit_1 = @patterns1.antipairs; constant %pattern_to_digit_2 = @patterns2.antipairs;   constant $re = / ^ '# #' (@patterns1) ** 6 ' # # ' (@patterns2) ** 6 '# #' $ /;   $line.trim ~~ $re orelse return;   my @digits = flat %pattern_to_digit_1{ $0».Str }, %pattern_to_digit_2{ $1».Str };   return unless ( @digits Z* ( |(3,1) xx * ) ).sum %% 10;   return @digits.join; }   my @lines = ' # # # ## # ## # ## ### ## ### ## #### # # # ## ## # # ## ## ### # ## ## ### # # # ', ' # # # ## ## # #### # # ## # ## # ## # # # ### # ### ## ## ### # # ### ### # # # ', ' # # # # # ### # # # # # # # # # # ## # ## # ## # ## # # #### ### ## # # ', ' # # ## ## ## ## # # # # ### # ## ## # # # ## ## # ### ## ## # # #### ## # # # ', ' # # ### ## # ## ## ### ## # ## # # ## # # ### # ## ## # # ### # ## ## # # # ', ' # # # # ## ## # # # # ## ## # # # # # #### # ## # #### #### # # ## # #### # # ', ' # # # ## ## # # ## ## # ### ## ## # # # # # # # # ### # # ### # # # # # ', ' # # # # ## ## # # ## ## ### # # # # # ### ## ## ### ## ### ### ## # ## ### ## # # ', ' # # ### ## ## # # #### # ## # #### # #### # # # # # ### # # ### # # # ### # # # ', ' # # # #### ## # #### # # ## ## ### #### # # # # ### # ### ### # # ### # # # ### # # ', ; for @lines -> $line { say decode_UPC($line) // decode_UPC($line.flip) // 'Invalid'; }
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
#LIL
LIL
# User input/text, in LIL write "Enter a string: " set text [readline]   set num 0 while {[canread] && $num != 75000} { write "Enter the number 75000: " set num [readline] }   print $text print $num
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
#Logo
Logo
make "input readlist  ; in: string 75000 show map "number? :input  ; [false true]   make "input readword  ; in: 75000 show :input + 123  ; 75123 make "input readword  ; in: string 75000 show :input  ; string 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
#R
R
  library(gWidgets) options(guiToolkit="RGtk2") ## using gWidgtsRGtk2   w <- gwindow("Enter a string and a number") lyt <- glayout(cont=w) lyt[1,1] <- "Enter a string" lyt[1,2] <- gedit("", cont=lyt) lyt[2,1] <- "Enter 75000" lyt[2,2] <- gedit("", cont=lyt) lyt[3,2] <- gbutton("validate", cont=lyt, handler=function(h,...) { txt <- svalue(lyt[1,2]) x <- svalue(lyt[2,2]) x <- gsub(",", "", x) x <- as.integer(x)   if(nchar(txt) > 0 && x == 75000) gmessage("Congratulations, you followed directions", parent=w) else gmessage("You failed this simple task", parent=w) })  
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
#Racket
Racket
  #lang racket (require racket/gui)   (define str (get-text-from-user "Hi" "Enter a string")) (message-box "Hi" (format "You entered: ~a" str))   (define n (get-text-from-user "Hi" "Enter a number")) (message-box "Hi" (format "You entered: ~a" (or (string->number n) "bogus 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.
#VBA
VBA
Private Function unicode_2_utf8(x As Long) As Byte() Dim y() As Byte Dim r As Long Select Case x Case 0 To &H7F ReDim y(0) y(0) = x Case &H80 To &H7FF ReDim y(1) y(0) = 192 + x \ 64 y(1) = 128 + x Mod 64 Case &H800 To &H7FFF ReDim y(2) y(2) = 128 + x Mod 64 r = x \ 64 y(1) = 128 + r Mod 64 y(0) = 224 + r \ 64 Case 32768 To 65535 '&H8000 To &HFFFF equals in VBA as -32768 to -1 ReDim y(2) y(2) = 128 + x Mod 64 r = x \ 64 y(1) = 128 + r Mod 64 y(0) = 224 + r \ 64 Case &H10000 To &H10FFFF ReDim y(3) y(3) = 128 + x Mod 64 r = x \ 64 y(2) = 128 + r Mod 64 r = r \ 64 y(1) = 128 + r Mod 64 y(0) = 240 + r \ 64 Case Else MsgBox "what else?" & x & " " & Hex(x) End Select unicode_2_utf8 = y End Function Private Function utf8_2_unicode(x() As Byte) As Long Dim first As Long, second As Long, third As Long, fourth As Long Dim total As Long Select Case UBound(x) - LBound(x) Case 0 'one byte If x(0) < 128 Then total = x(0) Else MsgBox "highest bit set error" End If Case 1 'two bytes and assume first byte is leading byte If x(0) \ 32 = 6 Then first = x(0) Mod 32 If x(1) \ 64 = 2 Then second = x(1) Mod 64 Else MsgBox "mask error" End If Else MsgBox "leading byte error" End If total = 64 * first + second Case 2 'three bytes and assume first byte is leading byte If x(0) \ 16 = 14 Then first = x(0) Mod 16 If x(1) \ 64 = 2 Then second = x(1) Mod 64 If x(2) \ 64 = 2 Then third = x(2) Mod 64 Else MsgBox "mask error last byte" End If Else MsgBox "mask error middle byte" End If Else MsgBox "leading byte error" End If total = 4096 * first + 64 * second + third Case 3 'four bytes and assume first byte is leading byte If x(0) \ 8 = 30 Then first = x(0) Mod 8 If x(1) \ 64 = 2 Then second = x(1) Mod 64 If x(2) \ 64 = 2 Then third = x(2) Mod 64 If x(3) \ 64 = 2 Then fourth = x(3) Mod 64 Else MsgBox "mask error last byte" End If Else MsgBox "mask error third byte" End If Else MsgBox "mask error second byte" End If Else MsgBox "mask error leading byte" End If total = CLng(262144 * first + 4096 * second + 64 * third + fourth) Case Else MsgBox "more bytes than expected" End Select utf8_2_unicode = total End Function Public Sub program() Dim cp As Variant Dim r() As Byte, s As String cp = [{65, 246, 1046, 8364, 119070}] '[{&H0041,&H00F6,&H0416,&H20AC,&H1D11E}] Debug.Print "ch unicode UTF-8 encoded decoded" For Each cpi In cp r = unicode_2_utf8(CLng(cpi)) On Error Resume Next s = CStr(Hex(cpi)) Debug.Print ChrW(cpi); String$(10 - Len(s), " "); s, If Err.Number = 5 Then Debug.Print "?"; String$(10 - Len(s), " "); s, s = "" For Each yz In r s = s & CStr(Hex(yz)) & " " Next yz Debug.Print String$(13 - Len(s), " "); s; s = CStr(Hex(utf8_2_unicode(r))) Debug.Print String$(8 - Len(s), " "); s Next cpi End Sub
http://rosettacode.org/wiki/URL_encoding
URL encoding
Task Provide a function or mechanism to convert a provided string into URL encoding representation. In URL encoding, special characters, control characters and extended characters are converted into a percent symbol followed by a two digit hexadecimal code, So a space character encodes into %20 within the string. For the purposes of this task, every character except 0-9, A-Z and a-z requires conversion, so the following characters all require conversion by default: ASCII control codes (Character ranges 00-1F hex (0-31 decimal) and 7F (127 decimal). ASCII symbols (Character ranges 32-47 decimal (20-2F hex)) ASCII symbols (Character ranges 58-64 decimal (3A-40 hex)) ASCII symbols (Character ranges 91-96 decimal (5B-60 hex)) ASCII symbols (Character ranges 123-126 decimal (7B-7E hex)) Extended characters with character codes of 128 decimal (80 hex) and above. Example The string "http://foo bar/" would be encoded as "http%3A%2F%2Ffoo%20bar%2F". Variations Lowercase escapes are legal, as in "http%3a%2f%2ffoo%20bar%2f". Some standards give different rules: RFC 3986, Uniform Resource Identifier (URI): Generic Syntax, section 2.3, says that "-._~" should not be encoded. HTML 5, section 4.10.22.5 URL-encoded form data, says to preserve "-._*", and to encode space " " to "+". The options below provide for utilization of an exception string, enabling preservation (non encoding) of particular characters to meet specific standards. Options It is permissible to use an exception string (containing a set of symbols that do not need to be converted). However, this is an optional feature and is not a requirement of this task. Related tasks   URL decoding   URL parser
#PureBasic
PureBasic
URL$ = URLEncoder("http://foo bar/")
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
#Python
Python
import urllib s = 'http://foo/bar/' s = urllib.quote(s)
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
#Mercury
Mercury
:- func name = string. name = Name :- Name = Title ++ " " ++ Given, Title = "Dr.", Given = "Bob".
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
#Modula-3
Modula-3
MODULE Foo EXPORTS Main;   IMPORT IO, Fmt;   VAR foo: INTEGER := 5; (* foo is global (to the module). *)   PROCEDURE Foo() = VAR bar: INTEGER := 10; (* bar is local to the procedure Foo. *) BEGIN IO.Put("foo + bar = " & Fmt.Int(foo + bar) & "\n"); END Foo;   BEGIN Foo(); END Foo.
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
#Vorpal
Vorpal
self.f = method(x, y[ ], z){ x.print() for(i = 0, i < y.size(), i = i + 1){ ('[' + y[i] + ']').print() } z.print() }   self.f(1, 2, 3) '---'.print() self.f(1, 2, 3, 4) '---'.print() self.f(1, 2)
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
#Wren
Wren
var printArgs = Fn.new { |args| args.each { |arg| System.print(arg) } }   printArgs.call(["Mary", "had", "3", "little", "lambs"])
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
#Lambdatalk
Lambdatalk
  {def dotProduct {lambda {:a :b} {+ {* {A.get 0 :a} {A.get 0 :b}} {* {A.get 1 :a} {A.get 1 :b}} {* {A.get 2 :a} {A.get 2 :b}}}}} -> dotProduct   {def crossProduct {lambda {:a :b} {A.new {- {* {A.get 1 :a} {A.get 2 :b}} {* {A.get 2 :a} {A.get 1 :b}}} {- {* {A.get 2 :a} {A.get 0 :b}} {* {A.get 0 :a} {A.get 2 :b}}} {- {* {A.get 0 :a} {A.get 1 :b}} {* {A.get 1 :a} {A.get 0 :b}}} }}} -> crossProduct   {def A {A.new 3 4 5}} -> A = [3,4,5] {def B {A.new 4 3 5}} -> B = [4,3,5] {def C {A.new -5 -12 -13}} -> C = [4,3,5]   A.B  : {dotProduct {A} {B}} -> 49 AxB  : {crossProduct {A} {B}} -> [5,5,-7] A.(BxC) : {dotProduct {A} {crossProduct {B} {C}}} -> 6 Ax(BxC) : {crossProduct {A} {crossProduct {B} {C}}} -> [-267,204,-3]  
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
#Vlang
Vlang
fn v2(nn u32) f64 { mut n:=nn mut r := f64(0) mut p := .5 for n > 0 { if n&1 == 1 { r += p } p *= .5 n >>= 1 } return r }   fn new_v(base u32) fn(u32) f64 { invb := 1 / f64(base) return fn[base,invb](nn u32) f64 { mut n:=nn mut r := f64(0) mut p := invb for n > 0 { r += p * f64(n%base) p *= invb n /= base } return r } }   fn main() { println("Base 2:") for i := u32(0); i < 10; i++ { println('$i ${v2(i)}') } println("Base 3:") v3 := new_v(3) for i := u32(0); i < 10; i++ { println('$i ${v3(i)}') } }
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
#Wren
Wren
var v2 = Fn.new { |n| var p = 0.5 var r = 0 while (n > 0) { if (n%2 == 1) r = r + p p = p / 2 n = (n/2).floor } return r }   var newV = Fn.new { |base| var invb = 1 / base return Fn.new { |n| var p = invb var r = 0 while (n > 0) { r = r + p*(n%base) p = p * invb n = (n/base).floor } return r } }   System.print("Base 2:") for (i in 0..9) System.print("%(i) -> %(v2.call(i))")   System.print("\nBase 3:") var v3 = newV.call(3) for (i in 0..9) System.print("%(i) -> %(v3.call(i))")
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".
#Phix
Phix
-- -- demo\rosetta\decode_url.exw -- =========================== -- with javascript_semantics function decode_url(string s) integer skip = 0 string res = "" for i=1 to length(s) do if skip then skip -= 1 else integer ch = s[i] if ch='%' then sequence scanres = {} if i+2<=length(s) then scanres = scanf("#"&s[i+1..i+2],"%x") end if if length(scanres)!=1 then return "decode error" end if skip = 2 ch = scanres[1][1] elsif ch='+' then ch = ' ' end if res &= ch end if end for return res end function printf(1,"%s\n",{decode_url("http%3A%2F%2Ffoo%20bar%2F")}) printf(1,"%s\n",{decode_url("google.com/search?q=%60Abdu%27l-Bah%C3%A1")}) {} = wait_key()
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.
#REXX
REXX
/*REXX program to read/interpret UPC symbols and translate them to a numberic string.*/ #.0= ' ## #' #.1= ' ## #' #.2= ' # ##' #.3= ' #### #' #.4= ' # ##' #.5= ' ## #' #.6= ' # ####' #.7= ' ### ##' #.8= ' ## ###' /* [↓] right─sided UPC digits.*/ #.9= ' # ##' ; do i=0 for 10; ##.i= translate(#.i, ' #', "# ") end /*i*/ say center('UPC', 14, "─") ' ---'copies(1234567, 6)"-----"copies(1234567, 6)'---' @.=. @.1 = ' # # # ## # ## # ## ### ## ### ## #### # # # ## ## # # ## ## ### # ## ## ### # # # ' @.2 = ' # # # ## ## # #### # # ## # ## # ## # # # ### # ### ## ## ### # # ### ### # # # ' @.3 = ' # # # # # ### # # # # # # # # # # ## # ## # ## # ## # # #### ### ## # # ' @.4 = ' # # ## ## ## ## # # # # ### # ## ## # # # ## ## # ### ## ## # # #### ## # # # ' @.5 = ' # # ### ## # ## ## ### ## # ## # # ## # # ### # ## ## # # ### # ## ## # # # ' @.6 = ' # # # # ## ## # # # # ## ## # # # # # #### # ## # #### #### # # ## # #### # # ' @.7 = ' # # # ## ## # # ## ## # ### ## ## # # # # # # # # ### # # ### # # # # # ' @.8 = ' # # # # ## ## # # ## ## ### # # # # # ### ## ## ### ## ### ### ## # ## ### ## # # ' @.9 = ' # # ### ## ## # # #### # ## # #### # #### # # # # # ### # # ### # # # ### # # # ' @.10= ' # # # #### ## # #### # # ## ## ### #### # # # # ### # ### ### # # ### # # # ### # ' ends= '# #' /*define ENDS literal const*/ do j=1 while @.j\==.; $= @.j txt= /*initialize TXT variable*/ if left($, 9)\='' | right($, 9)\='' then txt= 'bad blanks' $= strip($); $$= $ /*elide blanks at ends of $*/ L= length($) /*obtain length of $ string*/ if left($, 3) \==ends | right($, 3) \==ends then txt= 'bad fence' if L \== 95 & txt=='' then txt= 'bad length' $= substr($, 4, L - length(ends)*2) /*elide "ends". */ $= delstr($, length($) % 2 - 1, 5) /* " middle. */ sum= 0 /*initialize SUM*/ if txt=='' then do k=1 for 12; parse var $ x +7 $ /*get UPC digit.*/ do d=0 for 10; if x==#.d | x==##.d then leave /*valid digit? */ end /*d*/ if d==10 & k \==12 then do; txt= 'reversed' ; leave; end if d==10 then do; txt= 'bad digit'; leave; end if k // 2 then sum= sum + d * 3 /*mult. by 3. */ else sum= sum + d /* " " 1. */ txt= txt || d end /*k*/   if left(txt,1)\=="b" then if sum//10\==0 then txt= 'bad checksum' /*invalid sum? */ say center( strip(txt), 15) ' ' $$ /*show chksum (or err msg) with the UPC*/ end /*j*/ /*stick a fork in it, we're all done. */
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
#Logtalk
Logtalk
  :- object(user_input).   :- public(test/0). test :- repeat, write('Enter an integer: '), read(Integer), integer(Integer), !, repeat, write('Enter an atom: '), read(Atom), atom(Atom), !.   :- end_object.  
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
#LOLCODE
LOLCODE
HAI 1.4 I HAS A string GIMMEH string I HAS A number GIMMEH number BTW converts number input to an integer MAEK number A NUMBR KTHXBYE  
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
#Raku
Raku
use GTK::Simple; use GTK::Simple::App;   my GTK::Simple::App $app .= new( title => 'User Interaction' );   $app.border-width = 20;   $app.set-content( GTK::Simple::VBox.new( my $ = GTK::Simple::Label.new( text => 'Enter a string.' ), my $str = GTK::Simple::Entry.new, my $string = GTK::Simple::Label.new, my $ = GTK::Simple::Label.new( text => 'Enter the number 75000' ), my $val = GTK::Simple::Entry.new, my $correct = GTK::Simple::Label.new, ) );   $str.changed.tap: { $string.text = "You entered: { $str.text }" }   $val.changed.tap: { $correct.text = "That's { 'not' unless $val.text ~~ / ^^ <ws> 75000 <ws> $$ / } 75000!" }   $app.run;
http://rosettacode.org/wiki/UTF-8_encode_and_decode
UTF-8 encode and decode
As described in UTF-8 and in Wikipedia, UTF-8 is a popular encoding of (multi-byte) Unicode code-points into eight-bit octets. The goal of this task is to write a encoder that takes a unicode code-point (an integer representing a unicode character) and returns a sequence of 1-4 bytes representing that character in the UTF-8 encoding. Then you have to write the corresponding decoder that takes a sequence of 1-4 UTF-8 encoded bytes and return the corresponding unicode character. Demonstrate the functionality of your encoder and decoder on the following five characters: Character Name Unicode UTF-8 encoding (hex) --------------------------------------------------------------------------------- A LATIN CAPITAL LETTER A U+0041 41 ö LATIN SMALL LETTER O WITH DIAERESIS U+00F6 C3 B6 Ж CYRILLIC CAPITAL LETTER ZHE U+0416 D0 96 € EURO SIGN U+20AC E2 82 AC 𝄞 MUSICAL SYMBOL G CLEF U+1D11E F0 9D 84 9E Provided below is a reference implementation in Common Lisp.
#Vlang
Vlang
import encoding.hex fn decode(s string) ?[]u8 { return hex.decode(s) }   fn main() { println("${'Char':-7} ${'Unicode':7}\tUTF-8 encoded\tDecoded") for codepoint in [`A`, `ö`, `Ж`, `€`, `𝄞`] { encoded := codepoint.bytes().hex() decoded := decode(encoded)? println("${codepoint:-7} U+${codepoint:04X}\t${encoded:-12}\t${decoded.bytestr()}") } }
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.
#Wren
Wren
import "/fmt" for Fmt   var utf8_encode = Fn.new { |cp| String.fromCodePoint(cp).bytes.toList }   var utf8_decode = Fn.new { |b| var mbMask = 0x3f // non-first bytes start 10 and carry 6 bits of data var b0 = b[0] if (b0 < 0x80) { return b0 } else if (b0 < 0xe0) { var b2Mask = 0x1f // first byte of a 2-byte encoding starts 110 and carries 5 bits of data return (b0 & b2Mask) << 6 | (b[1] & mbMask) } else if (b0 < 0xf0) { var b3Mask = 0x0f // first byte of a 3-byte encoding starts 1110 and carries 4 bits of data return (b0 & b3Mask) << 12 | (b[1] & mbMask) << 6 | (b[2] & mbMask) } else { var b4Mask = 0x07 // first byte of a 4-byte encoding starts 11110 and carries 3 bits of data return (b0 & b4Mask) << 18 | (b[1] & mbMask) << 12 | (b[2] & mbMask) << 6 | (b[3] & mbMask) } }   var tests = [ ["LATIN CAPITAL LETTER A", 0x41], ["LATIN SMALL LETTER O WITH DIAERESIS", 0xf6], ["CYRILLIC CAPITAL LETTER ZHE", 0x416], ["EURO SIGN", 0x20ac], ["MUSICAL SYMBOL G CLEF", 0x1d11e] ]   System.print("Character Name Unicode UTF-8 encoding (hex)") System.print("---------------------------------------------------------------------------------")   for (test in tests) { var cp = test[1] var bytes = utf8_encode.call(cp) var utf8 = bytes.map { |b| Fmt.Xz(2, b) }.join(" ") var cp2 = utf8_decode.call(bytes) var uni = String.fromCodePoint(cp2) System.print("%(Fmt.s(-11, uni)) %(Fmt.s(-37, test[0])) U+%(Fmt.s(-8, Fmt.Xz(4, cp2))) %(utf8)") }
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
#R
R
URLencode("http://foo bar/")
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
#Racket
Racket
  #lang racket (require net/uri-codec) (uri-encode "http://foo bar/")  
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
#Nanoquery
Nanoquery
// variable definition and initialization/assignment // // variables are initialized when they are defined a = 1 b = 2 c = null   // datatypes // // variables may contain any datatype, and this can be // changed at any time by assigning a new value. they may // also contain native java types var = "a string" var = 123 var = new(Nanoquery.Util.Random) var = new(java.lang.Object)   // scope // // all classes, functions, and control blocks have their // own scope x = 5 for i in range(1, 2) // we can reference 'x' within this loop without issue println x   // we can also define variables that have this loop as their // scope y = 5 end // trying to reference the variable 'y' outside of its scope would result // in a null reference exception println y //%null reference exception: variable object 'y' has not been defined // at <global>:33     // referencing // // as already demonstrated, variables are referenced by using their // name part1 = "this is " part2 = "a test sentence" println part1 + part2   // other facilities // // variables may be marked for garbage collection in their current // scope using the 'delete' command test_var = "pretend this is a really large object we want to free up" delete test_var
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
#Nim
Nim
var x: int = 3 # Declaration with type specification and initialization.   var y = 3 # Declaration with type inferred to "int".   var z: int # Variable is initialized to 0.   let a = 13 # Immutable variable.   # Using a var block to initialize. var b, c: int = 10 # Two variables initialized to 10 s* = "foobar" # This one is exported.   type Obj = ref object i: int s: string   var obj = Obj(i: 3, s: "abc") # Initialization with an implicit allocation by "new". echo obj.a, " ", obj.s # Equivalent to obj[].a and obj[].s.   proc p = var xloc = 3 echo x # Referencing a global variable.   proc q = echo xloc # Referencing a variable in the enclosing scope.
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
#XLISP
XLISP
(defun print-on-separate-lines (&rest xs) (for-each print xs))   ; test the function:   (print-on-separate-lines 'i 'am 'doing 'a 'great 'work 'so 'that 'i 'cannot 'come 'down)   ; to use it on a list of arguments assembled at run time, first create your list   (define test '(why should the work cease whilst i leave it and come down to you))   ; and then call APPLY:   (apply print-on-separate-lines test)
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
#XPL0
XPL0
include c:\cxpl\codes; \intrinsic 'code' declarations def IntSize=4; \number of bytes in an integer   proc Var(N...); \Display N strings passed as arguments int N; [N:= Reserve(N*IntSize); \reserve space for N string pointers repeat Text(0,N(0)); CrLf(0); \display strings pointed to by N(0) N:= N+IntSize; \point to next string until N=GetHp; \pointing beyond reserved space? ];   Var(4, "Mary", "had", "a", "little")
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
#zkl
zkl
fcn f{vm.arglist.apply2("println")} f("Mary","had","a","little");
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
#Liberty_BASIC
Liberty BASIC
print "Vector products of 3-D vectors"   print "Dot product of 3,4,5 and 4,3,5 is " print DotProduct( "3,4,5", "4,3,5") print "Cross product of 3,4,5 and 4,3,5 is " print CrossProduct$( "3,4,5", "4,3,5") print "Scalar triple product of 3,4,5, 4,3,5 -5, -12, -13 is " print ScalarTripleProduct( "3,4,5", "4,3,5", "-5, -12, -13") print "Vector triple product of 3,4,5, 4,3,5 -5, -12, -13 is " print VectorTripleProduct$( "3,4,5", "4,3,5", "-5, -12, -13")     end   function DotProduct( i$, j$) ix =val( word$( i$, 1, ",")) iy =val( word$( i$, 2, ",")) iz =val( word$( i$, 3, ",")) jx =val( word$( j$, 1, ",")) jy =val( word$( j$, 2, ",")) jz =val( word$( j$, 3, ",")) DotProduct = ix *jx +iy *jy + iz *jz end function   function CrossProduct$( i$, j$) ix =val( word$( i$, 1, ",")) iy =val( word$( i$, 2, ",")) iz =val( word$( i$, 3, ",")) jx =val( word$( j$, 1, ",")) jy =val( word$( j$, 2, ",")) jz =val( word$( j$, 3, ",")) cpx =iy *jz -iz *jy cpy =iz *jx -ix *jz cpz =ix *jy -iy *jx CrossProduct$ =str$( cpx); ","; str$( cpy); ","; str$( cpz) end function   function ScalarTripleProduct( i$, j$, k$)) ScalarTripleProduct =DotProduct( i$, CrossProduct$( j$, k$)) end function   function VectorTripleProduct$( i$, j$, k$)) VectorTripleProduct$ =CrossProduct$( i$, CrossProduct$( j$, k$)) end function END SUB
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
#XPL0
XPL0
include c:\cxpl\codes; \intrinsic 'code' declarations   func real VdC(N); \Return Nth term of van der Corput sequence in base 2 int N; real V, U; [V:= 0.0; U:= 0.5; repeat N:= N/2; if rem(0) then V:= V+U; U:= U/2.0; until N=0; return V; ];   int N; for N:= 0 to 10-1 do [IntOut(0, N); RlOut(0, VdC(N)); CrLf(0)]
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
#zkl
zkl
fcn vdc(n,base=2){ vdc:=0.0; denom:=1; while(n){ reg remainder; denom *= base; n, remainder = n.divr(base); vdc += (remainder.toFloat() / denom); } vdc }
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".
#PHP
PHP
<?php $encoded = "http%3A%2F%2Ffoo%20bar%2F"; $unencoded = rawurldecode($encoded); echo "The unencoded string is $unencoded !\n"; ?>
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".
#PicoLisp
PicoLisp
: (ht:Pack (chop "http%3A%2F%2Ffoo%20bar%2F") T) -> "http://foo bar/"
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.
#Ruby
Ruby
DIGIT_F = { " ## #" => 0, " ## #" => 1, " # ##" => 2, " #### #" => 3, " # ##" => 4, " ## #" => 5, " # ####" => 6, " ### ##" => 7, " ## ###" => 8, " # ##" => 9, }   DIGIT_R = { "### # " => 0, "## ## " => 1, "## ## " => 2, "# # " => 3, "# ### " => 4, "# ### " => 5, "# # " => 6, "# # " => 7, "# # " => 8, "### # " => 9, }   END_SENTINEL = "# #" MID_SENTINEL = " # # "   def decode_upc(s) def decode_upc_impl(input) upc = input.strip if upc.length != 95 then return false end   pos = 0 digits = [] sum = 0   # end sentinel if upc[pos .. pos + 2] == END_SENTINEL then pos += 3 else return false end   # 6 left hand digits for i in 0 .. 5 digit = DIGIT_F[upc[pos .. pos + 6]] if digit == nil then return false else digits.push(digit) sum += digit * [1, 3][digits.length % 2] pos += 7 end end   # mid sentinel if upc[pos .. pos + 4] == MID_SENTINEL then pos += 5 else return false end   # 6 right hand digits for i in 0 .. 5 digit = DIGIT_R[upc[pos .. pos + 6]] if digit == nil then return false else digits.push(digit) sum += digit * [1, 3][digits.length % 2] pos += 7 end end   # end sentinel if upc[pos .. pos + 2] == END_SENTINEL then pos += 3 else return false end   if sum % 10 == 0 then print digits, " " return true else print "Failed Checksum " return false end end   if decode_upc_impl(s) then puts "Rightside Up" elsif decode_upc_impl(s.reverse) then puts "Upside Down" else puts "Invalid digit(s)" end end   def main num = 0   print "%2d: " % [num += 1] decode_upc(" # # # ## # ## # ## ### ## ### ## #### # # # ## ## # # ## ## ### # ## ## ### # # # ")   print "%2d: " % [num += 1] decode_upc(" # # # ## ## # #### # # ## # ## # ## # # # ### # ### ## ## ### # # ### ### # # # ")   print "%2d: " % [num += 1] decode_upc(" # # # # # ### # # # # # # # # # # ## # ## # ## # ## # # #### ### ## # # ")   print "%2d: " % [num += 1] decode_upc(" # # ## ## ## ## # # # # ### # ## ## # # # ## ## # ### ## ## # # #### ## # # # ")   print "%2d: " % [num += 1] decode_upc(" # # ### ## # ## ## ### ## # ## # # ## # # ### # ## ## # # ### # ## ## # # # ")   print "%2d: " % [num += 1] decode_upc(" # # # # ## ## # # # # ## ## # # # # # #### # ## # #### #### # # ## # #### # # ")   print "%2d: " % [num += 1] decode_upc(" # # # ## ## # # ## ## # ### ## ## # # # # # # # # ### # # ### # # # # # ")   print "%2d: " % [num += 1] decode_upc(" # # # # ## ## # # ## ## ### # # # # # ### ## ## ### ## ### ### ## # ## ### ## # # ")   print "%2d: " % [num += 1] decode_upc(" # # ### ## ## # # #### # ## # #### # #### # # # # # ### # # ### # # # ### # # # ")   print "%2d: " % [num += 1] decode_upc(" # # # #### ## # #### # # ## ## ### #### # # # # ### # ### ### # # ### # # # ### # # ") end   main()
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
#Lua
Lua
print('Enter a string: ') s = io.stdin:read() print('Enter a number: ') i = tonumber(io.stdin:read())  
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
#M2000_Interpreter
M2000 Interpreter
  Module CheckIt { Keyboard "75000"+chr$(13) Input "Integer:", A% \\ Input erase keyboard buffer, we can't place in first Keyboard keys for second input Keyboard "Hello World"+Chr$(13) Input "String:", A$ Print A%, A$ } CheckIt  
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
#Rascal
Rascal
import vis::Render; import vis::Figure;   public void UserInput2(){ integer = ""; string = ""; row1 = [text("Enter a string "), textfield("",void(str s){string = s;}), text(str(){return " This input box will give a string by definition.\n You entered <string>";})]; row2 = [text("Enter 75000"), textfield("",void(str v){integer = v;}), text(str(){return " <integer == "75000" ? "Correct" : "Wrong">";})]; render(grid([row1, row2])); }
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
#REBOL
REBOL
rebol [ Title: "Graphical User Input" URL: http://rosettacode.org/wiki/User_Input_-_graphical ]   ; Simple GUI's can be defined with 'layout', a special purpose dialect ; for specifying interfaces. In this case, I describe a gradient ; background with an instruction label, followed by the input fields ; and a validation button. It's possible to check dynamically as the ; user types but I wanted to keep this example as clear as possible.   view layout [   ; You can define new widget styles. Here I create a padded label style ; (so that everything will line up) and a simple indicator light to ; show if there's a problem with an input field.   style label vtext 60 "unlabeled" style indicator box maroon 24x24   backdrop effect [gradient 0x1 black coal]   vtext "Please enter a string, and the number 75000:"   ; By default, GUI widgets are arranged top down. The 'across' word ; starts stacking widgets from left to right. 'return' starts a new ; line -- just like on a typewriter!   across   ; Notice I'm using my new label and indicator styles here. Widgets ; that I need to access later (the input field and the indicator) are ; assigned to variables.   label "string:" s: field 240 si: indicator return   label "number:" n: field 50 ni: indicator return   pad 66 button "validate" [   ; The user may have entered bogus values, so I reset the indicators:   si/color: ni/color: maroon   ; Now I check to see if the values are correct. For the string, I just ; care that there is one. For the integer, I make sure that it ; evaluates to an integer and that it's value is 75000. Because I've ; already set the indicator colour, I don't care the integer ; conversion raises an error or not, so I ignore it if anything goes ; wrong.   if 0 < length? get-face s [si/color: green] error? try [if 75000 = to-integer get-face n [ni/color: green]]   show [si ni] ; Repainting multiple objects at once. ] ]
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.
#zkl
zkl
println("Char Unicode UTF-8"); foreach utf,unicode_int in (T( T("\U41;",0x41), T("\Uf6;",0xf6), T("\U416;",0x416), T("\U20AC;",0x20ac), T("\U1D11E;",0x1d11e))){ utf_int:=utf.reduce(fcn(s,c){ 0x100*s + c.toAsc() },0); char :=unicode_int.toString(-8); // Unicode int to UTF-8 string // UTF-8 bytes to UTF-8 string: char2:=Data(Void,utf_int.toBigEndian(utf_int.len())).text;   println("%s %s %9s  %x".fmt(char,char2,"U+%x".fmt(unicode_int),utf_int)); }
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
#Raku
Raku
my $url = 'http://foo bar/';   say $url.subst(/<-alnum>/, *.ord.fmt("%%%02X"), :g);
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
#REALbasic
REALbasic
  Dim URL As String = "http://foo bar/" URL = EncodeURLComponent(URL) Print(URL)  
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
#Objeck
Objeck
  a : Int; b : Int := 13; c := 7;  
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
#OCaml
OCaml
let x = 28
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
#Lingo
Lingo
a = vector(1,2,3) b = vector(4,5,6)   put a * b -- 32.0000   put a.dot(b) -- 32.0000   put a.cross(b) -- vector( -3.0000, 6.0000, -3.0000 )
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".
#Pike
Pike
  void main() { array encoded_urls = ({ "http%3A%2F%2Ffoo%20bar%2F", "google.com/search?q=%60Abdu%27l-Bah%C3%A1" });     foreach(encoded_urls, string url) { string decoded = Protocols.HTTP.uri_decode( url ); write( string_to_utf8(decoded) +"\n" ); // Assume sink does UTF8 } }  
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".
#PowerShell
PowerShell
  [System.Web.HttpUtility]::UrlDecode("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.
#Wren
Wren
import "/fmt" for Fmt   var digitL = { " ## #": 0, " ## #": 1, " # ##": 2, " #### #": 3, " # ##": 4, " ## #": 5, " # ####": 6, " ### ##": 7, " ## ###": 8, " # ##": 9 }   var digitR = { "### # ": 0, "## ## ": 1, "## ## ": 2, "# # ": 3, "# ### ": 4, "# ### ": 5, "# # ": 6, "# # ": 7, "# # ": 8, "### # ": 9 }   var endSentinel = "# #" // also at start var midSentinel = " # # "   var decodeUpc = Fn.new { |s| var decodeUpcImpl = Fn.new { |input| var upc = input.trim() if (upc.count != 95) return false var pos = 0 var digits = [] var sum = 0 var oneThree = [1, 3]   // end sentinel if (upc[pos..pos+2] == endSentinel) { pos = pos + 3 } else { return false }   // 6 left hand digits for (i in 0..5) { var digit = digitL[upc[pos..pos+6]] if (!digit) return false digits.add(digit) sum = sum + digit * oneThree[digits.count % 2] pos = pos + 7 }   // mid sentinel if (upc[pos..pos+4] == midSentinel) { pos = pos + 5 } else { return false }   // 6 right hand digits for (i in 0..5) { var digit = digitR[upc[pos..pos+6]] if (!digit) return false digits.add(digit) sum = sum + digit * oneThree[digits.count % 2] pos = pos + 7 }   // end sentinel if (upc[pos..pos+2] != endSentinel) return false   if (sum%10 == 0) { System.write("%(digits) ") return true } System.write("Failed Checksum ") return false }   if (decodeUpcImpl.call(s)) { System.print("Rightside Up") } else if (decodeUpcImpl.call(s[-1..0])) { System.print("Upside Down") } else { System.print("Invalid digit(s)") } }   var barcodes = [ " # # # ## # ## # ## ### ## ### ## #### # # # ## ## # # ## ## ### # ## ## ### # # # ", " # # # ## ## # #### # # ## # ## # ## # # # ### # ### ## ## ### # # ### ### # # # ", " # # # # # ### # # # # # # # # # # ## # ## # ## # ## # # #### ### ## # # ", " # # ## ## ## ## # # # # ### # ## ## # # # ## ## # ### ## ## # # #### ## # # # ", " # # ### ## # ## ## ### ## # ## # # ## # # ### # ## ## # # ### # ## ## # # # ", " # # # # ## ## # # # # ## ## # # # # # #### # ## # #### #### # # ## # #### # # ", " # # # ## ## # # ## ## # ### ## ## # # # # # # # # ### # # ### # # # # # ", " # # # # ## ## # # ## ## ### # # # # # ### ## ## ### ## ### ### ## # ## ### ## # # ", " # # ### ## ## # # #### # ## # #### # #### # # # # # ### # # ### # # # ### # # # ", " # # # #### ## # #### # # ## ## ### #### # # # # ### # ### ### # # ### # # # ### # # " ] var n = 0 for (barcode in barcodes) { n = n + 1 Fmt.write("$2d: ", n) decodeUpc.call(barcode) }
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
#MACRO-10
MACRO-10
  TITLE User Input   COMMENT ! User Input ** PDP-10 assembly language (kjx, 2022) Assembler: MACRO-10 Operating system: TOPS-20   This program reads a string (maximum of 80 characters) and a decimal number. The number is checked to be 75000. Invalid input (like entering characters instead of a decimal number) is detected, and an error message is printed in that case. !   SEARCH MONSYM,MACSYM .REQUIRE SYS:MACREL   STDAC.  ;Set standard register names.   STRING: BLOCK 20  ;20 octal words = 80 characters. NUMBER: BLOCK 1  ;1 word for number.    ;;  ;; Execution starts here:  ;;   GO:: RESET%  ;Initialize process.    ;; Print prompt:   HRROI T1,[ASCIZ /Please type a string, 80 chars max.: /] PSOUT%    ;; Read string from terminal:   HRROI T1,STRING  ;Pointer to string-buffer. MOVEI T2,^D80  ;80 characters max. SETZ T3  ;No special ctrl-r prompt. RDTTY%  ;Read from terminal. ERJMP ERROR  ; On error, go to ERROR.    ;; Print second prompt:   NUMI: HRROI T1,[ASCIZ /Please type the decimal number 75000: /] PSOUT%    ;; Input number from terminal:   MOVEI T1,.PRIIN  ;Read from terminal. MOVEI T3,^D10  ;Decimal input. NIN%  ;Input number. ERJMP ERROR  ; On error, go to ERROR.    ;; Make sure number is actually 75000.   CAIE T2,^D75000  ;Compare number... JRST [ HRROI T1,[ASCIZ /Number is not 75000! /] PSOUT%  ; ...complain and JRST NUMI ]  ; try again. MOVEM T2,NUMBER  ;Store number if correct.    ;; Now print out string and number:   HRROI T1,STRING  ;String ptr into T1. PSOUT%  ;Print string.   MOVEI T1,.PRIOU  ;Print on standard output. MOVE T2,NUMBER  ;Load number into T2. MOVEI T3,^D10  ;Decimal output. NOUT%  ;And print the number. ERJMP ERROR  ; On error, go to ERROR.    ;; End program:   HALTF%  ;Halt program. JRST GO  ;Allow for 'continue'-command.    ;;  ;; The following routine prints out an error message,  ;; similar to perror() in C:  ;;   ERROR: MOVEI T1,.PRIOU  ;Standard output. MOVE T2,[.FHSLF,,-1]  ;Own program, last error. SETZ T3,  ;No size-limit on message. ERSTR%  ;Print error-message. JFCL  ; Ignore errors from ERSTR. JFCL  ; dito. HALTF%  ;Halt program. JRST GO  ;Allow for 'continue'-command.   END GO  
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
#Maple
Maple
printf("String:"); string_value := readline(); printf("Integer: "); int_value := parse(readline());
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
#REXX
REXX
/*REXX pgm prompts (using the OS GUI) for a string & then prompts for a specific number.*/ #= 75000 /*the number that must be entered. */ x= N= do while x=' '; say /*string can't be blanks or null string*/ say 'Please enter a string: ' parse pull x if x='' then say '***error*** No string entered.' end /*while x···*/   do while N\=#; say /*the number (below) may be ill formed.*/ say 'Please enter the number:' # parse pull N if datatype(N, 'N') then N= N / 1 /*normalize the number: 007 4.0 +2 */ if N\=# then say '***error*** The number is not correct: ' N. end /*while N···*/ say say 'The string entered is:' x /*echo the values (string and number. */ say 'The number entered is:' N /*stick a fork in it, we're all done. */
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
#Ring
Ring
  Load "guilib.ring"   MyApp = New qApp { num = 0 win1 = new qWidget() { setwindowtitle("Hello World") setGeometry(100,100,370,250)   btn1 = new qpushbutton(win1) { setGeometry(130,200,100,30) settext("Validate") setclickevent("Validate()")}   lineedit1 = new qlineedit(win1) { setGeometry(10,100,250,30) settext("")}   lineedit2 = new qlineedit(win1) { setGeometry(10,150,50,30) settext("0")}   label1 = new qLabel(win1) { setGeometry(270,100,50,30) setText("")}   label2 = new qLabel(win1) { setGeometry(70,150,50,30) setText("")}   label3 = new qLabel(win1) { setGeometry(10,50,250,30) setText("Please enter a string, and the number 75000 :")} show()} exec()}   func Validate lineedit1{temp1 = text()} num1 = isdigit(temp1) if num1 = 0 label1{settext("OK")} else label1{settext("NOT OK")} ok   lineedit2{temp2 = text()} num2 = number(temp2) if num2 = 75000 label2{settext("OK")} else label2{settext("NOT OK")} ok  
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
#REXX
REXX
/* Rexx */ do call testcase say say RFC3986 call testcase RFC3986 say say HTML5 call testcase HTML5 say return end exit   /* -------------------------------------------------------------------------- */ encode: procedure do parse arg url, varn . parse upper var varn variation drop RFC3986 HTML5 opts. = '' opts.RFC3986 = '-._~' opts.HTML5 = '-._*'   rp = '' do while length(url) > 0 parse var url tc +1 url select when datatype(tc, 'A') then do rp = rp || tc end when tc == ' ' then do if variation = HTML5 then rp = rp || '+' else rp = rp || '%' || c2x(tc) end otherwise do if pos(tc, opts.variation) > 0 then do rp = rp || tc end else do rp = rp || '%' || c2x(tc) end end end end   return rp end exit   /* -------------------------------------------------------------------------- */ testcase: procedure do parse arg variation X = 0 url. = '' X = X + 1; url.0 = X; url.X = 'http://foo bar/' X = X + 1; url.0 = X; url.X = 'mailto:"Ivan Aim" <[email protected]>' X = X + 1; url.0 = X; url.X = 'mailto:"Irma User" <[email protected]>' X = X + 1; url.0 = X; url.X = 'http://foo.bar.com/~user-name/_subdir/*~.html'   do i_ = 1 to url.0 say url.i_ say encode(url.i_, variation) end i_   return end  
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
#Oforth
Oforth
import: date   : testVariable | a b c | Date now ->a a println ;
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
#ooRexx
ooRexx
a.=4711 Say 'before sub a.3='a.3 Call sub a. Say ' after sub a.3='a.3 Exit sub: Procedure use Arg a. a.3=3 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
#Lua
Lua
Vector = {} function Vector.new( _x, _y, _z ) return { x=_x, y=_y, z=_z } end   function Vector.dot( A, B ) return A.x*B.x + A.y*B.y + A.z*B.z end   function Vector.cross( A, B ) return { x = A.y*B.z - A.z*B.y, y = A.z*B.x - A.x*B.z, z = A.x*B.y - A.y*B.x } end   function Vector.scalar_triple( A, B, C ) return Vector.dot( A, Vector.cross( B, C ) ) end   function Vector.vector_triple( A, B, C ) return Vector.cross( A, Vector.cross( B, C ) ) end     A = Vector.new( 3, 4, 5 ) B = Vector.new( 4, 3, 5 ) C = Vector.new( -5, -12, -13 )   print( Vector.dot( A, B ) )   r = Vector.cross(A, B ) print( r.x, r.y, r.z )   print( Vector.scalar_triple( A, B, C ) )   r = Vector.vector_triple( A, B, C ) print( r.x, r.y, r.z )
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".
#PureBasic
PureBasic
URL$ = URLDecoder("http%3A%2F%2Ffoo%20bar%2F")   Debug URL$ ; http://foo bar/
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".
#Python
Python
  #Python 2.X import urllib print urllib.unquote("http%3A%2F%2Ffoo%20bar%2F") #Python 3.5+ from urllib.parse import unquote print(unquote('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.
#zkl
zkl
var lhd=Dictionary(), rhd=Dictionary(); [0..].zip(List( "0 0 0 1 1 0 1", //--> "___##_#":0 "###__#_":0 "0 0 1 1 0 0 1", "0 0 1 0 0 1 1", "0 1 1 1 1 0 1", "0 1 0 0 0 1 1", "0 1 1 0 0 0 1", "0 1 0 1 1 1 1", "0 1 1 1 0 1 1", "0 1 1 0 1 1 1", "0 0 0 1 0 1 1") //--> "___#_##":9 "###_#__":9 ).pump(Void,fcn([(n,bs)]){ bs-=" "; lhd[bs.translate("01","_#")]=n; rhd[bs.translate("10","_#")]=n; });   fcn parseBarCode(barcode, one=True){ // --> 12 digits upsideDown:='wrap{ // was I looking at this bar code upside down? if(one and (r:=parseBarCode(barcode.reverse(),False))) return(r); return(False); };   var [const] start=RegExp(String("_"*9, "+#_#")), tail="_"*7; if(not start.search(barcode)) return(upsideDown()); r,idx,d,mark := List(), start.matched[0][1], lhd, "_#_#_"; do(2){ do(6){ if(Void==(z:=d.find(barcode[idx,7]))) return(upsideDown()); r.append(z); idx+=7; } if(barcode[idx,5] != mark) return(Void); d,idx,mark = rhd, idx+5, "#_#__"; } if(tail!=barcode[idx,7]) return(Void); // 9 trailing blanks? two checked above r }
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
#Mathematica_.2F_Wolfram_Language
Mathematica / Wolfram Language
mystring = InputString["give me a string please"]; myinteger = Input["give me an integer please"];
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
#MATLAB
MATLAB
>> input('Input string: ') Input string: 'Hello'   ans =   Hello   >> input('Input number: ') Input number: 75000   ans =   75000   >> input('Input number, the number will be stored as a string: ','s') Input number, the number will be stored as a string: 75000   ans =   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
#Ruby
Ruby
require 'tk'   def main root = TkRoot.new l1 = TkLabel.new(root, "text" => "input a string") e1 = TkEntry.new(root) l2 = TkLabel.new(root, "text" => "input the number 75000") e2 = TkEntry.new(root) do validate "focusout" validatecommand lambda {e2.value.to_i == 75_000} invalidcommand lambda {focus_number_entry(e2)} end ok = TkButton.new(root) do text "OK" command lambda {validate_input(e1, e2)} end Tk.grid(l1, e1) Tk.grid(l2, e2) Tk.grid("x",ok, "sticky" => "w") Tk.mainloop end   def validate_input(text_entry, number_entry) if number_entry.value.to_i != 75_000 focus_number_entry(number_entry) else puts %Q{You entered: "#{text_entry.value}" and "#{number_entry.value}"} root.destroy end end   def focus_number_entry(widget) widget \ .configure("background" => "red", "foreground" => "white") \ .selection_range(0, "end") \ .focus end   main
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
#Ruby
Ruby
require 'cgi' puts CGI.escape("http://foo bar/").gsub("+", "%20") # => "http%3A%2F%2Ffoo%20bar%2F"
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
#Run_BASIC
Run BASIC
urlIn$ = "http://foo bar/"   for i = 1 to len(urlIn$) a$ = mid$(urlIn$,i,1) if (a$ >= "0" and a$ <= "9") _ or (a$ >= "A" and a$ <= "Z") _ or (a$ >= "a" and a$ <= "z") then url$ = url$ + a$ else url$ = url$ + "%"+dechex$(asc(a$)) next i print urlIn$;" -> ";url$
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
#Ol
Ol
  ; Declare the symbol 'var1' and associate number 123 with it. (define var1 123) (print var1) ; ==> 123   ; Reassociate number 321 with var1. (define var1 321) (print var1)   ; Create function that prints value of var1 ... (define (show) (print var1)) ; ... and eassociate number 42 with var1. (define var1 42)   (print var1) ; ==> 42 ; var1 prints as 42, but... (show) ; ==> 321 ; ... function 'show' still print old associated value  
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
#Openscad
Openscad
  mynumber=5+4; // This gives a value of nine  
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
#M2000_Interpreter
M2000 Interpreter
  Module checkit { class Vector { \\ by default are double a,b,c Property ToString$ { Value { link parent a,b,c to a,b,c value$=format$("({0}, {1}, {2})",a,b,c) } } Operator "==" { read n push .a==n.a and .b==n.b and .c==n.c } Operator Unary { .a-! : .b-! : .c-! } Operator "+" { Read v2 For this, v2 { .a+=..a :.b+=..b:.c+=..c: } } Function Mul(r) { vv=this for vv { .a*=r:.b*=r:.c*=r } =vv } Function Dot(v2) { def double sum for this, v2 { sum=.a*..a+.b*..b+.c*..c } =sum } Operator "*" { Read v2 For This, v2 { Push .b*..c-.c*..b Push .c*..a-.a*..c .c<=.a*..b-.b*..a Read .b, .a } } class: module Vector { if match("NNN") then { Read .a,.b,.c } } } A=Vector(3,4,5) B=Vector(4,3,5) C=Vector(-5,-12,-13) Print "A=";A.toString$ Print "B=";B.toString$ Print "C=";C.toString$ Print "A dot B="; A.dot(B) AxB=A*B Print "A x B="; AxB.toString$ Print "A dot (B x C)=";A.dot(B*C) AxBxC=A*(B*C) Print "A x (B x C)=";AxBxC.toString$ Def ToString$(a)=a.toString$ Print "A x (B x C)=";ToString$(A*(B*C)) } 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".
#R
R
URLdecode("http%3A%2F%2Ffoo%20bar%2F")