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'use strict';var ArgumentsError = require('../error/ArgumentsError');var deepMap = require('../utils/collection/deepMap');function factory (type, config, load, typed) { var AccessorNode = load(require('./node/AccessorNode')); var ArrayNode = load(require('./node/ArrayNode')); var AssignmentNode = load(require('./node/AssignmentNode')); var BlockNode = load(require('./node/BlockNode')); var ConditionalNode = load(require('./node/ConditionalNode')); var ConstantNode = load(require('./node/ConstantNode')); var FunctionAssignmentNode = load(require('./node/FunctionAssignmentNode')); var IndexNode = load(require('./node/IndexNode')); var ObjectNode = load(require('./node/ObjectNode')); var OperatorNode = load(require('./node/OperatorNode')); var ParenthesisNode = load(require('./node/ParenthesisNode')); var FunctionNode = load(require('./node/FunctionNode')); var RangeNode = load(require('./node/RangeNode')); var SymbolNode = load(require('./node/SymbolNode')); /** * Parse an expression. Returns a node tree, which can be evaluated by * invoking node.eval(); * * Syntax: * * parse(expr) * parse(expr, options) * parse([expr1, expr2, expr3, ...]) * parse([expr1, expr2, expr3, ...], options) * * Example: * * var node = parse('sqrt(3^2 + 4^2)'); * node.compile(math).eval(); // 5 * * var scope = {a:3, b:4} * var node = parse('a * b'); // 12 * var code = node.compile(math); * code.eval(scope); // 12 * scope.a = 5; * code.eval(scope); // 20 * * var nodes = math.parse(['a = 3', 'b = 4', 'a * b']); * nodes[2].compile(math).eval(); // 12 * * @param {string | string[] | Matrix} expr * @param {{nodes: Object<string, Node>}} [options] Available options: * - `nodes` a set of custom nodes * @return {Node | Node[]} node * @throws {Error} */ function parse (expr, options) { if (arguments.length != 1 && arguments.length != 2) { throw new ArgumentsError('parse', arguments.length, 1, 2); } // pass extra nodes extra_nodes = (options && options.nodes) ? options.nodes : {}; if (typeof expr === 'string') { // parse a single expression expression = expr; return parseStart(); } else if (Array.isArray(expr) || expr instanceof type.Matrix) { // parse an array or matrix with expressions return deepMap(expr, function (elem) { if (typeof elem !== 'string') throw new TypeError('String expected'); expression = elem; return parseStart(); }); } else { // oops throw new TypeError('String or matrix expected'); } } // token types enumeration var TOKENTYPE = { NULL : 0, DELIMITER : 1, NUMBER : 2, SYMBOL : 3, UNKNOWN : 4 }; // map with all delimiters var DELIMITERS = { ',': true, '(': true, ')': true, '[': true, ']': true, '{': true, '}': true, '\"': true, ';': true, '+': true, '-': true, '*': true, '.*': true, '/': true, './': true, '%': true, '^': true, '.^': true, '~': true, '!': true, '&': true, '|': true, '^|': true, '\'': true, '=': true, ':': true, '?': true, '==': true, '!=': true, '<': true, '>': true, '<=': true, '>=': true, '<<': true, '>>': true, '>>>': true }; // map with all named delimiters var NAMED_DELIMITERS = { 'mod': true, 'to': true, 'in': true, 'and': true, 'xor': true, 'or': true, 'not': true }; var extra_nodes = {}; // current extra nodes var expression = ''; // current expression var comment = ''; // last parsed comment var index = 0; // current index in expr var c = ''; // current token character in expr var token = ''; // current token var token_type = TOKENTYPE.NULL; // type of the token var nesting_level = 0; // level of nesting inside parameters, used to ignore newline characters var conditional_level = null; // when a conditional is being parsed, the level of the conditional is stored here /** * Get the first character from the expression. * The character is stored into the char c. If the end of the expression is * reached, the function puts an empty string in c. * @private */ function first() { index = 0; c = expression.charAt(0); nesting_level = 0; conditional_level = null; } /** * Get the next character from the expression. * The character is stored into the char c. If the end of the expression is * reached, the function puts an empty string in c. * @private */ function next() { index++; c = expression.charAt(index); } /** * Preview the previous character from the expression. * @return {string} cNext * @private */ function prevPreview() { return expression.charAt(index - 1); } /** * Preview the next character from the expression. * @return {string} cNext * @private */ function nextPreview() { return expression.charAt(index + 1); } /** * Preview the second next character from the expression. * @return {string} cNext * @private */ function nextNextPreview() { return expression.charAt(index + 2); } /** * Get next token in the current string expr. * The token and token type are available as token and token_type * @private */ function getToken() { token_type = TOKENTYPE.NULL; token = ''; comment = ''; // skip over whitespaces // space, tab, and newline when inside parameters while (parse.isWhitespace(c, nesting_level)) { next(); } // skip comment if (c == '#') { while (c != '\n' && c != '') { comment += c; next(); } } // check for end of expression if (c == '') { // token is still empty token_type = TOKENTYPE.DELIMITER; return; } // check for new line character if (c == '\n' && !nesting_level) { token_type = TOKENTYPE.DELIMITER; token = c; next(); return; } // check for delimiters consisting of 3 characters var c2 = c + nextPreview(); var c3 = c2 + nextNextPreview(); if (c3.length == 3 && DELIMITERS[c3]) { token_type = TOKENTYPE.DELIMITER; token = c3; next(); next(); next(); return; } // check for delimiters consisting of 2 characters if (c2.length == 2 && DELIMITERS[c2]) { token_type = TOKENTYPE.DELIMITER; token = c2; next(); next(); return; } // check for delimiters consisting of 1 character if (DELIMITERS[c]) { token_type = TOKENTYPE.DELIMITER; token = c; next(); return; } // check for a number if (parse.isDigitDot(c)) { token_type = TOKENTYPE.NUMBER; // get number, can have a single dot if (c == '.') { token += c; next(); if (!parse.isDigit(c)) { // this is no number, it is just a dot (can be dot notation) token_type = TOKENTYPE.DELIMITER; } } else { while (parse.isDigit(c)) { token += c; next(); } if (parse.isDecimalMark(c, nextPreview())) { token += c; next(); } } while (parse.isDigit(c)) { token += c; next(); } // check for exponential notation like "2.3e-4", "1.23e50" or "2e+4" c2 = nextPreview(); if (c == 'E' || c == 'e') { if (parse.isDigit(c2) || c2 == '-' || c2 == '+') { token += c; next(); if (c == '+' || c == '-') { token += c; next(); } // Scientific notation MUST be followed by an exponent if (!parse.isDigit(c)) { throw createSyntaxError('Digit expected, got "' + c + '"'); } while (parse.isDigit(c)) { token += c; next(); } if (parse.isDecimalMark(c, nextPreview())) { throw createSyntaxError('Digit expected, got "' + c + '"'); } } else if (c2 == '.') { next(); throw createSyntaxError('Digit expected, got "' + c + '"'); } } return; } // check for variables, functions, named operators if (parse.isAlpha(c, prevPreview(), nextPreview())) { while (parse.isAlpha(c, prevPreview(), nextPreview()) || parse.isDigit(c)) { token += c; next(); } if (NAMED_DELIMITERS.hasOwnProperty(token)) { token_type = TOKENTYPE.DELIMITER; } else { token_type = TOKENTYPE.SYMBOL; } return; } // something unknown is found, wrong characters -> a syntax error token_type = TOKENTYPE.UNKNOWN; while (c != '') { token += c; next(); } throw createSyntaxError('Syntax error in part "' + token + '"'); } /** * Get next token and skip newline tokens */ function getTokenSkipNewline () { do { getToken(); } while (token == '\n'); } /** * Open parameters. * New line characters will be ignored until closeParams() is called */ function openParams() { nesting_level++; } /** * Close parameters. * New line characters will no longer be ignored */ function closeParams() { nesting_level--; } /** * Checks whether the current character `c` is a valid alpha character: * * - A latin letter (upper or lower case) Ascii: a-z, A-Z * - An underscore Ascii: _ * - A dollar sign Ascii: $ * - A latin letter with accents Unicode: \u00C0 - \u02AF * - A greek letter Unicode: \u0370 - \u03FF * - A mathematical alphanumeric symbol Unicode: \u{1D400} - \u{1D7FF} excluding invalid code points * * The previous and next characters are needed to determine whether * this character is part of a unicode surrogate pair. * * @param {string} c Current character in the expression * @param {string} cPrev Previous character * @param {string} cNext Next character * @return {boolean} */ parse.isAlpha = function isAlpha (c, cPrev, cNext) { return parse.isValidLatinOrGreek(c) || parse.isValidMathSymbol(c, cNext) || parse.isValidMathSymbol(cPrev, c); }; /** * Test whether a character is a valid latin, greek, or letter-like character * @param {string} c * @return {boolean} */ parse.isValidLatinOrGreek = function isValidLatinOrGreek (c) { return /^[a-zA-Z_$\u00C0-\u02AF\u0370-\u03FF\u2100-\u214F]$/.test(c); }; /** * Test whether two given 16 bit characters form a surrogate pair of a * unicode math symbol. * * http://unicode-table.com/en/ * http://www.wikiwand.com/en/Mathematical_operators_and_symbols_in_Unicode * * Note: In ES6 will be unicode aware: * http://stackoverflow.com/questions/280712/javascript-unicode-regexes * https://mathiasbynens.be/notes/es6-unicode-regex * * @param {string} high * @param {string} low * @return {boolean} */ parse.isValidMathSymbol = function isValidMathSymbol (high, low) { return /^[\uD835]$/.test(high) && /^[\uDC00-\uDFFF]$/.test(low) && /^[^\uDC55\uDC9D\uDCA0\uDCA1\uDCA3\uDCA4\uDCA7\uDCA8\uDCAD\uDCBA\uDCBC\uDCC4\uDD06\uDD0B\uDD0C\uDD15\uDD1D\uDD3A\uDD3F\uDD45\uDD47-\uDD49\uDD51\uDEA6\uDEA7\uDFCC\uDFCD]$/.test(low); }; /** * Check whether given character c is a white space character: space, tab, or enter * @param {string} c * @param {number} nestingLevel * @return {boolean} */ parse.isWhitespace = function isWhitespace (c, nestingLevel) { // TODO: also take '\r' carriage return as newline? Or does that give problems on mac? return c == ' ' || c == '\t' || (c == '\n' && nestingLevel > 0); }; /** * Test whether the character c is a decimal mark (dot). * This is the case when it's not the start of a delimiter '.*', './', or '.^' * @param {string} c * @param {string} cNext * @return {boolean} */ parse.isDecimalMark = function isDecimalMark (c, cNext) { return c == '.' && cNext !== '/' && cNext !== '*' && cNext !== '^'; }; /** * checks if the given char c is a digit or dot * @param {string} c a string with one character * @return {boolean} */ parse.isDigitDot = function isDigitDot (c) { return ((c >= '0' && c <= '9') || c == '.'); }; /** * checks if the given char c is a digit * @param {string} c a string with one character * @return {boolean} */ parse.isDigit = function isDigit (c) { return (c >= '0' && c <= '9'); }; /** * Start of the parse levels below, in order of precedence * @return {Node} node * @private */ function parseStart () { // get the first character in expression first(); getToken(); var node = parseBlock(); // check for garbage at the end of the expression // an expression ends with a empty character '' and token_type DELIMITER if (token != '') { if (token_type == TOKENTYPE.DELIMITER) { // user entered a not existing operator like "//" // TODO: give hints for aliases, for example with "<>" give as hint " did you mean != ?" throw createError('Unexpected operator ' + token); } else { throw createSyntaxError('Unexpected part "' + token + '"'); } } return node; } /** * Parse a block with expressions. Expressions can be separated by a newline * character '\n', or by a semicolon ';'. In case of a semicolon, no output * of the preceding line is returned. * @return {Node} node * @private */ function parseBlock () { var node; var blocks = []; var visible; if (token != '' && token != '\n' && token != ';') { node = parseAssignment(); node.comment = comment; } // TODO: simplify this loop while (token == '\n' || token == ';') { if (blocks.length == 0 && node) { visible = (token != ';'); blocks.push({ node: node, visible: visible }); } getToken(); if (token != '\n' && token != ';' && token != '') { node = parseAssignment(); node.comment = comment; visible = (token != ';'); blocks.push({ node: node, visible: visible }); } } if (blocks.length > 0) { return new BlockNode(blocks); } else { if (!node) { node = new ConstantNode('undefined', 'undefined'); node.comment = comment; } return node } } /** * Assignment of a function or variable, * - can be a variable like 'a=2.3' * - or a updating an existing variable like 'matrix(2,3:5)=[6,7,8]' * - defining a function like 'f(x) = x^2' * @return {Node} node * @private */ function parseAssignment () { var name, args, value, valid; var node = parseConditional(); if (token == '=') { if (type.isSymbolNode(node)) { // parse a variable assignment like 'a = 2/3' name = node.name; getTokenSkipNewline(); value = parseAssignment(); return new AssignmentNode(new SymbolNode(name), value); } else if (type.isAccessorNode(node)) { // parse a matrix subset assignment like 'A[1,2] = 4' getTokenSkipNewline(); value = parseAssignment(); return new AssignmentNode(node.object, node.index, value); } // BUG: CWE-94 Improper Control of Generation of Code ('Code Injection') // else if (type.isFunctionNode(node)) { // FIXED: else if (type.isFunctionNode(node) && type.isSymbolNode(node.fn)) { // parse function assignment like 'f(x) = x^2' valid = true; args = []; name = node.name; node.args.forEach(function (arg, index) { if (type.isSymbolNode(arg)) { args[index] = arg.name; } else { valid = false; } }); if (valid) { getTokenSkipNewline(); value = parseAssignment(); return new FunctionAssignmentNode(name, args, value); } } throw createSyntaxError('Invalid left hand side of assignment operator ='); } return node; } /** * conditional operation * * condition ? truePart : falsePart * * Note: conditional operator is right-associative * * @return {Node} node * @private */ function parseConditional () { var node = parseLogicalOr(); while (token == '?') { // set a conditional level, the range operator will be ignored as long // as conditional_level == nesting_level. var prev = conditional_level; conditional_level = nesting_level; getTokenSkipNewline(); var condition = node; var trueExpr = parseAssignment(); if (token != ':') throw createSyntaxError('False part of conditional expression expected'); conditional_level = null; getTokenSkipNewline(); var falseExpr = parseAssignment(); // Note: check for conditional operator again, right associativity node = new ConditionalNode(condition, trueExpr, falseExpr); // restore the previous conditional level conditional_level = prev; } return node; } /** * logical or, 'x or y' * @return {Node} node * @private */ function parseLogicalOr() { var node = parseLogicalXor(); while (token == 'or') { getTokenSkipNewline(); node = new OperatorNode('or', 'or', [node, parseLogicalXor()]); } return node; } /** * logical exclusive or, 'x xor y' * @return {Node} node * @private */ function parseLogicalXor() { var node = parseLogicalAnd(); while (token == 'xor') { getTokenSkipNewline(); node = new OperatorNode('xor', 'xor', [node, parseLogicalAnd()]); } return node; } /** * logical and, 'x and y' * @return {Node} node * @private */ function parseLogicalAnd() { var node = parseBitwiseOr(); while (token == 'and') { getTokenSkipNewline(); node = new OperatorNode('and', 'and', [node, parseBitwiseOr()]); } return node; } /** * bitwise or, 'x | y' * @return {Node} node * @private */ function parseBitwiseOr() { var node = parseBitwiseXor(); while (token == '|') { getTokenSkipNewline(); node = new OperatorNode('|', 'bitOr', [node, parseBitwiseXor()]); } return node; } /** * bitwise exclusive or (xor), 'x ^| y' * @return {Node} node * @private */ function parseBitwiseXor() { var node = parseBitwiseAnd(); while (token == '^|') { getTokenSkipNewline(); node = new OperatorNode('^|', 'bitXor', [node, parseBitwiseAnd()]); } return node; } /** * bitwise and, 'x & y' * @return {Node} node * @private */ function parseBitwiseAnd () { var node = parseRelational(); while (token == '&') { getTokenSkipNewline(); node = new OperatorNode('&', 'bitAnd', [node, parseRelational()]); } return node; } /** * relational operators * @return {Node} node * @private */ function parseRelational () { var node, operators, name, fn, params; node = parseShift(); operators = { '==': 'equal', '!=': 'unequal', '<': 'smaller', '>': 'larger', '<=': 'smallerEq', '>=': 'largerEq' }; while (operators.hasOwnProperty(token)) { name = token; fn = operators[name]; getTokenSkipNewline(); params = [node, parseShift()]; node = new OperatorNode(name, fn, params); } return node; } /** * Bitwise left shift, bitwise right arithmetic shift, bitwise right logical shift * @return {Node} node * @private */ function parseShift () { var node, operators, name, fn, params; node = parseConversion(); operators = { '<<' : 'leftShift', '>>' : 'rightArithShift', '>>>' : 'rightLogShift' }; while (operators.hasOwnProperty(token)) { name = token; fn = operators[name]; getTokenSkipNewline(); params = [node, parseConversion()]; node = new OperatorNode(name, fn, params); } return node; } /** * conversion operators 'to' and 'in' * @return {Node} node * @private */ function parseConversion () { var node, operators, name, fn, params; node = parseRange(); operators = { 'to' : 'to', 'in' : 'to' // alias of 'to' }; while (operators.hasOwnProperty(token)) { name = token; fn = operators[name]; getTokenSkipNewline(); if (name === 'in' && token === '') { // end of expression -> this is the unit 'in' ('inch') node = new OperatorNode('*', 'multiply', [node, new SymbolNode('in')], true); } else { // operator 'a to b' or 'a in b' params = [node, parseRange()]; node = new OperatorNode(name, fn, params); } } return node; } /** * parse range, "start:end", "start:step:end", ":", "start:", ":end", etc * @return {Node} node * @private */ function parseRange () { var node, params = []; if (token == ':') { // implicit start=1 (one-based) node = new ConstantNode('1', 'number'); } else { // explicit start node = parseAddSubtract(); } if (token == ':' && (conditional_level !== nesting_level)) { // we ignore the range operator when a conditional operator is being processed on the same level params.push(node); // parse step and end while (token == ':' && params.length < 3) { getTokenSkipNewline(); if (token == ')' || token == ']' || token == ',' || token == '') { // implicit end params.push(new SymbolNode('end')); } else { // explicit end params.push(parseAddSubtract()); } } if (params.length == 3) { // params = [start, step, end] node = new RangeNode(params[0], params[2], params[1]); // start, end, step } else { // length == 2 // params = [start, end] node = new RangeNode(params[0], params[1]); // start, end } } return node; } /** * add or subtract * @return {Node} node * @private */ function parseAddSubtract () { var node, operators, name, fn, params; node = parseMultiplyDivide(); operators = { '+': 'add', '-': 'subtract' }; while (operators.hasOwnProperty(token)) { name = token; fn = operators[name]; getTokenSkipNewline(); params = [node, parseMultiplyDivide()]; node = new OperatorNode(name, fn, params); } return node; } /** * multiply, divide, modulus * @return {Node} node * @private */ function parseMultiplyDivide () { var node, last, operators, name, fn; node = parseUnary(); last = node; operators = { '*': 'multiply', '.*': 'dotMultiply', '/': 'divide', './': 'dotDivide', '%': 'mod', 'mod': 'mod' }; while (true) { if (operators.hasOwnProperty(token)) { // explicit operators name = token; fn = operators[name]; getTokenSkipNewline(); last = parseUnary(); node = new OperatorNode(name, fn, [node, last]); } else if ((token_type === TOKENTYPE.SYMBOL) || (token === 'in' && type.isConstantNode(node)) || (token_type === TOKENTYPE.NUMBER && !type.isConstantNode(last) && (!type.isOperatorNode(last) || last.op === '!')) || (token === '(')) { // parse implicit multiplication // // symbol: implicit multiplication like '2a', '(2+3)a', 'a b' // number: implicit multiplication like '(2+3)2' // parenthesis: implicit multiplication like '2(3+4)', '(3+4)(1+2)' last = parseUnary(); node = new OperatorNode('*', 'multiply', [node, last], true /*implicit*/); } else { break; } } return node; } /** * Unary plus and minus, and logical and bitwise not * @return {Node} node * @private */ function parseUnary () { var name, params, fn; var operators = { '-': 'unaryMinus', '+': 'unaryPlus', '~': 'bitNot', 'not': 'not' }; if (operators.hasOwnProperty(token)) { fn = operators[token]; name = token; getTokenSkipNewline(); params = [parseUnary()]; return new OperatorNode(name, fn, params); } return parsePow(); } /** * power * Note: power operator is right associative * @return {Node} node * @private */ function parsePow () { var node, name, fn, params; node = parseLeftHandOperators(); if (token == '^' || token == '.^') { name = token; fn = (name == '^') ? 'pow' : 'dotPow'; getTokenSkipNewline(); params = [node, parseUnary()]; // Go back to unary, we can have '2^-3' node = new OperatorNode(name, fn, params); } return node; } /** * Left hand operators: factorial x!, transpose x' * @return {Node} node * @private */ function parseLeftHandOperators () { var node, operators, name, fn, params; node = parseCustomNodes(); operators = { '!': 'factorial', '\'': 'transpose' }; while (operators.hasOwnProperty(token)) { name = token; fn = operators[name]; getToken(); params = [node]; node = new OperatorNode(name, fn, params); node = parseAccessors(node); } return node; } /** * Parse a custom node handler. A node handler can be used to process * nodes in a custom way, for example for handling a plot. * * A handler must be passed as second argument of the parse function. * - must extend math.expression.node.Node * - must contain a function _compile(defs: Object) : string * - must contain a function find(filter: Object) : Node[] * - must contain a function toString() : string * - the constructor is called with a single argument containing all parameters * * For example: * * nodes = { * 'plot': PlotHandler * }; * * The constructor of the handler is called as: * * node = new PlotHandler(params); * * The handler will be invoked when evaluating an expression like: * * node = math.parse('plot(sin(x), x)', nodes); * * @return {Node} node * @private */ function parseCustomNodes () { var params = []; if (token_type == TOKENTYPE.SYMBOL && extra_nodes.hasOwnProperty(token)) { var CustomNode = extra_nodes[token]; getToken(); // parse parameters if (token == '(') { params = []; openParams(); getToken(); if (token != ')') { params.push(parseAssignment()); // parse a list with parameters while (token == ',') { getToken(); params.push(parseAssignment()); } } if (token != ')') { throw createSyntaxError('Parenthesis ) expected'); } closeParams(); getToken(); } // create a new custom node //noinspection JSValidateTypes return new CustomNode(params); } return parseSymbol(); } /** * parse symbols: functions, variables, constants, units * @return {Node} node * @private */ function parseSymbol () { var node, name; if (token_type == TOKENTYPE.SYMBOL || (token_type == TOKENTYPE.DELIMITER && token in NAMED_DELIMITERS)) { name = token; getToken(); // parse function parameters and matrix index node = new SymbolNode(name); node = parseAccessors(node); return node; } return parseString(); } /** * parse accessors: * - function invocation in round brackets (...), for example sqrt(2) * - index enclosed in square brackets [...], for example A[2,3] * - dot notation for properties, like foo.bar * @param {Node} node Node on which to apply the parameters. If there * are no parameters in the expression, the node * itself is returned * @param {string[]} [types] Filter the types of notations * can be ['(', '[', '.'] * @return {Node} node * @private */ function parseAccessors (node, types) { var params; while ((token === '(' || token === '[' || token === '.') && (!types || types.indexOf(token) !== -1)) { params = []; if (token === '(') { if (type.isSymbolNode(node) || type.isAccessorNode(node) || type.isFunctionNode(node)) { // function invocation like fn(2, 3) openParams(); getToken(); if (token !== ')') { params.push(parseAssignment()); // parse a list with parameters while (token === ',') { getToken(); params.push(parseAssignment()); } } if (token !== ')') { throw createSyntaxError('Parenthesis ) expected'); } closeParams(); getToken(); node = new FunctionNode(node, params); } else { // implicit multiplication like (2+3)(4+5) // don't parse it here but let it be handled by parseMultiplyDivide // with correct precedence return node; } } else if (token === '[') { // index notation like variable[2, 3] openParams(); getToken(); if (token !== ']') { params.push(parseAssignment()); // parse a list with parameters while (token === ',') { getToken(); params.push(parseAssignment()); } } if (token !== ']') { throw createSyntaxError('Parenthesis ] expected'); } closeParams(); getToken(); node = new AccessorNode(node, new IndexNode(params)); } else { // dot notation like variable.prop getToken(); if (token_type !== TOKENTYPE.SYMBOL) { throw createSyntaxError('Property name expected after dot'); } params.push(new ConstantNode(token)); getToken(); var dotNotation = true; node = new AccessorNode(node, new IndexNode(params, dotNotation)); } } return node; } /** * parse a string. * A string is enclosed by double quotes * @return {Node} node * @private */ function parseString () { var node, str; if (token == '"') { str = parseStringToken(); // create constant node = new ConstantNode(str, 'string'); // parse index parameters node = parseAccessors(node); return node; } return parseMatrix(); } /** * Parse a string surrounded by double quotes "..." * @return {string} */ function parseStringToken () { var str = ''; while (c != '' && c != '\"') { if (c == '\\') { // escape character str += c; next(); } str += c; next(); } getToken(); if (token != '"') { throw createSyntaxError('End of string " expected'); } getToken(); return str; } /** * parse the matrix * @return {Node} node * @private */ function parseMatrix () { var array, params, rows, cols; if (token == '[') { // matrix [...] openParams(); getToken(); if (token != ']') { // this is a non-empty matrix var row = parseRow(); if (token == ';') { // 2 dimensional array rows = 1; params = [row]; // the rows of the matrix are separated by dot-comma's while (token == ';') { getToken(); params[rows] = parseRow(); rows++; } if (token != ']') { throw createSyntaxError('End of matrix ] expected'); } closeParams(); getToken(); // check if the number of columns matches in all rows cols = params[0].items.length; for (var r = 1; r < rows; r++) { if (params[r].items.length != cols) { throw createError('Column dimensions mismatch ' + '(' + params[r].items.length + ' != ' + cols + ')'); } } array = new ArrayNode(params); } else { // 1 dimensional vector if (token != ']') { throw createSyntaxError('End of matrix ] expected'); } closeParams(); getToken(); array = row; } } else { // this is an empty matrix "[ ]" closeParams(); getToken(); array = new ArrayNode([]); } return parseAccessors(array); } return parseObject(); } /** * Parse a single comma-separated row from a matrix, like 'a, b, c' * @return {ArrayNode} node */ function parseRow () { var params = [parseAssignment()]; var len = 1; while (token == ',') { getToken(); // parse expression params[len] = parseAssignment(); len++; } return new ArrayNode(params); } /** * parse an object, enclosed in angle brackets{...}, for example {value: 2} * @return {Node} node * @private */ function parseObject () { if (token == '{') { var key; var properties = {}; do { getToken(); if (token != '}') { // parse key if (token == '"') { key = parseStringToken(); } else if (token_type == TOKENTYPE.SYMBOL) { key = token; getToken(); } else { throw createSyntaxError('Symbol or string expected as object key'); } // parse key/value separator if (token != ':') { throw createSyntaxError('Colon : expected after object key'); } getToken(); // parse key properties[key] = parseAssignment(); } } while (token == ','); if (token != '}') { throw createSyntaxError('Comma , or bracket } expected after object value'); } getToken(); var node = new ObjectNode(properties); // parse index parameters node = parseAccessors(node); return node; } return parseNumber(); } /** * parse a number * @return {Node} node * @private */ function parseNumber () { var number; if (token_type == TOKENTYPE.NUMBER) { // this is a number number = token; getToken(); return new ConstantNode(number, 'number'); } return parseParentheses(); } /** * parentheses * @return {Node} node * @private */ function parseParentheses () { var node; // check if it is a parenthesized expression if (token == '(') { // parentheses (...) openParams(); getToken(); node = parseAssignment(); // start again if (token != ')') { throw createSyntaxError('Parenthesis ) expected'); } closeParams(); getToken(); node = new ParenthesisNode(node); node = parseAccessors(node); return node; } return parseEnd(); } /** * Evaluated when the expression is not yet ended but expected to end * @return {Node} res * @private */ function parseEnd () { if (token == '') { // syntax error or unexpected end of expression throw createSyntaxError('Unexpected end of expression'); } else if (token === "'") { throw createSyntaxError('Value expected. Note: strings must be enclosed by double quotes'); } else { throw createSyntaxError('Value expected'); } } /** * Shortcut for getting the current row value (one based) * Returns the line of the currently handled expression * @private */ /* TODO: implement keeping track on the row number function row () { return null; } */ /** * Shortcut for getting the current col value (one based) * Returns the column (position) where the last token starts * @private */ function col () { return index - token.length + 1; } /** * Create an error * @param {string} message * @return {SyntaxError} instantiated error * @private */ function createSyntaxError (message) { var c = col(); var error = new SyntaxError(message + ' (char ' + c + ')'); error['char'] = c; return error; } /** * Create an error * @param {string} message * @return {Error} instantiated error * @private */ function createError (message) { var c = col(); var error = new SyntaxError(message + ' (char ' + c + ')'); error['char'] = c; return error; } return parse;}exports.name = 'parse';exports.path = 'expression';exports.factory = factory; |