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1090 lines
35 KiB
JavaScript
1090 lines
35 KiB
JavaScript
/* PEG.js compiler. */
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(function(undefined) {
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/* ===== PEG ===== */
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/* no var */ PEG = {};
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/*
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* Generates a parser from a specified grammar and returns it.
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*
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* The grammar must be a string in the format described by the metagramar in the
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* metagrammar.pegjs file.
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*
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* Throws |PEG.parser.SyntaxError| if the grammar contains a syntax error or
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* |PEG.GrammarError| if it contains a semantic error. Note that not all errors
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* are detected during the generation and some may protrude to the generated
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* parser and cause its malfunction.
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*/
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PEG.buildParser = function(grammar) {
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return PEG.compiler.compile(PEG.parser.parse(grammar));
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};
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/* ===== PEG.GrammarError ===== */
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/* Thrown when the grammar contains an error. */
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PEG.GrammarError = function(message) {
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this.name = "PEG.GrammarError";
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this.message = message;
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};
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PEG.GrammarError.prototype = Error.prototype;
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/* ===== PEG.ArrayUtils ===== */
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/* Array manipulation utility functions. */
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PEG.ArrayUtils = {
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/*
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* The code needs to be in sync with the code template in the compilation
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* function for "action" nodes.
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*/
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contains: function(array, value) {
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/*
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* Stupid IE does not have Array.prototype.indexOf, otherwise this function
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* would be a one-liner.
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*/
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var length = array.length;
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for (var i = 0; i < length; i++) {
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if (array[i] === value) {
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return true;
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}
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}
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return false;
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},
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each: function(array, callback) {
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var length = array.length;
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for (var i = 0; i < length; i++) {
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callback(array[i]);
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}
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},
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map: function(array, callback) {
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var result = [];
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var length = array.length;
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for (var i = 0; i < length; i++) {
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result[i] = callback(array[i]);
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}
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return result;
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}
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};
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/* ===== PEG.StringUtils ===== */
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/* String manipulation utility functions. */
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PEG.StringUtils = {
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/*
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* Surrounds the string with quotes and escapes characters inside so that the
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* result is a valid JavaScript string.
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*
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* The code needs to be in sync with th code template in the compilation
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* function for "action" nodes.
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*/
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quote: function(s) {
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/*
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* ECMA-262, 5th ed., 7.8.4: All characters may appear literally in a string
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* literal except for the closing quote character, backslash, carriage
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* return, line separator, paragraph separator, and line feed. Any character
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* may appear in the form of an escape sequence.
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*/
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return '"' + s
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.replace(/\\/g, '\\\\') // backslash
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.replace(/"/g, '\\"') // closing quote character
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.replace(/\r/g, '\\r') // carriage return
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.replace(/\u2028/g, '\\u2028') // line separator
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.replace(/\u2029/g, '\\u2029') // paragraph separator
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.replace(/\n/g, '\\n') // line feed
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+ '"';
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}
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};
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/* ===== PEG.RegExpUtils ===== */
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/* RegExp manipulation utility functions. */
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PEG.RegExpUtils = {
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/*
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* Escapes characters inside the string so that it can be used as a list of
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* characters in a character class of a regular expression.
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*/
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quoteForClass: function(s) {
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/* Based on ECMA-262, 5th ed., 7.8.5 & 15.10.1. */
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return s
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.replace(/\\/g, '\\\\') // backslash
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.replace(/\0/g, '\\0') // null, IE needs this
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.replace(/\//g, '\\/') // closing slash
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.replace(/]/g, '\\]') // closing bracket
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.replace(/-/g, '\\-') // dash
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.replace(/\r/g, '\\r') // carriage return
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.replace(/\u2028/g, '\\u2028') // line separator
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.replace(/\u2029/g, '\\u2029') // paragraph separator
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.replace(/\n/g, '\\n') // line feed
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}
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};
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/* ===== PEG.compiler ===== */
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PEG.compiler = {
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/*
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* Generates a parser from a specified grammar AST. Throws |PEG.GrammarError|
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* if the AST contains a semantic error. Note that not all errors are detected
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* during the generation and some may protrude to the generated parser and
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* cause its malfunction.
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*/
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compile: function(ast) {
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for (var i = 0; i < this.checks.length; i++) {
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this.checks[i](ast);
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}
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for (var i = 0; i < this.passes.length; i++) {
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ast = this.passes[i](ast);
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}
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var source = this.emitter(ast);
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var result = eval(source);
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result._source = source;
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return result;
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}
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};
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/*
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* Checks made on the grammar AST before compilation. Each check is a function
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* that is passed the AST and does not return anything. If the check passes, the
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* function does not do anything special, otherwise it throws
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* |PEG.GrammarError|. The checks are run in sequence in order of their
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* definition.
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*/
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PEG.compiler.checks = [
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/* Checks that all referenced rules exist. */
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function(ast) {
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function nop() {}
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function checkExpression(node) { check(node.expression); }
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function checkSubnodes(propertyName) {
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return function(node) {
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PEG.ArrayUtils.each(node[propertyName], check);
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};
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}
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var checkFunctions = {
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grammar:
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function(node) {
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for (var name in node.rules) {
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check(node.rules[name]);
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}
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},
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rule: checkExpression,
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choice: checkSubnodes("alternatives"),
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sequence: checkSubnodes("elements"),
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labeled: checkExpression,
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simple_and: checkExpression,
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simple_not: checkExpression,
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semantic_and: nop,
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semantic_not: nop,
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optional: checkExpression,
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zero_or_more: checkExpression,
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one_or_more: checkExpression,
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action: checkExpression,
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rule_ref:
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function(node) {
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if (ast.rules[node.name] === undefined) {
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throw new PEG.GrammarError(
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"Referenced rule \"" + node.name + "\" does not exist."
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);
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}
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},
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literal: nop,
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any: nop,
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"class": nop
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};
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function check(node) { checkFunctions[node.type](node); }
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check(ast);
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},
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/* Checks that no left recursion is present. */
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function(ast) {
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function nop() {}
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function checkExpression(node, appliedRules) {
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check(node.expression, appliedRules);
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}
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var checkFunctions = {
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grammar:
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function(node, appliedRules) {
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for (var name in node.rules) {
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check(ast.rules[name], appliedRules);
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}
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},
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rule:
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function(node, appliedRules) {
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check(node.expression, appliedRules.concat(node.name));
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},
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choice:
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function(node, appliedRules) {
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PEG.ArrayUtils.each(node.alternatives, function(alternative) {
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check(alternative, appliedRules);
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});
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},
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sequence:
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function(node, appliedRules) {
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if (node.elements.length > 0) {
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check(node.elements[0], appliedRules);
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}
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},
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labeled: checkExpression,
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simple_and: checkExpression,
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simple_not: checkExpression,
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semantic_and: nop,
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semantic_not: nop,
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optional: checkExpression,
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zero_or_more: checkExpression,
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one_or_more: checkExpression,
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action: checkExpression,
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rule_ref:
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function(node, appliedRules) {
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if (PEG.ArrayUtils.contains(appliedRules, node.name)) {
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throw new PEG.GrammarError(
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"Left recursion detected for rule \"" + node.name + "\"."
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);
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}
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check(ast.rules[node.name], appliedRules);
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},
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literal: nop,
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any: nop,
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"class": nop
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};
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function check(node, appliedRules) {
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checkFunctions[node.type](node, appliedRules);
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}
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check(ast, []);
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}
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];
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/*
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* Optimalization passes made on the grammar AST before compilation. Each pass
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* is a function that is passed the AST and returns a new AST. The AST can be
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* modified in-place by the pass. The passes are run in sequence in order of
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* their definition.
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*/
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PEG.compiler.passes = [
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/*
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* Removes proxy rules -- that is, rules that only delegate to other rule.
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*/
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function(ast) {
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function isProxyRule(node) {
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return node.type === "rule" && node.expression.type === "rule_ref";
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}
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function replaceRuleRefs(ast, from, to) {
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function nop() {}
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function replaceInExpression(node, from, to) {
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replace(node.expression, from, to);
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}
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function replaceInSubnodes(propertyName) {
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return function(node, from, to) {
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PEG.ArrayUtils.each(node[propertyName], function(node) {
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replace(node, from, to);
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});
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};
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}
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var replaceFunctions = {
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grammar:
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function(node, from, to) {
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for (var name in node.rules) {
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replace(ast.rules[name], from, to);
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}
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},
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rule: replaceInExpression,
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choice: replaceInSubnodes("alternatives"),
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sequence: replaceInSubnodes("elements"),
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labeled: replaceInExpression,
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simple_and: replaceInExpression,
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simple_not: replaceInExpression,
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semantic_and: nop,
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semantic_not: nop,
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optional: replaceInExpression,
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zero_or_more: replaceInExpression,
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one_or_more: replaceInExpression,
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action: replaceInExpression,
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rule_ref:
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function(node, from, to) {
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if (node.name === from) {
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node.name = to;
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}
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},
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literal: nop,
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any: nop,
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"class": nop
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};
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function replace(node, from, to) {
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replaceFunctions[node.type](node, from, to);
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}
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replace(ast, from, to);
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}
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for (var name in ast.rules) {
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if (isProxyRule(ast.rules[name])) {
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replaceRuleRefs(ast, ast.rules[name].name, ast.rules[name].expression.name);
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if (name === ast.startRule) {
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ast.startRule = ast.rules[name].expression.name;
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}
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delete ast.rules[name];
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}
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}
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return ast;
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}
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];
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/* Emits the generated code for the AST. */
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PEG.compiler.emitter = function(ast) {
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/*
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* Takes parts of code, interpolates variables inside them and joins them with
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* a newline.
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*
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* Variables are delimited with "${" and "}" and their names must be valid
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* identifiers (i.e. they must match [a-zA-Z_][a-zA-Z0-9_]*). Variable values
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* are specified as properties of the last parameter (if this is an object,
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* otherwise empty variable set is assumed). Undefined variables result in
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* throwing |Error|.
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*
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* There can be a filter specified after the variable name, prefixed with "|".
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* The filter name must be a valid identifier. The only recognized filter
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* right now is "string", which quotes the variable value as a JavaScript
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* string. Unrecognized filters result in throwing |Error|.
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*
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* If any part has multiple lines and the first line is indented by some
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* amount of whitespace (as defined by the /\s+/ JavaScript regular
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* expression), second to last lines are indented by the same amount of
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* whitespace. This results in nicely indented multiline code in variables
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* without making the templates look ugly.
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*
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* Examples:
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*
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* formatCode("foo", "bar"); // "foo\nbar"
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* formatCode("foo", "${bar}", { bar: "baz" }); // "foo\nbaz"
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* formatCode("foo", "${bar}"); // throws Error
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* formatCode("foo", "${bar|string}", { bar: "baz" }); // "foo\n\"baz\""
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* formatCode("foo", "${bar|eeek}", { bar: "baz" }); // throws Error
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* formatCode("foo", "${bar}", { bar: " baz\nqux" }); // "foo\n baz\n qux"
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*/
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function formatCode() {
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function interpolateVariablesInParts(parts) {
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return PEG.ArrayUtils.map(parts, function(part) {
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return part.replace(
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/\$\{([a-zA-Z_][a-zA-Z0-9_]*)(\|([a-zA-Z_][a-zA-Z0-9_]*))?\}/g,
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function(match, name, dummy, filter) {
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var value = vars[name];
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if (value === undefined) {
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throw new Error("Undefined variable: \"" + name + "\".");
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}
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if (filter !== undefined && filter != "") { // JavaScript engines differ here.
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if (filter === "string") {
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return PEG.StringUtils.quote(value);
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} else {
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throw new Error("Unrecognized filter: \"" + filter + "\".");
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}
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} else {
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return value;
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}
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}
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);
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});
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}
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function indentMultilineParts(parts) {
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return PEG.ArrayUtils.map(parts, function(part) {
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if (!/\n/.test(part)) { return part; }
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var firstLineWhitespacePrefix = part.match(/^\s*/)[0];
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var lines = part.split("\n");
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var linesIndented = [lines[0]].concat(
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PEG.ArrayUtils.map(lines.slice(1), function(line) {
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return firstLineWhitespacePrefix + line;
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})
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);
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return linesIndented.join("\n");
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});
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}
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var args = Array.prototype.slice.call(arguments);
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var vars = args[args.length - 1] instanceof Object ? args.pop() : {};
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return indentMultilineParts(interpolateVariablesInParts(args)).join("\n");
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};
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/* Unique ID generator. */
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var UID = {
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_counters: {},
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next: function(prefix) {
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this._counters[prefix] = this._counters[prefix] || 0;
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return prefix + this._counters[prefix]++;
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},
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reset: function() {
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this._counters = {};
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}
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};
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var emitFunctions = {
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grammar: function(node) {
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var initializerCode = node.initializer !== null
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? emit(node.initializer)
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: "";
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var parseFunctionDefinitions = [];
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for (var name in node.rules) {
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parseFunctionDefinitions.push(emit(node.rules[name]));
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}
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return formatCode(
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"(function(){",
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" /* Generated by PEG.js (http://pegjs.majda.cz/). */",
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" ",
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" var result = {",
|
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" /*",
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" * Parses the input with a generated parser. If the parsing is successfull,",
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" * returns a value explicitly or implicitly specified by the grammar from",
|
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" * which the parser was generated (see |PEG.buildParser|). If the parsing is",
|
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" * unsuccessful, throws |PEG.parser.SyntaxError| describing the error.",
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" */",
|
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" parse: function(input) {",
|
|
" var pos = 0;",
|
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" var rightmostMatchFailuresPos = 0;",
|
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" var rightmostMatchFailuresExpected = [];",
|
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" var cache = {};",
|
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" ",
|
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/* This needs to be in sync with PEG.StringUtils.quote. */
|
|
" function quoteString(s) {",
|
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" /*",
|
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" * ECMA-262, 5th ed., 7.8.4: All characters may appear literally in a",
|
|
" * string literal except for the closing quote character, backslash,",
|
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" * carriage return, line separator, paragraph separator, and line feed.",
|
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" * Any character may appear in the form of an escape sequence.",
|
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" */",
|
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" return '\"' + s",
|
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" .replace(/\\\\/g, '\\\\\\\\') // backslash",
|
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" .replace(/\"/g, '\\\\\"') // closing quote character",
|
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" .replace(/\\r/g, '\\\\r') // carriage return",
|
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" .replace(/\\u2028/g, '\\\\u2028') // line separator",
|
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" .replace(/\\u2029/g, '\\\\u2029') // paragraph separator",
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" .replace(/\\n/g, '\\\\n') // line feed",
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" + '\"';",
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" }",
|
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" ",
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/* This needs to be in sync with PEG.ArrayUtils.contains. */
|
|
" function arrayContains(array, value) {",
|
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" /*",
|
|
" * Stupid IE does not have Array.prototype.indexOf, otherwise this",
|
|
" * function would be a one-liner.",
|
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" */",
|
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" var length = array.length;",
|
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" for (var i = 0; i < length; i++) {",
|
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" if (array[i] === value) {",
|
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" return true;",
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" }",
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" }",
|
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" return false;",
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" }",
|
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" ",
|
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" function matchFailed(failure) {",
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" if (pos < rightmostMatchFailuresPos) {",
|
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" return;",
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" }",
|
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" ",
|
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" if (pos > rightmostMatchFailuresPos) {",
|
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" rightmostMatchFailuresPos = pos;",
|
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" rightmostMatchFailuresExpected = [];",
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" }",
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" ",
|
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" if (!arrayContains(rightmostMatchFailuresExpected, failure)) {",
|
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" rightmostMatchFailuresExpected.push(failure);",
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" }",
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" }",
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" ",
|
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" ${parseFunctionDefinitions}",
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" ",
|
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" function buildErrorMessage() {",
|
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" function buildExpected(failuresExpected) {",
|
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" switch (failuresExpected.length) {",
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" case 0:",
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" return 'end of input';",
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" case 1:",
|
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" return failuresExpected[0];",
|
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" default:",
|
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" failuresExpected.sort();",
|
|
" return failuresExpected.slice(0, failuresExpected.length - 1).join(', ')",
|
|
" + ' or '",
|
|
" + failuresExpected[failuresExpected.length - 1];",
|
|
" }",
|
|
" }",
|
|
" ",
|
|
" var expected = buildExpected(rightmostMatchFailuresExpected);",
|
|
" var actualPos = Math.max(pos, rightmostMatchFailuresPos);",
|
|
" var actual = actualPos < input.length",
|
|
" ? quoteString(input.charAt(actualPos))",
|
|
" : 'end of input';",
|
|
" ",
|
|
" return 'Expected ' + expected + ' but ' + actual + ' found.';",
|
|
" }",
|
|
" ",
|
|
" function computeErrorPosition() {",
|
|
" /*",
|
|
" * The first idea was to use |String.split| to break the input up to the",
|
|
" * error position along newlines and derive the line and column from",
|
|
" * there. However IE's |split| implementation is so broken that it was",
|
|
" * enough to prevent it.",
|
|
" */",
|
|
" ",
|
|
" var line = 1;",
|
|
" var column = 1;",
|
|
" var seenCR = false;",
|
|
" ",
|
|
" for (var i = 0; i < rightmostMatchFailuresPos; i++) {",
|
|
" var ch = input.charAt(i);",
|
|
" if (ch === '\\n') {",
|
|
" if (!seenCR) { line++; }",
|
|
" column = 1;",
|
|
" seenCR = false;",
|
|
" } else if (ch === '\\r' | ch === '\\u2028' || ch === '\\u2029') {",
|
|
" line++;",
|
|
" column = 1;",
|
|
" seenCR = true;",
|
|
" } else {",
|
|
" column++;",
|
|
" seenCR = false;",
|
|
" }",
|
|
" }",
|
|
" ",
|
|
" return { line: line, column: column };",
|
|
" }",
|
|
" ",
|
|
" ${initializerCode}",
|
|
" ",
|
|
" var result = parse_${startRule}({ reportMatchFailures: true });",
|
|
" ",
|
|
" /*",
|
|
" * The parser is now in one of the following three states:",
|
|
" *",
|
|
" * 1. The parser successfully parsed the whole input.",
|
|
" *",
|
|
" * - |result !== null|",
|
|
" * - |pos === input.length|",
|
|
" * - |rightmostMatchFailuresExpected| may or may not contain something",
|
|
" *",
|
|
" * 2. The parser successfully parsed only a part of the input.",
|
|
" *",
|
|
" * - |result !== null|",
|
|
" * - |pos < input.length|",
|
|
" * - |rightmostMatchFailuresExpected| may or may not contain something",
|
|
" *",
|
|
" * 3. The parser did not successfully parse any part of the input.",
|
|
" *",
|
|
" * - |result === null|",
|
|
" * - |pos === 0|",
|
|
" * - |rightmostMatchFailuresExpected| contains at least one failure",
|
|
" *",
|
|
" * All code following this comment (including called functions) must",
|
|
" * handle these states.",
|
|
" */",
|
|
" if (result === null || pos !== input.length) {",
|
|
" var errorPosition = computeErrorPosition();",
|
|
" throw new this.SyntaxError(",
|
|
" buildErrorMessage(),",
|
|
" errorPosition.line,",
|
|
" errorPosition.column",
|
|
" );",
|
|
" }",
|
|
" ",
|
|
" return result;",
|
|
" },",
|
|
" ",
|
|
" /* Returns the parser source code. */",
|
|
" toSource: function() { return this._source; }",
|
|
" };",
|
|
" ",
|
|
" /* Thrown when a parser encounters a syntax error. */",
|
|
" ",
|
|
" result.SyntaxError = function(message, line, column) {",
|
|
" this.name = 'SyntaxError';",
|
|
" this.message = message;",
|
|
" this.line = line;",
|
|
" this.column = column;",
|
|
" };",
|
|
" ",
|
|
" result.SyntaxError.prototype = Error.prototype;",
|
|
" ",
|
|
" return result;",
|
|
"})()",
|
|
{
|
|
initializerCode: initializerCode,
|
|
parseFunctionDefinitions: parseFunctionDefinitions.join("\n\n"),
|
|
startRule: node.startRule
|
|
}
|
|
);
|
|
},
|
|
|
|
initializer: function(node) {
|
|
return node.code;
|
|
},
|
|
|
|
rule: function(node) {
|
|
/*
|
|
* We want to reset variable names at the beginning of every function so
|
|
* that a little change in the source grammar does not change variables in
|
|
* all the generated code. This is desired especially when one has the
|
|
* generated grammar stored in a VCS (this is true e.g. for our
|
|
* metagrammar).
|
|
*/
|
|
UID.reset();
|
|
|
|
var resultVar = UID.next("result");
|
|
|
|
if (node.displayName !== null) {
|
|
var setReportMatchFailuresCode = formatCode(
|
|
"var savedReportMatchFailures = context.reportMatchFailures;",
|
|
"context.reportMatchFailures = false;"
|
|
);
|
|
var restoreReportMatchFailuresCode = formatCode(
|
|
"context.reportMatchFailures = savedReportMatchFailures;"
|
|
);
|
|
var reportMatchFailureCode = formatCode(
|
|
"if (context.reportMatchFailures && ${resultVar} === null) {",
|
|
" matchFailed(${displayName|string});",
|
|
"}",
|
|
{
|
|
displayName: node.displayName,
|
|
resultVar: resultVar
|
|
}
|
|
);
|
|
} else {
|
|
var setReportMatchFailuresCode = "";
|
|
var restoreReportMatchFailuresCode = "";
|
|
var reportMatchFailureCode = "";
|
|
}
|
|
|
|
return formatCode(
|
|
"function parse_${name}(context) {",
|
|
" var cacheKey = ${name|string} + '@' + pos;",
|
|
" var cachedResult = cache[cacheKey];",
|
|
" if (cachedResult) {",
|
|
" pos = cachedResult.nextPos;",
|
|
" return cachedResult.result;",
|
|
" }",
|
|
" ",
|
|
" ${setReportMatchFailuresCode}",
|
|
" ${code}",
|
|
" ${restoreReportMatchFailuresCode}",
|
|
" ${reportMatchFailureCode}",
|
|
" ",
|
|
" cache[cacheKey] = {",
|
|
" nextPos: pos,",
|
|
" result: ${resultVar}",
|
|
" };",
|
|
" return ${resultVar};",
|
|
"}",
|
|
{
|
|
name: node.name,
|
|
setReportMatchFailuresCode: setReportMatchFailuresCode,
|
|
restoreReportMatchFailuresCode: restoreReportMatchFailuresCode,
|
|
reportMatchFailureCode: reportMatchFailureCode,
|
|
code: emit(node.expression, resultVar),
|
|
resultVar: resultVar
|
|
}
|
|
);
|
|
},
|
|
|
|
/*
|
|
* The contract for all code fragments generated by the following functions
|
|
* is as follows:
|
|
*
|
|
* * The code fragment should try to match a part of the input starting with
|
|
* the position indicated in |pos|. That position may point past the end of
|
|
* the input.
|
|
*
|
|
* * If the code fragment matches the input, it advances |pos| after the
|
|
* matched part of the input and sets variable with a name stored in
|
|
* |resultVar| to appropriate value, which is always non-null.
|
|
*
|
|
* * If the code fragment does not match the input, it does not change |pos|
|
|
* and it sets a variable with a name stored in |resultVar| to |null|.
|
|
*/
|
|
|
|
choice: function(node, resultVar) {
|
|
var code = formatCode(
|
|
"var ${resultVar} = null;",
|
|
{ resultVar: resultVar }
|
|
);
|
|
|
|
for (var i = node.alternatives.length - 1; i >= 0; i--) {
|
|
var alternativeResultVar = UID.next("result");
|
|
code = formatCode(
|
|
"${alternativeCode}",
|
|
"if (${alternativeResultVar} !== null) {",
|
|
" var ${resultVar} = ${alternativeResultVar};",
|
|
"} else {",
|
|
" ${code};",
|
|
"}",
|
|
{
|
|
alternativeCode: emit(node.alternatives[i], alternativeResultVar),
|
|
alternativeResultVar: alternativeResultVar,
|
|
code: code,
|
|
resultVar: resultVar
|
|
}
|
|
);
|
|
}
|
|
|
|
return code;
|
|
},
|
|
|
|
sequence: function(node, resultVar) {
|
|
var savedPosVar = UID.next("savedPos");
|
|
|
|
var elementResultVars = PEG.ArrayUtils.map(node.elements, function() {
|
|
return UID.next("result")
|
|
});
|
|
|
|
var code = formatCode(
|
|
"var ${resultVar} = ${elementResultVarArray};",
|
|
{
|
|
resultVar: resultVar,
|
|
elementResultVarArray: "[" + elementResultVars.join(", ") + "]"
|
|
}
|
|
);
|
|
|
|
for (var i = node.elements.length - 1; i >= 0; i--) {
|
|
code = formatCode(
|
|
"${elementCode}",
|
|
"if (${elementResultVar} !== null) {",
|
|
" ${code}",
|
|
"} else {",
|
|
" var ${resultVar} = null;",
|
|
" pos = ${savedPosVar};",
|
|
"}",
|
|
{
|
|
elementCode: emit(node.elements[i], elementResultVars[i]),
|
|
elementResultVar: elementResultVars[i],
|
|
code: code,
|
|
savedPosVar: savedPosVar,
|
|
resultVar: resultVar
|
|
}
|
|
);
|
|
}
|
|
|
|
return formatCode(
|
|
"var ${savedPosVar} = pos;",
|
|
"${code}",
|
|
{
|
|
code: code,
|
|
savedPosVar: savedPosVar
|
|
}
|
|
);
|
|
},
|
|
|
|
labeled: function(node, resultVar) {
|
|
return emit(node.expression, resultVar);
|
|
},
|
|
|
|
simple_and: function(node, resultVar) {
|
|
var savedPosVar = UID.next("savedPos");
|
|
var savedReportMatchFailuresVar = UID.next("savedReportMatchFailuresVar");
|
|
var expressionResultVar = UID.next("result");
|
|
|
|
return formatCode(
|
|
"var ${savedPosVar} = pos;",
|
|
"var ${savedReportMatchFailuresVar} = context.reportMatchFailures;",
|
|
"context.reportMatchFailures = false;",
|
|
"${expressionCode}",
|
|
"context.reportMatchFailures = ${savedReportMatchFailuresVar};",
|
|
"if (${expressionResultVar} !== null) {",
|
|
" var ${resultVar} = '';",
|
|
" pos = ${savedPosVar};",
|
|
"} else {",
|
|
" var ${resultVar} = null;",
|
|
"}",
|
|
{
|
|
expressionCode: emit(node.expression, expressionResultVar),
|
|
expressionResultVar: expressionResultVar,
|
|
savedPosVar: savedPosVar,
|
|
savedReportMatchFailuresVar: savedReportMatchFailuresVar,
|
|
resultVar: resultVar
|
|
}
|
|
);
|
|
},
|
|
|
|
simple_not: function(node, resultVar) {
|
|
var savedPosVar = UID.next("savedPos");
|
|
var savedReportMatchFailuresVar = UID.next("savedReportMatchFailuresVar");
|
|
var expressionResultVar = UID.next("result");
|
|
|
|
return formatCode(
|
|
"var ${savedPosVar} = pos;",
|
|
"var ${savedReportMatchFailuresVar} = context.reportMatchFailures;",
|
|
"context.reportMatchFailures = false;",
|
|
"${expressionCode}",
|
|
"context.reportMatchFailures = ${savedReportMatchFailuresVar};",
|
|
"if (${expressionResultVar} === null) {",
|
|
" var ${resultVar} = '';",
|
|
"} else {",
|
|
" var ${resultVar} = null;",
|
|
" pos = ${savedPosVar};",
|
|
"}",
|
|
{
|
|
expressionCode: emit(node.expression, expressionResultVar),
|
|
expressionResultVar: expressionResultVar,
|
|
savedPosVar: savedPosVar,
|
|
savedReportMatchFailuresVar: savedReportMatchFailuresVar,
|
|
resultVar: resultVar
|
|
}
|
|
);
|
|
},
|
|
|
|
semantic_and: function(node, resultVar) {
|
|
var savedPosVar = UID.next("savedPos");
|
|
|
|
return formatCode(
|
|
"var ${resultVar} = (function() {${actionCode}})() ? '' : null;",
|
|
{
|
|
actionCode: node.code,
|
|
resultVar: resultVar
|
|
}
|
|
);
|
|
},
|
|
|
|
semantic_not: function(node, resultVar) {
|
|
var savedPosVar = UID.next("savedPos");
|
|
|
|
return formatCode(
|
|
"var ${resultVar} = (function() {${actionCode}})() ? null : '';",
|
|
{
|
|
actionCode: node.code,
|
|
resultVar: resultVar
|
|
}
|
|
);
|
|
},
|
|
|
|
optional: function(node, resultVar) {
|
|
var expressionResultVar = UID.next("result");
|
|
|
|
return formatCode(
|
|
"${expressionCode}",
|
|
"var ${resultVar} = ${expressionResultVar} !== null ? ${expressionResultVar} : '';",
|
|
{
|
|
expressionCode: emit(node.expression, expressionResultVar),
|
|
expressionResultVar: expressionResultVar,
|
|
resultVar: resultVar
|
|
}
|
|
);
|
|
},
|
|
|
|
zero_or_more: function(node, resultVar) {
|
|
var expressionResultVar = UID.next("result");
|
|
|
|
return formatCode(
|
|
"var ${resultVar} = [];",
|
|
"${expressionCode}",
|
|
"while (${expressionResultVar} !== null) {",
|
|
" ${resultVar}.push(${expressionResultVar});",
|
|
" ${expressionCode}",
|
|
"}",
|
|
{
|
|
expressionCode: emit(node.expression, expressionResultVar),
|
|
expressionResultVar: expressionResultVar,
|
|
resultVar: resultVar
|
|
}
|
|
);
|
|
},
|
|
|
|
one_or_more: function(node, resultVar) {
|
|
var expressionResultVar = UID.next("result");
|
|
|
|
return formatCode(
|
|
"${expressionCode}",
|
|
"if (${expressionResultVar} !== null) {",
|
|
" var ${resultVar} = [];",
|
|
" while (${expressionResultVar} !== null) {",
|
|
" ${resultVar}.push(${expressionResultVar});",
|
|
" ${expressionCode}",
|
|
" }",
|
|
"} else {",
|
|
" var ${resultVar} = null;",
|
|
"}",
|
|
{
|
|
expressionCode: emit(node.expression, expressionResultVar),
|
|
expressionResultVar: expressionResultVar,
|
|
resultVar: resultVar
|
|
}
|
|
);
|
|
},
|
|
|
|
action: function(node, resultVar) {
|
|
/*
|
|
* In case of sequences, we splat their elements into function arguments
|
|
* one by one. Example:
|
|
*
|
|
* start: a:"a" b:"b" c:"c" { alert(arguments.length) } // => 3
|
|
*
|
|
* This behavior is reflected in this function.
|
|
*/
|
|
|
|
var expressionResultVar = UID.next("result");
|
|
|
|
if (node.expression.type === "sequence") {
|
|
var formalParams = [];
|
|
var actualParams = [];
|
|
|
|
var elements = node.expression.elements;
|
|
var elementsLength = elements.length;
|
|
for (var i = 0; i < elementsLength; i++) {
|
|
if (elements[i].type === "labeled") {
|
|
formalParams.push(elements[i].label);
|
|
actualParams.push(expressionResultVar + "[" + i + "]");
|
|
}
|
|
}
|
|
} else if (node.expression.type === "labeled") {
|
|
var formalParams = [node.expression.label];
|
|
var actualParams = [expressionResultVar];
|
|
} else {
|
|
var formalParams = [];
|
|
var actualParams = [];
|
|
}
|
|
|
|
return formatCode(
|
|
"${expressionCode}",
|
|
"var ${resultVar} = ${expressionResultVar} !== null",
|
|
" ? (function(${formalParams}) {${actionCode}})(${actualParams})",
|
|
" : null;",
|
|
{
|
|
expressionCode: emit(node.expression, expressionResultVar),
|
|
expressionResultVar: expressionResultVar,
|
|
actionCode: node.code,
|
|
formalParams: formalParams.join(", "),
|
|
actualParams: actualParams.join(", "),
|
|
resultVar: resultVar
|
|
}
|
|
);
|
|
},
|
|
|
|
rule_ref: function(node, resultVar) {
|
|
return formatCode(
|
|
"var ${resultVar} = ${ruleMethod}(context);",
|
|
{
|
|
ruleMethod: "parse_" + node.name,
|
|
resultVar: resultVar
|
|
}
|
|
);
|
|
},
|
|
|
|
literal: function(node, resultVar) {
|
|
return formatCode(
|
|
"if (input.substr(pos, ${length}) === ${value|string}) {",
|
|
" var ${resultVar} = ${value|string};",
|
|
" pos += ${length};",
|
|
"} else {",
|
|
" var ${resultVar} = null;",
|
|
" if (context.reportMatchFailures) {",
|
|
" matchFailed(quoteString(${value|string}));",
|
|
" }",
|
|
"}",
|
|
{
|
|
value: node.value,
|
|
length: node.value.length,
|
|
resultVar: resultVar
|
|
}
|
|
);
|
|
},
|
|
|
|
any: function(node, resultVar) {
|
|
return formatCode(
|
|
"if (input.length > pos) {",
|
|
" var ${resultVar} = input.charAt(pos);",
|
|
" pos++;",
|
|
"} else {",
|
|
" var ${resultVar} = null;",
|
|
" if (context.reportMatchFailures) {",
|
|
" matchFailed('any character');",
|
|
" }",
|
|
"}",
|
|
{ resultVar: resultVar }
|
|
);
|
|
},
|
|
|
|
"class": function(node, resultVar) {
|
|
if (node.parts.length > 0) {
|
|
var regexp = "/^["
|
|
+ (node.inverted ? "^" : "")
|
|
+ PEG.ArrayUtils.map(node.parts, function(part) {
|
|
return part instanceof Array
|
|
? PEG.RegExpUtils.quoteForClass(part[0])
|
|
+ "-"
|
|
+ PEG.RegExpUtils.quoteForClass(part[1])
|
|
: PEG.RegExpUtils.quoteForClass(part);
|
|
}).join("")
|
|
+ "]/";
|
|
} else {
|
|
/*
|
|
* Stupid IE considers regexps /[]/ and /[^]/ syntactically invalid, so
|
|
* we translate them into euqivalents it can handle.
|
|
*/
|
|
var regexp = node.inverted ? "/^[\\S\\s]/" : "/^(?!)/";
|
|
}
|
|
|
|
return formatCode(
|
|
"if (input.substr(pos).match(${regexp}) !== null) {",
|
|
" var ${resultVar} = input.charAt(pos);",
|
|
" pos++;",
|
|
"} else {",
|
|
" var ${resultVar} = null;",
|
|
" if (context.reportMatchFailures) {",
|
|
" matchFailed(${rawText|string});",
|
|
" }",
|
|
"}",
|
|
{
|
|
regexp: regexp,
|
|
rawText: node.rawText,
|
|
resultVar: resultVar
|
|
}
|
|
);
|
|
}
|
|
};
|
|
|
|
function emit(node, resultVar) {
|
|
return emitFunctions[node.type](node, resultVar);
|
|
}
|
|
|
|
return emit(ast);
|
|
};
|
|
|
|
})();
|