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nwronskinwronski
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Merge branch 'tracer'
# Conflicts: # Gruntfile.js # demo/js/sqlite-parser-demo.js # dist/sqlite-parser-min.js # dist/sqlite-parser.js # index.js # lib/parser.js # package.json # test/index-spec.js
2 parents dd25059 + bc5536a commit b5f41fc

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‎CHANGELOG.md‎

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All notable changes to this project will be documented in this file.
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## [Unreleased][unreleased]
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### Changed
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- Created a `tracer` branch to continue developing the `Tracer` class into something viable.
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## [v0.12.0-beta.1] - 2015-09-29
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### Changed

‎Gruntfile.js‎

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options: {
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failOnError: true
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},
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command: './node_modules/.bin/pegjs --optimize speed src/grammar.pegjs lib/parser.js'
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command: './node_modules/.bin/pegjs --trace src/grammar.pegjs lib/parser.js'
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},
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test: {
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options: {

‎README.md‎

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[![devDependencies Status Image](https://img.shields.io/david/dev/codeschool/sqlite-parser.svg)](https://github.com/codeschool/sqlite-parser/)
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[![License Type Image](https://img.shields.io/github/license/codeschool/sqlite-parser.svg)](https://github.com/codeschool/sqlite-parser/blob/master/LICENSE)
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## This branch is a work-in-progress
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_Note: There is a currently a significant performance penalty (14x) to using this branch for the smart-error functionality._
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This library parses SQLite queries, using JavaScript, and generates
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_abstract syntax tree_ (AST) representations of the input strings. A
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syntax error is produced if an AST cannot be generated.
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});
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```
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## Syntax Errors
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This parser uses the `--trace` flag exposed in `pegjs` to create "smart" error
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messages. The parser includes a `Trace` class that keeps track of which grammar
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rules were being traversed just prior to the error and uses that information
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to improve the error message and location information.
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## AST
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**NOTE: The SQLite AST is a work-in-progress and subject to change.**

‎index.js‎

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/**
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* sqlite-parser
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* @copyright Code School 2015 {@link http://codeschool.com}
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* @author Nick Wronski <nick@javascript.com>
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*/
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var parser = require('./lib/parser');
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var parser = require('./lib/parser'),
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Tracer = require('./lib/tracer');
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function sqliteParser(source, callback) {
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var t = Tracer(), res;
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try {
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callback(null, parser.parse(source));
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res = parser.parse(source, {
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'tracer': t
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});
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callback(null, res);
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} catch (e) {
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callback(e);
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callback(e instanceof parser.SyntaxError ? t.smartError(e) : e);
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}
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}
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‎lib/tracer.js‎

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/*!
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* sqlite-parser
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* @copyright Code School 2015 {@link http://codeschool.com}
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* @author Nick Wronski <nick@javascript.com>
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*/
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var parserUtils = require('./parser-util');
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module.exports = (function (util) {
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Tracer = function Tracer() {
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if (!(this instanceof Tracer)) {
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return new Tracer();
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}
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this.events = [];
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this.indentation = 0;
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this.whitespaceRule = /(^whitespace)|(char$)|(^[oe]$)/i;
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this.statementRule = /Statement$/i;
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this.firstNodeRule = /(Statement|Clause)$/i;
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};
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Tracer.prototype.trace = function trace(event) {
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var that = this, lastIndex, lastWsIndex;
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event.indentation = this.indentation;
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switch (event.type) {
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case 'rule.enter':
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// add entered leaf
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this.events.push(event);
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this.indentation += 1;
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break;
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case 'rule.match':
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this.indentation -= 1;
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break;
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case 'rule.fail':
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// remove failed leaf
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lastIndex = util.findLastIndex(this.events, {rule: event.rule});
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lastWsIndex = util.findLastIndex(this.events, function (e) {
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return !that.whitespaceRule.test(e.rule);
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});
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if (that.whitespaceRule.test(event.rule) || lastIndex === lastWsIndex) {
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this.events.splice(lastIndex, 1);
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}
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this.indentation -= 1;
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break;
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}
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};
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/**
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* @note
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* There is way too much magic/nonsense in this method now. Need to
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* come up with an alternative approach to getting the right
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* information for syntax errors.
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*/
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Tracer.prototype.smartError = function smartError(err) {
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var that = this, message, location, chain, chainDetail, firstNode,
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bestNode = {indentation: -1}, deep = false, stmts = 0,
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namedEvents = this.events
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.filter(function (e) {
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return e.description !== null &&
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!that.whitespaceRule.test(e.rule);
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})
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.reverse();
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chain = util.takeWhile(namedEvents, function (elem) {
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if (/^(sym\_semi)$/i.test(elem.rule)) {
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stmts += 1;
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}
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if (stmts > 1) {
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return false;
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}
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if (!deep) {
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if (elem.indentation > bestNode.indentation) {
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bestNode = elem;
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} else {
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deep = true;
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}
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} else if (/^(stmt)$/i.test(elem.rule)) {
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deep = true;
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return true;
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}
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return true;
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});
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if (chain.length) {
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location = bestNode.location;
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firstNode = util.findWhere(chain, function (elem) {
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return that.firstNodeRule.test(elem.description) &&
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elem.description !== bestNode.description &&
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elem.indentation !== bestNode.indentation;
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});
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if (firstNode != null) {
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if (this.statementRule.test(bestNode.description) &&
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this.statementRule.test(firstNode.description)) {
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chainDetail = firstNode.description;
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} else {
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chainDetail = bestNode.description + ' (' + firstNode.description + ')';
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}
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} else {
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chainDetail = bestNode.description;
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}
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message = 'Syntax error found near ' + chainDetail;
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util.extend(err, {
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'message': message,
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'location': location
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});
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}
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return err;
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};
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return Tracer;
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})(parserUtils);

‎package.json‎

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"load-grunt-tasks": "^3.3.0",
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"lodash": "^3.10.0",
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"mocha": "^2.2.5",
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"pegjs": "git+https://github.com/dmajda/pegjs.git#master",
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"pegjs": "git+https://github.com/nwronski/pegjs.git#master",
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"prettyjson": "^1.1.2",
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"promise": "^7.0.3"
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},

‎src/tracer.js‎

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/*!
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* sqlite-parser
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* @copyright Code School 2015 {@link http://codeschool.com}
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* @author Nick Wronski <nick@javascript.com>
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*/
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var parserUtils = require('./parser-util');
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module.exports = (function (util) {
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Tracer = function Tracer() {
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if (!(this instanceof Tracer)) {
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return new Tracer();
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}
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this.events = [];
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this.indentation = 0;
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this.whitespaceRule = /(^whitespace)|(char$)|(^[oe]$)/i;
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this.statementRule = /Statement$/i;
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this.firstNodeRule = /(Statement|Clause)$/i;
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};
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Tracer.prototype.trace = function trace(event) {
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var that = this, lastIndex, lastWsIndex;
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event.indentation = this.indentation;
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switch (event.type) {
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case 'rule.enter':
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// add entered leaf
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this.events.push(event);
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this.indentation += 1;
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break;
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case 'rule.match':
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this.indentation -= 1;
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break;
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case 'rule.fail':
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// remove failed leaf
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lastIndex = util.findLastIndex(this.events, {rule: event.rule});
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lastWsIndex = util.findLastIndex(this.events, function (e) {
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return !that.whitespaceRule.test(e.rule);
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});
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if (that.whitespaceRule.test(event.rule) || lastIndex === lastWsIndex) {
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this.events.splice(lastIndex, 1);
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}
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this.indentation -= 1;
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break;
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}
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};
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/**
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* @note
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* There is way too much magic/nonsense in this method now. Need to
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* come up with an alternative approach to getting the right
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* information for syntax errors.
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*/
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Tracer.prototype.smartError = function smartError(err) {
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var that = this, message, location, chain, chainDetail, firstNode,
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bestNode = {indentation: -1}, deep = false, stmts = 0,
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namedEvents = this.events
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.filter(function (e) {
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return e.description !== null &&
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!that.whitespaceRule.test(e.rule);
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})
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.reverse();
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chain = util.takeWhile(namedEvents, function (elem) {
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if (/^(sym\_semi)$/i.test(elem.rule)) {
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stmts += 1;
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}
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if (stmts > 1) {
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return false;
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}
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if (!deep) {
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if (elem.indentation > bestNode.indentation) {
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bestNode = elem;
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} else {
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deep = true;
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}
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} else if (/^(stmt)$/i.test(elem.rule)) {
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deep = true;
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return true;
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}
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return true;
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});
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if (chain.length) {
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location = bestNode.location;
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firstNode = util.findWhere(chain, function (elem) {
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return that.firstNodeRule.test(elem.description) &&
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elem.description !== bestNode.description &&
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elem.indentation !== bestNode.indentation;
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});
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if (firstNode != null) {
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if (this.statementRule.test(bestNode.description) &&
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this.statementRule.test(firstNode.description)) {
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chainDetail = firstNode.description;
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} else {
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chainDetail = bestNode.description + ' (' + firstNode.description + ')';
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}
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} else {
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chainDetail = bestNode.description;
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}
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message = 'Syntax error found near ' + chainDetail;
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util.extend(err, {
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'message': message,
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'location': location
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});
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}
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return err;
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};
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return Tracer;
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})(parserUtils);

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