TiddlyWiki5/js/JavaScriptParser.js

/*\
title: js/JavaScriptParser.js

Parses JavaScript source code into a parse tree using PEGJS

\*/
(function(){

/*jslint node: true */
"use strict";

var WikiTextParseTree = require("./WikiTextParseTree.js").WikiTextParseTree,
    Renderer = require("./Renderer.js").Renderer,
    Dependencies = require("./Dependencies.js").Dependencies,
    esprima = require("esprima");

// Initialise the parser
var JavaScriptParser = function(options) {
    this.store = options.store;
};

// Parse a string of JavaScript code or JSON and return the parse tree as a wikitext parse tree
JavaScriptParser.prototype.parse = function(type,code) {
	var parseTree,
		result = [],
		t,endLastToken = 0;
	// Try to parse the code
	try {
		parseTree = esprima.parse(code,{tokens: true,range: true});
	} catch(ex) {
		// Return a helpful error if the parse failed
		return new WikiTextParseTree([
			Renderer.ElementNode("pre",{"class": "javascript-source"},[
				Renderer.TextNode(code.substring(0,ex.index)),
				Renderer.ErrorNode(ex),
				Renderer.TextNode(code.substring(ex.index))
			])
		],new Dependencies(),this.store);
	}
	// Render the tokens with the appropriate class
	for(t=0; t<parseTree.tokens.length; t++) {
		var token = parseTree.tokens[t];
		if(token.range[0] > endLastToken) {
			result.push(Renderer.TextNode(code.substring(endLastToken,token.range[0])));
		}
		result.push(Renderer.ElementNode("span",{
			"class": "javascript-" + token.type.toLowerCase()
		},[
			Renderer.TextNode(token.value)
		]));
		endLastToken = token.range[1] + 1;
	}
	if(endLastToken < code.length) {
		result.push(Renderer.TextNode(code.substring(endLastToken)));
	}
	return new WikiTextParseTree([
			Renderer.ElementNode("pre",{"class": "javascript-source"},result)
		],new Dependencies(),this.store);
};

exports.JavaScriptParser = JavaScriptParser;

})();