parser.js

/**
 * Copyright (c) 2017, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
 *
 * WSO2 Inc. licenses this file to you under the Apache License,
 * Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
var antlr4 = require('antlr4');
var BallerinaLexer = require('./antlr-gen/BallerinaLexer');
var BallerinaParser = require('./antlr-gen/BallerinaParser');
var BLangParserErrorListener = require('./error-listener').BLangParserErrorListener;
var BLangParserListener = require('./listener').BLangParserListener;

/**
 * Entry point for client side antlr based parser for ballerina
 *
 * @constructor
 */
var Parser = function() {
};

/**
 * Creates AST for the given ballerina source
 * @param input {string} ballerina source content
 */
Parser.prototype.parse = function(input){
    // setup parser
    var chars = new antlr4.InputStream(input);
    var lexer = new BallerinaLexer.BallerinaLexer(chars);
    var tokens  = new antlr4.CommonTokenStream(lexer);
    var parser = new BallerinaParser.BallerinaParser(tokens);
    var listener = new BLangParserListener(parser);

    // set custom error listener for collecting syntax errors
    var errorListener = new BLangParserErrorListener();
    parser.removeErrorListeners();
    parser.addErrorListener(errorListener);

    // start parsing
    var tree = parser.compilationUnit();

    antlr4.tree.ParseTreeWalker.DEFAULT.walk(listener, tree);

    // return collected errors
    return errorListener.getErrors();
};

exports.Parser = Parser;