jison2json.js

#!/usr/bin/env node

// Encodes Jison formatted grammars as JSON

var fs = require('fs');
var path = require('path');
var bnfParser = require('ebnf-parser');
var lexParser = require('lex-parser');

exports.main = function (argv) {
    if(argv.length == 1) return;

    var args = argv.slice(1);
    var bnf, lex;

    console.log(args);

    if (args.length) {
        bnf = fs.readFileSync(path.resolve(args[0]), 'utf8');
        if (args[1]) {
        console.log('???lex');
            lex = fs.readFileSync(path.resolve(args[1]), 'utf8');
        }

        console.log(processGrammar(bnf, lex));
    } else {
        var read = false;
        input(function (bnf) {
            read = true;
            console.log(processGrammar(bnf));
        });
    }
};

exports.convert = processGrammar;

function processGrammar (rawGrammar, lex) {
    var grammar = bnfParser.parse(rawGrammar);
    if (lex) grammar.lex = lexParser.parse(lex);

    // trick to reposition `bnf` after `lex` in serialized JSON
    grammar.bnf = grammar.bnf;

    return JSON.stringify(grammar, null, '  ');
}

function input (cb) {
    var stdin = process.openStdin(),
        data = '';

    stdin.setEncoding('utf8');
    stdin.addListener('data', function (chunk) {
        data += chunk;
    });
    stdin.addListener('end', function () {
        cb(data);
    });
};

if (require.main === module)
    exports.main(process.argv.slice(1));