jsparsers-compare.js

#! /usr/local/bin/node

var esprima = require("esprima");
var acorn = require("acorn");
var u2 = require("uglify-js2");
var fs = require("fs");

var file = process.argv[2];
var code = fs.readFileSync(file, "utf8");

function time_it(name, cont) {
    var t1 = new Date().getTime();
    var ret = cont();
    var spent = new Date().getTime() - t1;
    console.log("%s: %s", name, (spent / 1000).toFixed(3));
    return ret;
}

time_it("esprima", function(){
    esprima.parse(code, { loc: true, comment: true });
});

time_it("uglifyjs2", function(){
    u2.parse(code);
});

time_it("acorn", function(){
    acorn.parse(code, { locations: true, trackComments: true });
});

// $ cat `~/work/thelib/bin/list-scripts.pl` | jsparsers-compare.js /dev/stdin
// esprima: 0.941
// uglifyjs2: 0.261
// acorn: 0.212