using acorn, faster from 700ms to 560ms to parse jquery

.gitignore

@@ -1 +1,2 @@
 node_modules
+bench/src/jquery.js

.npmignore

@@ -0,0 +1 @@
+bench/src/jquery.js

bench/detect.js

@@ -0,0 +1,7 @@
+var detective = require('../');
+var fs = require('fs');
+
+var src = fs.readFileSync(__dirname + '/src/jquery.js', 'utf8');
+var t0 = Date.now();
+var requires = detective(src);
+console.log(Date.now() - t0);

bench/esprima_v_acorn.txt

@@ -0,0 +1,18 @@
+esprima:
+
+  $ for i in {1..5}; do node detect.js; done
+  704
+  702
+  704
+  704
+  697
+
+acorn:
+
+  $ for i in {1..5}; do node detect.js; done
+  555
+  552
+  585
+  549
+  583
+

index.js

@@ -1,4 +1,20 @@
-var esprima = require('esprima-fb');
+var aparse = require('acorn').parse;
+var defined = require('defined');
+
+function parse (src, opts) {
+    if (!opts) opts = {};
+    return aparse(src, {
+        ecmaVersion: defined(opts.ecmaVersion, 6),
+        ranges: defined(opts.ranges, opts.range),
+        locations: defined(opts.locations, opts.loc),
+        allowReturnOutsideFunction: defined(
+            opts.allowReturnOutsideFunction, true
+        ),
+        strictSemicolons: defined(opts.strictSemicolons, false),
+        allowTrailingCommas: defined(opts.allowTrailingCommas, true),
+        forbidReserved: defined(opts.forbidReserved, false)
+    });
+}
 var escodegen = require('escodegen');
 
 var traverse = function (node, cb) {
@@ -22,7 +38,7 @@ var traverse = function (node, cb) {
 };
 
 var walk = function (src, opts, cb) {
-    var ast = esprima.parse(src, opts);
+    var ast = parse(src, opts);
     traverse(ast, cb);
 };
 

package.json

@@ -17,6 +17,7 @@
     "test": "tap test/*.js"
   },
   "dependencies": {
+    "defined": "0.0.0",
     "escodegen": "~1.1.0",
     "esprima-fb": "4001.1.0-dev-harmony-fb"
   },

test/files/yield.js

@@ -1,2 +1,4 @@
-var a = require('a');
-var b = yield require('c')(a);
+(function * () {
+    var a = require('a');
+    var b = yield require('c')(a);
+})();