Add more Map/Set fast paths for more primitives: boolean, null, u…

…ndefined.
paulmillr · May 29, 2015 · db7a093 · db7a093
1 parent f904808
commit db7a093
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Showing 2 changed files with 30 additions and 10 deletions.
diff --git a/es6-shim.js b/es6-shim.js
@@ -1945,14 +1945,18 @@
         return null;
       }
       var type = typeof key;
-      if (type === 'string') {
+      if (type === 'undefined' || key === null) {
+        return '^' + String(key);
+      } else if (type === 'string') {
         return '$' + key;
       } else if (type === 'number') {
         // note that -0 will get coerced to "0" when used as a property key
         if (!preservesNumericInsertionOrder) {
           return 'n' + key;
         }
         return key;
+      } else if (type === 'boolean') {
+        return 'b' + key;
       }
       return null;
     };
@@ -2280,13 +2284,21 @@
           if (!set['[[SetData]]']) {
             var m = set['[[SetData]]'] = new collectionShims.Map();
             _forEach(Object.keys(set._storage), function (k) {
-              // fast check for leading '$'
-              if (k.charCodeAt(0) === 36) {
-                k = k.slice(1);
-              } else if (k.charAt(0) === 'n') {
-                k = +k.slice(1);
+              if (k === '^null') {
+                k = null;
+              } else if (k === '^undefined') {
+                k = void 0;
               } else {
-                k = +k;
+                var first = k.charAt(0);
+                if (first === '$') {
+                  k = k.slice(1);
+                } else if (first === 'n') {
+                  k = +k.slice(1);
+                } else if (first === 'b') {
+                  k = k === 'btrue';
+                } else {
+                  k = +k;
+                }
               }
               m.set(k, k);
             });

diff --git a/test/collections.js b/test/collections.js
@@ -817,15 +817,15 @@ describe('Collections', function () {
 
       var set;
       beforeEach(function () {
-        set = new Set([1, NaN, false]);
+        set = new Set([1, NaN, false, true, null, undefined, 'a']);
       });
 
       afterEach(function () {
         set = null;
       });
 
       it('works with the full set', function () {
-        expect(Array.from(set)).to.eql([1, NaN, false]);
+        expect(Array.from(set)).to.eql([1, NaN, false, true, null, undefined, 'a']);
       });
 
       it('works with Set#keys()', function () {
@@ -837,7 +837,15 @@ describe('Collections', function () {
       });
 
       it('works with Set#entries()', function () {
-        expect(Array.from(set.entries())).to.eql([[1, 1], [NaN, NaN], [false, false]]);
+        expect(Array.from(set.entries())).to.eql([
+          [1, 1],
+          [NaN, NaN],
+          [false, false],
+          [true, true],
+          [null, null],
+          [undefined, undefined],
+          ['a', 'a']
+        ]);
       });
     });