Adding dictionary library.

whalesong/js-assembler/get-runtime.rkt

@@ -42,7 +42,7 @@
                 base64.js
                 
                 baselib.js
-
+                baselib-dict.js
                 baselib-frames.js
 
                 baselib-loadscript.js

whalesong/js-assembler/runtime-src/baselib-dict.js

@@ -0,0 +1,53 @@
+/*jslint unparam: true, vars: true, white: true, newcap: true, nomen: true, plusplus: true, maxerr: 50, indent: 4 */
+
+/*global window*/
+
+// Dictionaries.  We need this due to JS weirdness, since object
+// literals have issues with regards to magic properties like
+// __proto__.  This is taken from Effective JavaScript, Item 45.
+(function (baselib) {
+    'use strict';
+
+    var hasOwnProperty = {}.hasOwnProperty;
+    
+    baselib.Dict = function(elements) {
+        this.elements = elements || {};
+        this.hasSpecialProto = false;
+        this.specialProto = undefined;
+    };
+
+    baselib.Dict.prototype.has = function(key) {
+        if (key === '__proto__') {
+            return this.hasSpecialProto;
+        }
+        return hasOwnProperty.call(this.elements, key);
+    };
+
+    baselib.Dict.prototype.get = function(key) {
+        if (key === '__proto__') { 
+            return this.specialProto;
+        } else if (hasOwnProperty.call(this.elements, key)) {
+            return this.elements[key];
+        } else {
+            return undefined;
+        }
+    };
+
+    baselib.Dict.prototype.set = function(key, val) {
+        if (key === '__proto__') {
+            this.hasSpecialProto = true;
+            this.specialProto = val;
+        } else {
+            this.elements[key] = val;
+        }
+    };
+
+    baselib.Dict.prototype.remove = function(key) {
+        if (key === '__proto__') {
+            this.hasSpecialProto = false;
+            this.specialProto = undefined;
+        } else {
+            delete this.elements[key];
+        }
+    };
+}(window.plt.baselib));