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POIs there a hashmap library for JavaScript?
 

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    <p>In JavaScript, all Objects act a bit like hashmaps. However, the keys to these hashmaps must be strings. If they're not, they're converted with <code>toString()</code>. That means:</p> <pre><code>var a = {foo: 1}; var b = {bar: 2}; var o = {}; o[a] = 100; o[b]; // 100 JSON.stringify(o); // '{"[object Object]":100}' </code></pre> <p>That is, since the <code>toString()</code> of any plain Object is <code>[object Object]</code>, they all address the same value.</p> <p>I'd like to create a hashmap where Objects with the same properties and values address the same value, but objects with different properties or values address different values. That is:</p> <pre><code>var a = {foo: 1}; var b = {bar: 2, baz: 3}; var c = {baz: 3, bar: 2}; var hash = new Hash(); hash.set(a, 100); hash.get(b); // undefined hash.set(b, 200); hash.get(b); // 200 hash.get(c); // 200 </code></pre> <p>My first instinct was to use <code>JSON.stringify()</code> to turn objects into strings, but:</p> <pre><code>var hash = {}; var b = {bar: 2, baz: 3}; var c = {baz: 3, bar: 2}; hash[JSON.stringify(b)] = 100 hash[JSON.stringify(b)] // 100 hash[JSON.stringify(c)] // undefined JSON.stringify(b) // '{"bar":2,"baz":3}' JSON.stringify(c) // '{"baz":3,"bar":2}' </code></pre> <p>That is, JSON serialization is order-dependent.</p> <p>Is there a good library or technique to implement a hashmap like this?</p> <p><strong>Update</strong>:</p> <p>Equivalently, is there a good hashing function such that:</p> <pre><code>hash({foo: 1, bar: 2}) == hash({bar: 2, foo: 1}) </code></pre>
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