シンプルなキャッシュの例

cache_sample.js

var list = function(val) { 
    if(!list.cache.hasOwnProperty(val)) { 
      list.cache[val] = val; 
    } 
    return list.cache[val]; 
}
list.cache = {};

list("foo");
list.cache["foo"] == "foo";


list("var");
list.cache["var"] == "var";