gistfile1.js

  		set: function (collection) {
				// returns a set (as a list...) from a collection
				// in other words, uniques
				var o = {}, r = [], l = collection.length, i = 0;
				for (; i < l; i++) {
					if (!(collection[i] in o)) {
						o[collection[i]] = true;
						r.push(collection[i]);
					}
				}
				return r;
			},
			map: function (collection, lambda) {
				// maps a collection by a lambda
				var r = [], i = 0; l = collection.length;
				for (; i < l; i++) {
					r.push(lambda(collection[i]));
				}
				return r;
			},
			filter: function (collection, predicate) {
				// filters a collection according to a predicate
				var r = [], i = 0, l = collection.length;
				for (; i < l; i++) {
					if (predicate(collection[i])) {
						r.push(collection[i]);
					}
				}
				return r;
			},
			all: function (collection) {
				// equvalent of python's all()
				return this.filter(collection, function (el) { return !!el; });
			},
			nall: function (collection) {
				// reverse of all()
				return this.filter(collection, function (el) { return !!!el; });
			}