optassoarray.d

struct optassoarray(V, K) {
	struct triple {
		ulong index;
		K key;
		V value;
		auto tuple(){
			import std.typecons:t=tuple;
			return t(index,key,value);
		}
	}
	struct _pair {
		V value;
		K key;
	}
	_pair[] array;
	triple opIndex(ulong index) {
		return triple(index, array[index].key, array[index].value);
	}
	triple opIndex(K key) {
		foreach (i, pair; array) {
			if (pair.key == key) {
				return triple(i, pair.key, pair.value);
			}
		}
		return triple(-1, K.init, V.init);
	}
	ulong length() {
		return array.length;
	}
	void opIndexAssign(V value, K key) {
		foreach (i, pair; array) {
			if (pair.key == key) {
				array[i].value = value;
				return;
			}
		}
		array ~= _pair(value, key);
	}
	void opOpAssign(string s:"~")(V value){
		array~=_pair(value,K.init);
	}
	auto torange(){
		import std.range;
		alias T=typeof(&this);
		alias Iota=typeof(iota(0,ulong(10)));
		struct range{
			T parent;
			Iota i;
			triple front(){
				return (*parent)[i.front];
			}
			void popFront(){
				i.popFront;
			}
			bool empty(){
				return i.empty;
			}
		}
		return range(&this,iota(0,length));
	}
}

unittest {
	optassoarray!(int, string) foo;
	foo ~= 1;
	foo["foo"] = 2;
	foo ~= 3;
	assert(foo[0].value == 1);
	assert(foo[0].key == string.init);
	assert(foo[2].value == 3);
	assert(foo[2].key == string.init);
	assert(foo["foo"].index == 1);
	assert(foo["foo"].value == 2);
	import std;
	foreach(index,key,value; foo.torange.map!(a=>a.tuple)) {
		writeln(index,"(",key,"):",value);
	}
}