Lua: Add native/haxe iterator helpers

std/lua/HaxeIterator.hx

@@ -0,0 +1,42 @@
+/*
+ * Copyright (C)2005-2016 Haxe Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+package lua;
+
+/**
+  An implementation of the haxe iterator datastructure needed for identical 
+  lua iterator behavior. 
+ **/
+class HaxeIterator<T> {
+	var state : T;
+	var f : Void->T;
+	public function new(f:Void->T){
+		this.f = f;
+		this.state = f();
+	}
+	public function next(){
+		var ret = this.state;
+		this.state = this.f();
+		return ret;
+	}
+	public function hasNext() return this.state != null;
+}

std/lua/NativeIterator.hx

@@ -0,0 +1,45 @@
+/*
+ * Copyright (C)2005-2016 Haxe Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+package lua;
+
+/**
+	This abstract enables easy conversion from basic lua iterators
+	(i.e., a function that is called until it returns null), and 
+	Haxe iterators, which provide a next/hasNext interface.
+**/
+abstract NativeIterator<T>(HaxeIterator<T>) {
+	public function new(f : Void->T) {
+		this = new HaxeIterator(f);
+	}
+
+	@:from
+	public static function fromF<T>(f : Void->T){
+		return new NativeIterator(f);
+	}
+
+	@:to
+	public function toF() : Iterator<T> {
+		return this;
+	}
+}
+