1 files changed, 91 insertions, 0 deletions
diff --git a/src/sdlang/libinputvisitor/libInputVisitor.d b/src/sdlang/libinputvisitor/libInputVisitor.d
new file mode 100644
index 0000000..15c2ce8
--- /dev/null
+++ b/src/sdlang/libinputvisitor/libInputVisitor.d
@@ -0,0 +1,91 @@
+/++
+Copyright (C) 2012 Nick Sabalausky <http://semitwist.com/contact>
+
+This program is free software. It comes without any warranty, to
+the extent permitted by applicable law. You can redistribute it
+and/or modify it under the terms of the Do What The Fuck You Want
+To Public License, Version 2, as published by Sam Hocevar. See
+http://www.wtfpl.net/ for more details.
+
+	DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE 
+				Version 2, December 2004 
+
+Copyright (C) 2004 Sam Hocevar <sam@hocevar.net> 
+
+Everyone is permitted to copy and distribute verbatim or modified 
+copies of this license document, and changing it is allowed as long 
+as the name is changed. 
+
+		DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE 
+TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 
+
+0. You just DO WHAT THE FUCK YOU WANT TO.
++/
+
+/++
+Should work with DMD 2.059 and up
+
+For more info on this, see:
+http://semitwist.com/articles/article/view/combine-coroutines-and-input-ranges-for-dead-simple-d-iteration
++/
+
+import core.thread;
+
+class InputVisitor(Obj, Elem) : Fiber
+{
+	bool started = false;
+	Obj obj;
+	this(Obj obj)
+	{
+		this.obj = obj;
+		super(&run);
+	}
+
+	private void run()
+	{
+		obj.visit(this);
+	}
+	
+	private void ensureStarted()
+	{
+		if(!started)
+		{
+			call();
+			started = true;
+		}
+	}
+	
+	// Member 'front' must be a function due to DMD Issue #5403
+	private Elem _front;
+	@property Elem front()
+	{
+		ensureStarted();
+		return _front;
+	}
+	
+	void popFront()
+	{
+		ensureStarted();
+		call();
+	}
+	
+	@property bool empty()
+	{
+		ensureStarted();
+		return state == Fiber.State.TERM;
+	}
+	
+	void yield(Elem elem)
+	{
+		_front = elem;
+		Fiber.yield();
+	}
+}
+
+template inputVisitor(Elem)
+{
+	@property InputVisitor!(Obj, Elem) inputVisitor(Obj)(Obj obj)
+	{
+		return new InputVisitor!(Obj, Elem)(obj);
+	}
+}