Try Plumb
Plumb has a Javascript
implementation, so we can try it right in the browser (as long as it
supports Javascript!)
To try out Plumb, you can write Javascript code in these boxes. For
security reasons, only code following the JSON sub-set of
Javascript will be accepted, although Plumb itself can work with
arbitrary code.
The code in the top box will be given interpreted by
plumb to produce a Javascript function. The contents of the
second box will be sent as an argument to this function, and the return
value will appear in the bottom box.