Re: a pure side effect language

[Michael Vanier <address@hidden>]

> Date: Thu, 3 Jul 2003 16:49:28 -0700
> From: James McCartney <asynth@io.com>
> 
> I don't know if anyone here knows about the MAX application, which is 
> used by musicians (there are other ports known as jMAX and PD). It is a 
> boxes and wires style visual language where the boxes are objects and 
> the wires represent message sends to the objects. The message sends are 
> implemented as C function calls passing a list of tagged argument 
> values.
> 
> The interesting thing about this language is that is probably as far 
> from functional as you can get. It is a pure side effect language. The 
> function calls do not return a value. Therefore it can only do anything 
> by mutating an object or causing i/o. There are no variables per se, 
> but there are objects in which you can store a value by sending it a 
> message, and get the stored value out by sending a message.
> 

Of course, even pure functional languages can compute without returning
values if you use continuation-passing style (CPS).  A standard compiler
trick for some languages is to convert regular function calls to CPS.  You
also need tail call elimination for this to work.

Mike