Re: "procedure" vs. "function"

[Wols Lists]

On 18/04/15 16:21, Urs Liska wrote:
> So the choice of these names is actually an inconsistency in LilyPond's
> terminology?
> 
> I'm asking this because I have just completed a tutorial about
> define-music-function and its siblings, and I realized that I used the
> terms function and procedure in an arbitrary mix.
> 
> Now I think that I should follow the consistency of the Guile manual ,
> use "procedure" everywhere in my text and point out the inconsistency in
> naming.

I notice you're talking about functions and procedures, where other
people have been talking about functions and subroutines.

As I understand it, they're all procedures - a procedure is an external
section of code. A procedure may be a subroutine, that does not return a
value but CAN have side effects (ie modify non-local memory). A
function, on the other hand, does everything locally, has no side
effects, and returns its result. What you call a procedure that has side
effects AND returns a value is undefined ... :-)

Cheers,
Wol