Re: [q-lang-users] RFC: Conditional syntax

[Albert G. <Dr....@t-...>]

Patrick Albuquerque wrote:
>     abs X    = choose (X<0, -X; true, X);

Keith Trenton wrote:
 >      abs X    = branch (X<0, -X; true, X);

I like those. "choose" seems to be a bit too generic, though, and thus 
it might collide with user definitions (I actually have a few programs 
where I use that for nondeterministic choice). That also rules out 
"test", I guess. But "branch" seems to be ok.

Keith and Brian, thanks for your other suggestions, too. But those 
abbreviations sound an awful lot like assembler opcodes... ;-)

Ok, here is what we got so far:

1. cop, coop, co_op
2. mbr
3. choose
4. branch

Here are some more I "invented" myself:

5. pick
6. check
7. test
8. query
9. guard

BTW, in the library of the Icon language, Dijkstra-style guarded 
statements are named if_fi, but this also looks a bit clumsy.

Or how about:

10. ifcond

This is sufficiently similar to cond, not likely to collide with user 
definitions, and we already have ifelse for the two-way conditional.

Of course, the question is whether we actually need this construct at 
all, since one could always use an if-then-else if-... chain like in 
other programming languages:

sign X = if X<0 then -X
          else if X>0 then X
          else X;

Hmm ... actually, that looks quite messy when compared to:

sign X = ifcond (X<0, -X; X>0, X; true, 0);

I can understand now why Lisp programmers love their cond. ;-)

Comments? Other suggestions?

Albert

-- 
Dr. Albert Gr"af
Dept. of Music-Informatics, University of Mainz, Germany
Email:  Dr....@t-..., ag...@mu...
WWW:    http://www.musikinformatik.uni-mainz.de/ag