A case for let-optionals and let-keywords (Was: Re: [scheme-reports-wg2] Re: R7RS-large backward compatibility)
Amirouche Boubekki 08 Mar 2020 22:30 UTC
Le dim. 8 mars 2020 à 22:58, John Cowan <xxxxxx@ccil.org> a écrit :
> In my view, R6RS failed to spread to R5RS+ implementations (other than those maintained by members of the editorial committee) precisely because it demanded too much change from them. I don't want to happen to R7RS, and the evidence is that so far it has not. I'd like to keep it that way.
>
> Comments and corrections?
The syntax of SRFI-177 is too heavy, and it requires to learn new
things in scheme.
So far the arguments in favor of keywords like SRFI-177 are:
- Performance
- Programming in the large
- Scripting
In scripting, performance does not really matter. In programming in
the large, companies can invest in better compilers.
That is case of for let-optionals and let-keywords (or similar
approach relying on rest arguments). This does not introduce a new
syntax, it is a good uses case for macros, it is portable, it does not
introduce new things to implement in scheme standard and the syntax is
clean.
What precludes those macros as keywords facility and as the way-to-go
for R7RS libraries?
> John Cowan http://vrici.lojban.org/~cowan xxxxxx@ccil.org
> We want more school houses and less jails; more books and less arsenals;
> more learning and less vice; more constant work and less crime; more
> leisure and less greed; more justice and less revenge; in fact, more of
> the opportunities to cultivate our better natures. --Samuel Gompers
Thanks in advance