Re: [Chicken-users] is case-lambda expensive?

[Kon Lovett]

On May 24, 2006, at 10:33 AM, Matthew David Parker wrote:

> > Ex: (w/ csi)
> >
> > #;1> (define (msdl.pixel x y rgb alpha #!optional (img 0)) 'foo)
> > #;2> (procedure-information msdl.pixel)
> > (msdl.pixel x y rgb alpha #!optional (img 0))
> > #;3> (msdl.pixel 3)
> > Error: too few arguments - received 1 but expected 4: #<procedure
> > (msdl.pixel x y rgb alpha #!optional (img 0))>
> >
> >          Call history:
> >
> >          <eval>          (msdl.pixel 3)  <--
>
> That is just want I want; for it to throw an error and then print  
> out the
> info, but I have to define and compile my functions in csc first,  
> so I get
> the weird errors will all the numbers after them.  Is there some  
> way to
> clean up the debug output from functions that come from csc?

I don't think so. I don't see an 'invalid-procedure-call-arity- 
handler.' And the name of the optional is lost w/ the compiler. Umm,  
hook 'error'? Sorry.

> Is it better
> to use the #!optional thing instead of case-lambda? (I have to use  
> one of
> those for the img argument at least).

Hum, "better." Funny, for a "small" programming notation Scheme seems  
to have an almost Perl-like mania for multiple ways to do the same  
thing.

Personal style & portability.

case-lambda can be repetitive & no support for named arguments but it  
is a srfi.

I find the DSSSL lambdas easier to read, but NOT portable. (Marc  
Feeley has a draft srfi-89 to replace DSSSL w/ a more scheme-like  
notation.)

I think 'let-optionals' & ':optional' are by Olin Shivers from Scsh,  
and rather common.

> Matt
>
>
> > And (w/ csc)
> >
> > Error: too few arguments - received 1 but expected 4: #<procedure
> > (msdl.pixel x3 y4 rgb5 alpha6 . g27)>
> >
> >          Call history:
> >
> >          t1.scm: 3    msdl.pixel                 <--
> >
> > > Thanks,
> > > Matt
> > >
> > > (btw, "msdl" is just a temporary name, as there is already an
> > > "msdl" for
> > > SDL)
> > >
> > >
> > > _______________________________________________
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> > > http://lists.nongnu.org/mailman/listinfo/chicken-users
>
>
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