Re: [Chicken-users] Limitation of Chicken's keyword arguments

[Kon Lovett]

On Apr 1, 2008, at 3:01 PM, Luke McCarthy wrote:
> Keyword arguments in Chicken don't work where the keywords precede  
> the rest
> list, e.g. (a href: "url" "text").
>
> (define (a #!rest args #!key href) ...)
>
> In the call (a href: "foo" "bar") href is bound to "foo" as  
> expected but args
> is bound to (href: "foo" "bar") not ("bar").

It works as documented, just not as desired.

> The behaviour makes sense from the point of view of the  
> implementation. It
> would be less efficient to support the idiom since the rest list  
> would have
> to be post-processed to remove keyword arguments.
>
> It might be worth noting that Python's keyword arguments are  
> limited in the
> same way (but throw exceptions instead).
>
> I suppose it would not be much trouble to write a macro (like let- 
> optionals)
> to get the behaviour you wanted. I just thought it might be worth  
> metioning
> or discussing.

See "misc-extn-dsssl" for some support procedures.

> Luke
>
>
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Best Wishes,
Kon