Re: (lambda ( . rest))

[Reinhold Kainhofer]

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Am Sonntag, 21. Dezember 2008 03:18:48 schrieb Bertalan Fodor:
> Hi,
>
> I found this in lilypond-book-preamble.ly:
>
> (lambda ( . rest)
>
> Besides that I can't imagine what that wants to mean, the GUILE doc
> clearly says:
>
> --- syntax: *lambda* formals body
>
> |(|variable1| ... |variablen| . |variablen+1|)|
>
>     There must be at least one argument before the period.
>
> It seems clear that GUILE accept that strange form. But not any of my
> Java-based parsers.

Neither GUILE nor MIT-Scheme are documented to allow this form of optional 
parameters (actually, both disallow it explicitly in the docs). 

Wouldn't it be better to re-write the code to

#(define toplevel-book-handler
  (lambda rest
  (set! output-empty-score-list #f)
  (apply print-book-with-defaults rest)))

(i.e. name the whole parameter expression rest instead of ( . rest ) and pass 
that on)? I've not tested this, though, so I might be completely wrong,  but 
from the GUILE doc it seems that this does exactly the same as the 
undocumented ( . rest) and is documented to work.

Cheers,
Reinhold

> What would you suggest to do with that?

- -- 
- ------------------------------------------------------------------
Reinhold Kainhofer, Vienna University of Technology, Austria
email: address@hidden, http://reinhold.kainhofer.com/
 * Financial and Actuarial Mathematics, TU Wien, http://www.fam.tuwien.ac.at/
 * K Desktop Environment, http://www.kde.org, KOrganizer maintainer
 * Chorvereinigung "Jung-Wien", http://www.jung-wien.at/
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