Re: Breaking hygiene with syntax-rules?

[Jean Abou Samra <jean@abou-samra.fr>]

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Le vendredi 11 août 2023 à 10:33 +0200, Dr. Arne Babenhauserheide a écrit :
> 
> Jean Abou Samra <jean@abou-samra.fr> writes:
> 
> > This is a known limitation in Guile. Please read
> > https://www.gnu.org/software/guile/manual/html_node/Hygiene-and-the-Top_002dLevel.html
> 
> I would not expect that effect from the description, because in
> 
> (define-syntax unhygienic
>   (syntax-rules ()
>     ((_ the-pair fetch)
>      (begin
>        (define the-head (car the-pair))
>        (define (the-proc) the-head)
>        (define (fetch) the-head)))))
> 
> the-head depends on (car the-pair) and the-pair is a variable passed to
> the macro. So I would expect this to create different identifiers for
> different values of the-pair, just like it creates different identifiers
> when instead of (car the-pair) I use fetch (also passed from outside).


You're right, that's confusing.

I don't have the time to investigate, though.



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