Re: Nested macros

[Lynn Winebarger]

On Friday 30 August 2002 18:11, Wolfgang Jährling wrote:
> I have a problem with nested macros.  The following code illustrates it:
> 
>   (use-modules (ice-9 syncase))
> 
>   (define-syntax inner
>     (syntax-rules ()
>       ((inner FOO)
>        (FOO FOO FOO))))
> 
>   (define-syntax outer
>     (syntax-rules ()
>       ((outer (BAR1 BAR2 BAR3))
>        (list BAR1 BAR2 BAR3))))
> 
>   (outer (inner 'baz))
> 
> I expected the last line to expand into
> 
>   (outer ('baz 'baz 'baz))
> 
> and from that into:
> 
>   (list 'baz 'baz 'baz)
> 
> This does not happen.  The outer macro is expanded first, which results
> in "invalid syntax", as "outer" expects three expressions in the
> perentheses, but there are only two.

      Guile does have problems with macros, but this behaviour is correct.
Macros are always expanded "head first".

> 
> Does anyone have an idea what I could do to reach my goal?

   I'm afraid I can't help you on your actual question.

Lynn