Re: error Wrong type to apply: #<syntax-transformer

[Damien Mattei]

thank you
it is clear now , even if i really never find the macro needed upward
i tested too in racket your example and the messages is simple to understand :

Welcome to DrRacket, version 8.9 [cs].
Language: reader
"../Scheme-PLUS-for-Racket/main/Scheme-PLUS-for-Racket/SRFI/SRFI-105.rkt",
with debugging; memory limit: 8192 MB.
'()
> foo
foo: undefined;
 cannot reference an identifier before its definition
> bar
bar: undefined;
 cannot reference an identifier before its definition
> (define (foo)
  (bar 'quux))
> (define-syntax-rule (bar x) x)
> (display (foo))
. . ../../../../../../../Applications/Racket
v8.9/collects/racket/private/kw.rkt:1263:25: bar: undefined;
 cannot reference an identifier before its definition

On Thu, Aug 3, 2023 at 11:58 AM Jean Abou Samra <jean@abou-samra.fr> wrote:
>
> overload.scm must be before some definitions of scheme-infix.scm even
> if it is not used here, it is strange, i do not understand all but it
> compiles now
>
>
>
> A minimal reproducer for your problem is
>
> (define (foo)
>   (bar 'quux))
> (define-syntax-rule (bar x) x)
> (display (foo))
>
>
> Let's dissect what happens. At macro expansion time (during byte 
> compilation), first the definition of foo is expanded. bar is unbound, so 
> it's compiled as a function call. Then comes the definition of bar as a 
> macro, but foo has already been expanded without it.
>
> At runtime, a macro is bound to a syntax transformer, so the binding for bar 
> that was unresolved at expand time gets resolved to the toplevel binding that 
> gets defined for bar, and you get this error because a macro transformer 
> can't be called as  a function.
>
>