[R6RS] Internal DEFINE vs. macros
Fri Apr 15 11:02:17 EDT 2005
dyb at cs.indiana.edu writes:
>> > (let-syntax ((foo (syntax-rules ()
>> > ((foo ?x) (define ?x 'outer)))))
>> > (let ()
>> > (define-syntax foo
>> > (syntax-rules ()
>> > ((foo) (define ?x 'inner))))
>> > (foo a)
>> > a))
>> >> produces outer on PLT, but on Chez says:
>> >> Error: invalid syntax (foo a).
>> >> Why? (If you think I should wait until the full description of
>> >> SYNTAX-CASE is out let me know.)
>> > Chez Scheme processes body forms from left to right and adds macro
>> > definitions to the compile-time environment as it proceeds. [...]
>> I'm probably being dense---why doesn't the definition of FOO get
>> applied to the use then? Why is this an error?
> Yes, you are being dense ;-). The inner foo's pattern matches (foo),
> i.e., zero subforms, and the macro call is (foo a), with one subform.
Good thing I have an R6RS editor at my disposal to proofread my code!
(That's usually Matthew's job. :-) ) Thanks!
Cheers =8-} Mike
Friede, V?lkerverst?ndigung und ?berhaupt blabla
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