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bug#11988: eval-case redefinition?
From: |
Ludovic Courtès |
Subject: |
bug#11988: eval-case redefinition? |
Date: |
Sat, 06 Oct 2012 23:24:19 +0200 |
User-agent: |
Gnus/5.130005 (Ma Gnus v0.5) Emacs/24.2 (gnu/linux) |
Hi,
Sorry for the delay.
Daniel Llorens <address@hidden> skribis:
> I was cleaning up an old script which goes like this:
>
> (define (eval-case ...) ... val)
>
> (define var (eval-case ...))
>
> This worked from the REPL, but when loading the file with (load
> "script"), var was always #<unspecified>. It turns out that (my)
> eval-case is never executed in this case.
It turns out that ‘eval-case’ is a macro, and it gets macro-expanded in
the RHS of ‘define var’ above.
This is the same situation as:
--8<---------------cut here---------------start------------->8---
(define-syntax-rule (foo x) (- x))
(define (foo x) x)
(pk 'foo (foo 42)) ; prints -42
--8<---------------cut here---------------end--------------->8---
“Expansion process” in R6RS seems to suggest that this is a bug:
For the right-hand side of the definition of a variable, ex-
pansion is deferred until after all of the definitions have
been seen. Consequently, each keyword and variable refer-
ence within the right-hand side resolves to the local bind-
ing, if any.
Hmmm... Thoughts?
Ludo’.
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