Subject: Re: bug#67255: define-library does not support 'rename' directives

From: Timothy Sample <[email-masked]>
Date: Mon, 20 Nov 2023 11:14:20 -0600

Timothy Sample <[email-masked]> writes:

> Maxim Cournoyer <[email-masked]> writes:
>
>> Our R7RS define-library syntax, from (ice-9 r7rs-library) does not
>> support renaming bindings to export, via 'rename' directives.
>
> I appreciate your R7RS debugging effort.  Thanks!

Actions speak louder than words, so here’s a patch!

The ‘define-library’ syntax uses the R6RS ‘library’ syntax under the
hood.  TIL that R6RS and R7RS have different syntax for 'rename'.  In
R6RS, you write:

    (export (rename (internal external)))

while in R7RS, it’s:

    (export (rename internal external))

My patch adds a conversion step to deal with this difference.

>From b87bf8910ac8e75dc0ec63cb7385ddf199fd400c Mon Sep 17 00:00:00 2001
From: Timothy Sample <[email-masked]>
Date: Mon, 20 Nov 2023 11:01:08 -0600
Subject: [PATCH] Use R7RS 'rename' syntax for exports.

Fixes <https://bugs.gnu.org/67255>.
Reported by Maxim Cournoyer <[email-masked]>.

* module/ice-9/r7rs-libraries.scm (define-library): Convert R7RS
exports to R6RS exports before passing them on to 'library'.
---
 module/ice-9/r7rs-libraries.scm | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/module/ice-9/r7rs-libraries.scm b/module/ice-9/r7rs-libraries.scm
index 63a300a26..f8b6b4c59 100644
--- a/module/ice-9/r7rs-libraries.scm
+++ b/module/ice-9/r7rs-libraries.scm
@@ -1,5 +1,5 @@
 ;; R7RS library support
-;;      Copyright (C) 2020, 2021 Free Software Foundation, Inc.
+;;      Copyright (C) 2020, 2021, 2023 Free Software Foundation, Inc.
 ;;
 ;; This library is free software; you can redistribute it and/or
 ;; modify it under the terms of the GNU Lesser General Public
@@ -97,12 +97,17 @@
            ((decl ...)
             (partition-decls #'(decl ... . decls) exports imports code))))))
 
+    (define (r7rs-export->r6rs-export export)
+      (syntax-case export (rename)
+        ((rename internal external) #'(rename (internal external)))
+        (_ export)))
+
     (syntax-case stx ()
       ((_ name decl ...)
        (call-with-values (lambda ()
                            (partition-decls #'(decl ...) '() '() '()))
          (lambda (exports imports code)
            #`(library name
-               (export . #,exports)
+               (export . #,(map r7rs-export->r6rs-export exports))
                (import . #,imports)
                . #,code)))))))
-- 
2.41.0