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[bug#60225] [PATCH] records: match-record supports specifying a differen
From: |
Attila Lendvai |
Subject: |
[bug#60225] [PATCH] records: match-record supports specifying a different variable name. |
Date: |
Tue, 20 Dec 2022 14:40:19 -0300 |
An example:
(match-record obj <my-type>
(field1 (field2 custom-var-name) field3)
...)
---
guix/records.scm | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/guix/records.scm b/guix/records.scm
index 13463647c8..0b2487a156 100644
--- a/guix/records.scm
+++ b/guix/records.scm
@@ -592,13 +592,16 @@ (define-syntax lookup-field
(define-syntax match-record-inner
(lambda (s)
(syntax-case s ()
- ((_ record type (field rest ...) body ...)
- #`(let-syntax ((field-offset (syntax-rules ()
+ ((_ record type ((field-name variable-name) rest ...) body ...)
+ #'(let-syntax ((field-offset (syntax-rules ()
((_ f)
- (lookup-field field 0 f)))))
+ (lookup-field field-name 0 f)))))
(let* ((offset (type map-fields field-offset))
- (field (struct-ref record offset)))
+ (variable-name (struct-ref record offset)))
(match-record-inner record type (rest ...) body ...))))
+ ((_ record type (field rest ...) body ...)
+ ;; Redirect to the canonical form above.
+ #'(match-record-inner record type ((field field) rest ...) body ...))
((_ record type () body ...)
#'(begin body ...)))))
--
2.35.1
- [bug#60225] [PATCH] records: match-record supports specifying a different variable name.,
Attila Lendvai <=