The current recommendation of `list-copy' is not right and does not lead
to preserving the original list:
scheme@(guile-user)> (define x (list (cons 'a 1) (cons 'b 2)))
scheme@(guile-user)> (define y (list-copy x))
scheme@(guile-user)> (assq-set! y 'b 3)
$1 = ((a . 1) (b . 3))
scheme@(guile-user)> x
$2 = ((a . 1) (b . 3))
Correct approach seems to be use `alist-copy' from SRFI-1 leading to the
expected behavior of:
scheme@(guile-user)> ,use (srfi srfi-1)
scheme@(guile-user)> (define x (list (cons 'a 1) (cons 'b 2)))
scheme@(guile-user)> (define y (alist-copy x))
scheme@(guile-user)> (assq-set! y 'b 3)
$1 = ((a . 1) (b . 3))
scheme@(guile-user)> x
$2 = ((a . 1) (b . 2))
* doc/ref/api-data.texi (Adding or Setting Alist Entries): Recommend
`alist-copy'.
---
doc/ref/api-data.texi | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/doc/ref/api-data.texi b/doc/ref/api-data.texi
index 3b9933d97..81552dec3 100644
--- a/doc/ref/api-data.texi
+++ b/doc/ref/api-data.texi
@@ -9509,7 +9509,7 @@ difference to you.
If you need to keep the old value of an association list in a form
independent from the list that results from modification by
@code{acons}, @code{assq-set!}, @code{assv-set!} or @code{assoc-set!},
-use @code{list-copy} to copy the old association list before modifying
+use @code{alist-copy} to copy the old association list before modifying
it.
@deffn {Scheme Procedure} acons key value alist
--
2.41.0
