mirror/guile
mirror/guile
1
Fork 0
mirror of https://git.savannah.gnu.org/git/guile.git synced 2025-04-29 19:30:36 +02:00
Code Activity

doc: Recommend alist-copy instead of list-copy.

Browse source 
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'.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>
This commit is contained in:
Tomas Volf 2024-05-19 00:47:07 +02:00 • committed by Ludovic Courtès
parent a0368a6120
commit 1c093d8bc4
No known key found for this signature in database
GPG key ID: 090B11993D9AEBB5
1 changed files with 1 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

2
doc/ref/api-data.texi
View file

@ -9510,7 +9510,7 @@ 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.
@rnindex acons