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bug#50928: remove-dups
From: |
Tak Kunihiro |
Subject: |
bug#50928: remove-dups |
Date: |
Tue, 05 Oct 2021 12:03:11 +0900 (JST) |
>> Now I can find its existence in (info
>> "(elisp) Sequence Functions"). I wonder how I could have reached to
>> the function by myself.
>>
>> How did you find it? (apropos-documentation "duplicate")?
>
> I just... knew about seq.el. The cross-referencing between the older
> sequence functions and seq.el is rather lacking -- basically all these
> older functions should probably reference something in seq.el in their
> doc strings.
How about something like below?
commit xxx
Author: yyy
Date: zzz
Add references to a newer function `seq-uniq' in seq.el
* lisp/subr.el (delete-dups):
* doc/lispref/lists.texi (Sets And Lists):
* doc/lispref/lists.texi (delete-dups): Refer to `seq-uniq' (bug#50928).
diff --git a/lisp/subr.el b/lisp/subr.el
index e4819c4b2b..228d2e0c22 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -696,7 +696,7 @@ delete-dups
"Destructively remove `equal' duplicates from LIST.
Store the result in LIST and return it. LIST must be a proper list.
Of several `equal' occurrences of an element in LIST, the first
-one is kept."
+one is kept. See `seq-uniq' for non-destructive operation."
(let ((l (length list)))
(if (> l 100)
(let ((hash (make-hash-table :test #'equal :size l))
diff --git a/doc/lispref/lists.texi b/doc/lispref/lists.texi
index 75641256b6..66c556ecd0 100644
--- a/doc/lispref/lists.texi
+++ b/doc/lispref/lists.texi
@@ -1227,13 +1227,13 @@ Sets And Lists
@cindex lists as sets
@cindex sets
- A list can represent an unordered mathematical set---simply consider a
-value an element of a set if it appears in the list, and ignore the
-order of the list. To form the union of two sets, use @code{append} (as
-long as you don't mind having duplicate elements). You can remove
-@code{equal} duplicates using @code{delete-dups}. Other useful
-functions for sets include @code{memq} and @code{delq}, and their
-@code{equal} versions, @code{member} and @code{delete}.
+ A list can represent an unordered mathematical set---simply consider
+a value an element of a set if it appears in the list, and ignore the
+order of the list. To form the union of two sets, use @code{append}
+(as long as you don't mind having duplicate elements). You can remove
+@code{equal} duplicates using @code{delete-dups} or @code{seq-uniq}.
+Other useful functions for sets include @code{memq} and @code{delq},
+and their @code{equal} versions, @code{member} and @code{delete}.
@cindex CL note---lack @code{union}, @code{intersection}
@quotation
@@ -1489,7 +1489,8 @@ Sets And Lists
This function destructively removes all @code{equal} duplicates from
@var{list}, stores the result in @var{list} and returns it. Of
several @code{equal} occurrences of an element in @var{list},
-@code{delete-dups} keeps the first one.
+@code{delete-dups} keeps the first one. See @code{seq-uniq} for
+non-destructive operation.
@end defun
See also the function @code{add-to-list}, in @ref{List Variables},