branch: externals/dash
commit 79567ad52f6b02c908185c0c0f992a7c7287ff3f
Author: Basil L. Contovounesios <ba...@contovou.net>
Commit: Basil L. Contovounesios <ba...@contovou.net>
Use Emacs 29 'take' and Emacs 30 'sort'
* dash.el (dash--take): New function wrapping 'take'.
(-take, -drop-last): Use it for a speedup or less garbage on some
inputs.
(-sort): Prefer Emacs 30 'sort' calling convention when available.
---
dash.el | 26 +++++++++++++++++++++-----
1 file changed, 21 insertions(+), 5 deletions(-)
diff --git a/dash.el b/dash.el
index 5e1cbc6979..ea70a72dca 100644
--- a/dash.el
+++ b/dash.el
@@ -1246,6 +1246,17 @@ For another variant, see also `-take-while'."
(declare (important-return-value t))
(--drop-while (funcall pred it) list))
+;; Added in Emacs 29.
+(static-if (fboundp 'take)
+ (defun dash--take (n list)
+ "Return the first N elements of LIST.
+Like `take', but ensure result is fresh."
+ (let ((prefix (take n list)))
+ (if (eq prefix list)
+ ;; If same list is returned, make a copy.
+ (copy-sequence prefix)
+ prefix))))
+
(defun -take (n list)
"Return a copy of the first N items in LIST.
Return a copy of LIST if it contains N items or fewer.
@@ -1253,7 +1264,9 @@ Return nil if N is zero or less.
See also: `-take-last'."
(declare (side-effect-free t))
- (--take-while (< it-index n) list))
+ (static-if (fboundp 'dash--take)
+ (dash--take n list)
+ (--take-while (< it-index n) list)))
(defun -take-last (n list)
"Return a copy of the last N items of LIST in order.
@@ -1279,7 +1292,9 @@ Return nil if LIST contains N items or fewer.
See also: `-drop'."
(declare (side-effect-free t))
- (nbutlast (copy-sequence list) n))
+ (static-if (fboundp 'dash--take)
+ (dash--take (- (length list) n) list)
+ (nbutlast (copy-sequence list) n)))
(defun -split-at (n list)
"Split LIST into two sublists after the Nth element.
@@ -3301,9 +3316,10 @@ Return the sorted list. LIST is NOT modified by side
effects.
COMPARATOR is called with two elements of LIST, and should return non-nil
if the first element should sort before the second."
(declare (important-return-value t))
- ;; Not yet worth changing to (sort list :lessp comparator);
- ;; still seems as fast or slightly faster.
- (sort (copy-sequence list) comparator))
+ (static-if (condition-case nil (sort []) (wrong-number-of-arguments))
+ ;; Since Emacs 30.
+ (sort list :lessp comparator)
+ (sort (copy-sequence list) comparator)))
(defmacro --sort (form list)
"Anaphoric form of `-sort'."
