branch: externals/dash
commit c6d7342616eff79f11ff205fa9e4b446329fa210
Author: Basil L. Contovounesios <[email protected]>
Commit: Basil L. Contovounesios <[email protected]>
Minor loop optimization
* dash.el (--each, --each-while): Restrict scope of it and it-index
bindings, and prefer let over setq for minor performance gains.
---
dash.el | 25 +++++++++++++++----------
1 file changed, 15 insertions(+), 10 deletions(-)
diff --git a/dash.el b/dash.el
index efc4da665b..0001bda37c 100644
--- a/dash.el
+++ b/dash.el
@@ -68,12 +68,12 @@ This is the anaphoric counterpart to `-each'."
(let ((l (make-symbol "list"))
(i (make-symbol "i")))
`(let ((,l ,list)
- (,i 0)
- it it-index)
- (ignore it it-index)
+ (,i 0))
(while ,l
- (setq it (pop ,l) it-index ,i ,i (1+ ,i))
- ,@body))))
+ (let ((it (pop ,l)) (it-index ,i))
+ (ignore it it-index)
+ ,@body)
+ (setq ,i (1+ ,i))))))
(defun -each (list fn)
"Call FN on each element of LIST.
@@ -110,11 +110,16 @@ This is the anaphoric counterpart to `-each-while'."
(elt (make-symbol "elt")))
`(let ((,l ,list)
(,i 0)
- ,elt it it-index)
- (ignore it it-index)
- (while (and ,l (setq ,elt (car-safe ,l) it ,elt it-index ,i) ,pred)
- (setq it ,elt it-index ,i ,i (1+ ,i) ,l (cdr ,l))
- ,@body))))
+ ,elt)
+ (while (when ,l
+ (setq ,elt (car-safe ,l))
+ (let ((it ,elt) (it-index ,i))
+ (ignore it it-index)
+ ,pred))
+ (let ((it ,elt) (it-index ,i))
+ (ignore it it-index)
+ ,@body)
+ (setq ,i (1+ ,i) ,l (cdr ,l))))))
(defun -each-while (list pred fn)
"Call FN on each ITEM in LIST, while (PRED ITEM) is non-nil.
