diff options
Diffstat (limited to 'lisp/emacs-lisp/seq.el')
| -rw-r--r-- | lisp/emacs-lisp/seq.el | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/lisp/emacs-lisp/seq.el b/lisp/emacs-lisp/seq.el index 8362ddafd3f..92f0ad78566 100644 --- a/lisp/emacs-lisp/seq.el +++ b/lisp/emacs-lisp/seq.el @@ -4,7 +4,7 @@ ;; Author: Nicolas Petton <nicolas@petton.fr> ;; Keywords: sequences -;; Version: 2.3 +;; Version: 2.14 ;; Package: seq ;; Maintainer: emacs-devel@gnu.org @@ -144,6 +144,18 @@ if positive or too small if negative)." sequence) (nreverse result))) +(defun seq-map-indexed (function sequence) + "Return the result of applying FUNCTION to each element of SEQUENCE. +Unlike `seq-map', FUNCTION takes two arguments: the element of +the sequence, and its index within the sequence." + (let ((index 0)) + (seq-map (lambda (elt) + (prog1 + (funcall function elt index) + (setq index (1+ index)))) + sequence))) + + ;; faster implementation for sequences (sequencep) (cl-defmethod seq-map (function (sequence sequence)) (mapcar function sequence)) @@ -206,6 +218,16 @@ The result is a sequence of the same type as SEQUENCE." (cl-defmethod seq-sort (pred (list list)) (sort (seq-copy list) pred)) +(defun seq-sort-by (function pred sequence) + "Sort SEQUENCE using PRED as a comparison function. +Elements of SEQUENCE are transformed by FUNCTION before being +sorted. FUNCTION must be a function of one argument." + (seq-sort (lambda (a b) + (funcall pred + (funcall function a) + (funcall function b))) + sequence)) + (cl-defgeneric seq-reverse (sequence) "Return a sequence with elements of SEQUENCE in reverse order." (let ((result '())) |