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| author | Stefan Monnier | 2004-03-22 15:17:01 +0000 |
|---|---|---|
| committer | Stefan Monnier | 2004-03-22 15:17:01 +0000 |
| commit | 1de9630d9ba42a033a42a2466924ea98d9ba75b4 (patch) | |
| tree | b25f7a650b778a56b299fda4abd239629f7c8a05 | |
| parent | 35abd1e238ff1dfa240af85e6cd2bb615945d1be (diff) | |
| download | emacs-1de9630d9ba42a033a42a2466924ea98d9ba75b4.tar.gz emacs-1de9630d9ba42a033a42a2466924ea98d9ba75b4.zip | |
(backquote-list*-macro): Use nreverse.
| -rw-r--r-- | lisp/emacs-lisp/backquote.el | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/lisp/emacs-lisp/backquote.el b/lisp/emacs-lisp/backquote.el index 81e1a91f76c..6a2baeb3fe9 100644 --- a/lisp/emacs-lisp/backquote.el +++ b/lisp/emacs-lisp/backquote.el | |||
| @@ -1,6 +1,6 @@ | |||
| 1 | ;;; backquote.el --- implement the ` Lisp construct | 1 | ;;; backquote.el --- implement the ` Lisp construct |
| 2 | 2 | ||
| 3 | ;;; Copyright (C) 1990, 1992, 1994, 2001 Free Software Foundation, Inc. | 3 | ;; Copyright (C) 1990, 92, 1994, 2001, 2004 Free Software Foundation, Inc. |
| 4 | 4 | ||
| 5 | ;; Author: Rick Sladkey <jrs@world.std.com> | 5 | ;; Author: Rick Sladkey <jrs@world.std.com> |
| 6 | ;; Maintainer: FSF | 6 | ;; Maintainer: FSF |
| @@ -44,6 +44,9 @@ | |||
| 44 | "Like `list' but the last argument is the tail of the new list. | 44 | "Like `list' but the last argument is the tail of the new list. |
| 45 | 45 | ||
| 46 | For example (backquote-list* 'a 'b 'c) => (a b . c)" | 46 | For example (backquote-list* 'a 'b 'c) => (a b . c)" |
| 47 | ;; The recursive solution is much nicer: | ||
| 48 | ;; (if list (cons first (apply 'backquote-list*-function list)) first)) | ||
| 49 | ;; but Emacs is not very good at efficiently processing recursion. | ||
| 47 | (if list | 50 | (if list |
| 48 | (let* ((rest list) (newlist (cons first nil)) (last newlist)) | 51 | (let* ((rest list) (newlist (cons first nil)) (last newlist)) |
| 49 | (while (cdr rest) | 52 | (while (cdr rest) |
| @@ -58,7 +61,10 @@ For example (backquote-list* 'a 'b 'c) => (a b . c)" | |||
| 58 | "Like `list' but the last argument is the tail of the new list. | 61 | "Like `list' but the last argument is the tail of the new list. |
| 59 | 62 | ||
| 60 | For example (backquote-list* 'a 'b 'c) => (a b . c)" | 63 | For example (backquote-list* 'a 'b 'c) => (a b . c)" |
| 61 | (setq list (reverse (cons first list)) | 64 | ;; The recursive solution is much nicer: |
| 65 | ;; (if list (list 'cons first (cons 'backquote-list*-macro list)) first)) | ||
| 66 | ;; but Emacs is not very good at efficiently processing such things. | ||
| 67 | (setq list (nreverse (cons first list)) | ||
| 62 | first (car list) | 68 | first (car list) |
| 63 | list (cdr list)) | 69 | list (cdr list)) |
| 64 | (if list | 70 | (if list |