diff options
| author | Mattias Engdegård <mattiase@acm.org> | 2022-07-15 21:28:30 +0200 |
|---|---|---|
| committer | Mattias Engdegård <mattiase@acm.org> | 2022-07-16 12:17:32 +0200 |
| commit | eb0e93478e423974fe6c7c7e4d183ea8d9f0e742 (patch) | |
| tree | 872797f73a334fd6e1512d39376833b0197cbc91 /lisp/emacs-lisp | |
| parent | 69223ee97539a73dfd7eef9607e0d3a3911ea93b (diff) | |
| download | emacs-eb0e93478e423974fe6c7c7e4d183ea8d9f0e742.tar.gz emacs-eb0e93478e423974fe6c7c7e4d183ea8d9f0e742.tar.bz2 emacs-eb0e93478e423974fe6c7c7e4d183ea8d9f0e742.zip | |
Transform (list) -> nil in source optimiser
This optimisation is already done in the code generator but performing
it at this earlier stage is a useful normalising step that uncovers
more opportunities.
* lisp/emacs-lisp/byte-opt.el (byte-optimize-list): New.
Diffstat (limited to 'lisp/emacs-lisp')
| -rw-r--r-- | lisp/emacs-lisp/byte-opt.el | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el index a24a5044562..5a138e9fee5 100644 --- a/lisp/emacs-lisp/byte-opt.el +++ b/lisp/emacs-lisp/byte-opt.el @@ -1287,6 +1287,11 @@ See Info node `(elisp) Integer Basics'." `(list ,(nth 1 form)) form)) +(put 'list 'byte-optimizer #'byte-optimize-list) +(defun byte-optimize-list (form) + ;; (list) -> nil + (and (cdr form) form)) + ;; Fixme: delete-char -> delete-region (byte-coded) (put 'set 'byte-optimizer #'byte-optimize-set) |