Raymond Toy pushed to branch master at cmucl / cmucl

Commits: 55c01f44 by Raymond Toy at 2023-08-17T13:33:59+00:00 Address #240: Speed up intersection by using a hashtable

- - - - - 14d847f0 by Raymond Toy at 2023-08-17T13:34:15+00:00 Merge branch 'issue-240-intersection-with-hash-table' into 'master'

Address #240: Speed up intersection by using a hashtable

Closes #240

See merge request cmucl/cmucl!160 - - - - -

1 changed file:

- src/code/list.lisp

Changes:

===================================== src/code/list.lisp ===================================== @@ -825,11 +825,20 @@ (declare (inline member)) (if (and testp notp) (error "Test and test-not both supplied.")) - (let ((res nil)) - (dolist (elt list1) - (if (with-set-keys (member (apply-key key elt) list2)) - (push elt res))) - res)) + (let ((hashtable + (list-to-hashtable list2 key test test-not))) + (cond (hashtable + (let ((res nil)) + (dolist (item list1) + (when (nth-value 1 (gethash (apply-key key item) hashtable)) + (push item res))) + res)) + ((null hashtable) + (let ((res nil)) + (dolist (elt list1) + (if (with-set-keys (member (apply-key key elt) list2)) + (push elt res))) + res)))))

(defun nintersection (list1 list2 &key key (test #'eql testp) (test-not nil notp))

View it on GitLab: https://gitlab.common-lisp.net/cmucl/cmucl/-/compare/9d593e3aa3831a687e7d729...