Raymond Toy pushed to branch issue-240-set-diff-with-hash-table at cmucl / cmucl

Commits:

• b100ecd4
  by Raymond Toy at 2023-07-27T17:59:17-07:00

  Compute list length manual instead of calling length
  
  For some strange reason, ansi-test `set-difference.error.11` fails in
  `lisp::list-to-hashtable` which uses `length` to compute the length of
  a list.  Let's try computing the length manually ourselves.
  

1 changed file:

• src/code/list.lisp

Changes:

 	(return-from list-to-hashtable nil))

       ;; If the list is too short, the hashtable makes things

       ;; slower.  We also need to balance memory usage.

-      (let ((len (length list)))

+      (let ((len 0))

+	;; Compute list length ourselves.

+	(dolist (item list)

+	  (declare (ignore item))

+	  (incf len))

 	(when (< len *min-list-length-for-hashtable*)

           (return-from list-to-hashtable nil))

 	(let ((hashtable (make-hash-table :test hash-test :size len)))