Created
June 1, 2021 09:50
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| (defun same (key-fn list &key (test #'eql)) | |
| "True if KEY-FN returns the same value for every element of LIST. | |
| Example: (same #'length '((a b c) (d e f) #(1 2 3))) => T" | |
| (or (null list) | |
| (loop with v = (funcall key-fn (first list)) | |
| for x in (rest list) | |
| always (funcall test v (funcall key-fn x))))) |
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