Created
September 18, 2012 12:16
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Z-combinator (varargs version)
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(defun z (f) | |
((lambda (x) | |
(funcall f (lambda (&rest args) | |
(apply (funcall x x) args) ))) | |
(lambda (x) | |
(funcall f (lambda (&rest args) | |
(apply (funcall x x) args) ))))) | |
(defvar fact | |
(lambda (f) | |
(lambda (x) | |
(if (zerop x) 1 (* x (funcall f (1- x)))) ))) | |
(defvar make-2-tuples | |
(lambda (f) | |
(lambda (l1 l2) | |
(when (and l1 l2) | |
(cons (cons (car l1) (car l2)) | |
(funcall f (cdr l1) (cdr l2)) ))))) | |
(defvar make-n-tuples | |
(lambda (f) | |
(lambda (&rest lists) | |
(when (every #'identity lists) | |
(cons (mapcar #'car lists) | |
(apply f (mapcar #'cdr lists)) ))))) | |
(print (funcall (z fact) 32)) | |
(print (funcall (z make-2-tuples) '(a b c) '(1 2 3))) | |
(print (funcall (z make-n-tuples) '(a b c) '(1 2 3) '(i j k))) | |
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