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Use iteration in math-factorial-iter

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* lisp/calc/calc-comb.el (math-factorial-iter):
Use iteration instead of recursion to avoid max-specpdl-size problem.
Copyright-paperwork-exempt: yes
This commit is contained in:
michael schuldt 2017-04-18 11:24:37 -07:00 committed by Paul Eggert
parent 0c98dec5c9
commit d831312d66
1 changed files with 7 additions and 5 deletions
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12
lisp/calc/calc-comb.el
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@ -362,11 +362,13 @@
(math-gammap1-raw '(float -25 -2))))
(defun math-factorial-iter (count n f)
(if (= (% n 5) 1)
(math-working (format "factorial(%d)" (1- n)) f))
(if (> count 0)
(math-factorial-iter (1- count) (1+ n) (math-mul n f))
f))
(while (> count 0)
(if (= (% n 5) 1)
(math-working (format "factorial(%d)" (1- n)) f))
(setq count (1- count)
f (math-mul n f)
n (1+ n)))
f)
(defun calcFunc-dfact (n) ; [I I] [F F] [Public]
(cond ((Math-integer-negp n)