forked from mirrors/gecko-dev
bc5984bc55
MozReview-Commit-ID: G8f9iSL43Jw --HG-- extra : rebase_source : 391ea220595c4b17f279e3f00538268641a7eae0 extra : amend_source : a3852f238df4cb618a42e7d102faec1ddac6f697
14 lines
529 B
JavaScript
14 lines
529 B
JavaScript
/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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// The Y combinator, applied to the factorial function.
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// Return the function that is the fixed point of f.
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const Y = f => (x => f(v => x(x)(v)))
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(x => f(v => x(x)(v)));
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// The factorial function is the fixed point of this:
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const f = fac => n => (n <= 1) ? 1 : n * fac(n - 1);
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print(`5! is ${Y(f)(5)}`);
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