Outdated egg!
This is an egg for CHICKEN 4, the unsupported old release. You're almost certainly looking for the CHICKEN 5 version of this egg, if it exists.
If it does not exist, there may be equivalent functionality provided by another egg; have a look at the egg index. Otherwise, please consider porting this egg to the current version of CHICKEN.
memoize
TOC »
Description
Memoize is a CHICKEN Scheme egg that provides procedure memoization.
Author
Requirements
Requires srfi-69 egg.
Documentation
- memoize PROC #!optional LIMITprocedure
Memoizes procedure PROC. LIMIT is an integer optionally set to avoid excessive memory usage.
Examples
(use memoize) ;; Factorial - Tail-call optimization version (define (fact x) (let loop ((x x) (acc 1)) (if (= x 0) acc (loop (- x 1) (* x acc))))) (time (fact 10000000)) ; => 3.011s CPU time, 0.071s GC time (major), 16 mutations, 104/27101 GCs (major/minor) (define memo-fact (memoize fact)) ;; First call (time (memo-fact 10000000)) ; => 3.199s CPU time, 0.243s GC time (major), 22 mutations, 223/26982 GCs (major/minor) ;; Second call on... (time (memo-fact 10000000)) ; => 0s CPU time, 10 mutations
Changelog
- 0.1 Initial version
License
Copyright (c) 2013, Arthur Maciel All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. Neither the name of the author nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.