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41 lines
816 B
Go
41 lines
816 B
Go
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// Copyright © 2016 Alan A. A. Donovan & Brian W. Kernighan.
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// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
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// See page 272.
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//!+
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// Package memo provides a concurrency-unsafe
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// memoization of a function of type Func.
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package memo
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// A Memo caches the results of calling a Func.
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type Memo struct {
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f Func
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cache map[string]result
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}
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// Func is the type of the function to memoize.
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type Func func(key string) (interface{}, error)
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type result struct {
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value interface{}
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err error
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}
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func New(f Func) *Memo {
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return &Memo{f: f, cache: make(map[string]result)}
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}
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// NOTE: not concurrency-safe!
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func (memo *Memo) Get(key string) (interface{}, error) {
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res, ok := memo.cache[key]
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if !ok {
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res.value, res.err = memo.f(key)
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memo.cache[key] = res
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}
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return res.value, res.err
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}
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//!-
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