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35 lines
967 B
Go
35 lines
967 B
Go
// Copyright (c) 2023 IBM Corp.
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// All rights reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package lazy
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import "sync"
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// Memoize computes the value of the provided IO monad lazily but exactly once
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func Memoize[GA ~func() A, A any](ma GA) GA {
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// synchronization primitives
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var once sync.Once
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var result A
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// callback
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gen := func() {
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result = ma()
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}
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// returns our memoized wrapper
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return func() A {
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once.Do(gen)
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return result
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}
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}
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