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hugo/identity/question.go

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Go

// Copyright 2024 The Hugo Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package identity
import "sync"
// NewQuestion creates a new question with the given identity.
func NewQuestion[T any](id Identity) *Question[T] {
return &Question[T]{
Identity: id,
}
}
// Answer takes a func that knows the answer.
// Note that this is a one-time operation,
// fn will not be invoked again it the question is already answered.
// Use Result to check if the question is answered.
func (q *Question[T]) Answer(fn func() T) {
q.mu.Lock()
defer q.mu.Unlock()
if q.answered {
return
}
q.fasit = fn()
q.answered = true
}
// Result returns the fasit of the question (if answered),
// and a bool indicating if the question has been answered.
func (q *Question[T]) Result() (any, bool) {
q.mu.RLock()
defer q.mu.RUnlock()
return q.fasit, q.answered
}
// A Question is defined by its Identity and can be answered once.
type Question[T any] struct {
Identity
fasit T
mu sync.RWMutex
answered bool
}