mirror of https://github.com/gohugoio/hugo
79 lines
2.0 KiB
Go
79 lines
2.0 KiB
Go
// Copyright 2024 The Hugo Authors. 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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// 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 predicate
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// P is a predicate function that tests whether a value of type T satisfies some condition.
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type P[T any] func(T) bool
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// And returns a predicate that is a short-circuiting logical AND of this and the given predicates.
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func (p P[T]) And(ps ...P[T]) P[T] {
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return func(v T) bool {
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for _, pp := range ps {
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if !pp(v) {
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return false
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}
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}
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if p == nil {
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return true
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}
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return p(v)
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}
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}
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// Or returns a predicate that is a short-circuiting logical OR of this and the given predicates.
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func (p P[T]) Or(ps ...P[T]) P[T] {
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return func(v T) bool {
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for _, pp := range ps {
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if pp(v) {
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return true
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}
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}
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if p == nil {
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return false
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}
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return p(v)
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}
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}
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// Negate returns a predicate that is a logical negation of this predicate.
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func (p P[T]) Negate() P[T] {
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return func(v T) bool {
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return !p(v)
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}
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}
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// Filter returns a new slice holding only the elements of s that satisfy p.
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// Filter modifies the contents of the slice s and returns the modified slice, which may have a smaller length.
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func (p P[T]) Filter(s []T) []T {
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var n int
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for _, v := range s {
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if p(v) {
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s[n] = v
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n++
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}
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}
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return s[:n]
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}
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// FilterCopy returns a new slice holding only the elements of s that satisfy p.
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func (p P[T]) FilterCopy(s []T) []T {
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var result []T
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for _, v := range s {
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if p(v) {
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result = append(result, v)
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}
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}
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return result
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}
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