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71 lines
2.6 KiB
Go
71 lines
2.6 KiB
Go
// Copyright (c) 2023 - 2025 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 readerresult
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import (
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G "github.com/IBM/fp-go/v2/readereither/generic"
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)
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// TraverseArray applies a ReaderResult-returning function to each element of an array,
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// collecting the results. If any element fails, the entire operation fails with the first error.
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//
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// Example:
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//
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// parseUser := func(id int) readerresult.ReaderResult[DB, User] { ... }
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// ids := []int{1, 2, 3}
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// result := readerresult.TraverseArray[DB](parseUser)(ids)
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// // result(db) returns result.Result[[]User] with all users or first error
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//
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//go:inline
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func TraverseArray[L, A, B any](f Kleisli[L, A, B]) Kleisli[L, []A, []B] {
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return G.TraverseArray[ReaderResult[L, B], ReaderResult[L, []B], []A](f)
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}
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// TraverseArrayWithIndex is like TraverseArray but the function also receives the element's index.
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// This is useful when the transformation depends on the position in the array.
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//
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// Example:
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//
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// processItem := func(idx int, item string) readerresult.ReaderResult[Config, int] {
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// return readerresult.Of[Config](idx + len(item))
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// }
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// items := []string{"a", "bb", "ccc"}
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// result := readerresult.TraverseArrayWithIndex[Config](processItem)(items)
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//
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//go:inline
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func TraverseArrayWithIndex[L, A, B any](f func(int, A) ReaderResult[L, B]) Kleisli[L, []A, []B] {
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return G.TraverseArrayWithIndex[ReaderResult[L, B], ReaderResult[L, []B], []A](f)
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}
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// SequenceArray converts an array of ReaderResult values into a single ReaderResult of an array.
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// If any element fails, the entire operation fails with the first error encountered.
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// All computations share the same environment.
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//
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// Example:
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//
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// readers := []readerresult.ReaderResult[Config, int]{
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// readerresult.Of[Config](1),
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// readerresult.Of[Config](2),
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// readerresult.Of[Config](3),
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// }
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// result := readerresult.SequenceArray(readers)
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// // result(cfg) returns result.Of([]int{1, 2, 3})
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//
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//go:inline
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func SequenceArray[L, A any](ma []ReaderResult[L, A]) ReaderResult[L, []A] {
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return G.SequenceArray[ReaderResult[L, A], ReaderResult[L, []A]](ma)
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}
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