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60 lines
1.8 KiB
Go
60 lines
1.8 KiB
Go
// Copyright (c) 2024 - 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 option
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import (
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"github.com/IBM/fp-go/v2/internal/monad"
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)
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type optionMonad[A, B any] struct{}
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func (o *optionMonad[A, B]) Of(a A) Option[A] {
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return Of[A](a)
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}
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func (o *optionMonad[A, B]) Map(f func(A) B) Operator[A, B] {
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return Map[A, B](f)
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}
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func (o *optionMonad[A, B]) Chain(f Kleisli[A, B]) Operator[A, B] {
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return Chain[A, B](f)
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}
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func (o *optionMonad[A, B]) Ap(fa Option[A]) func(Option[func(A) B]) Option[B] {
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return Ap[B, A](fa)
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}
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// Monad implements the monadic operations for Option.
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// A monad provides a way to chain computations that may fail, handling the
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// None case automatically.
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//
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// The monad interface includes:
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// - Of: wraps a value in an Option
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// - Map: transforms the contained value
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// - Chain: sequences Option-returning operations
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// - Ap: applies an Option-wrapped function to an Option-wrapped value
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//
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// Example:
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//
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// m := Monad[int, string]()
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// result := m.Chain(func(x int) Option[string] {
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// if x > 0 { return Some(fmt.Sprintf("%d", x)) }
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// return None[string]()
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// })(Some(42)) // Some("42")
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func Monad[A, B any]() monad.Monad[A, B, Option[A], Option[B], Option[func(A) B]] {
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return &optionMonad[A, B]{}
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}
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