mirror of
https://github.com/IBM/fp-go.git
synced 2025-08-10 22:31:32 +02:00
60 lines
1.7 KiB
Go
60 lines
1.7 KiB
Go
// Copyright (c) 2023 IBM Corp.
|
|
// 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 constant
|
|
|
|
import (
|
|
F "github.com/IBM/fp-go/function"
|
|
M "github.com/IBM/fp-go/monoid"
|
|
S "github.com/IBM/fp-go/semigroup"
|
|
)
|
|
|
|
type Const[E, A any] struct {
|
|
value E
|
|
}
|
|
|
|
func Make[E, A any](e E) Const[E, A] {
|
|
return Const[E, A]{value: e}
|
|
}
|
|
|
|
func Unwrap[E, A any](c Const[E, A]) E {
|
|
return c.value
|
|
}
|
|
|
|
func Of[E, A any](m M.Monoid[E]) func(A) Const[E, A] {
|
|
return F.Constant1[A](Make[E, A](m.Empty()))
|
|
}
|
|
|
|
func MonadMap[E, A, B any](fa Const[E, A], _ func(A) B) Const[E, B] {
|
|
return Make[E, B](fa.value)
|
|
}
|
|
|
|
func MonadAp[E, A, B any](s S.Semigroup[E]) func(fab Const[E, func(A) B], fa Const[E, A]) Const[E, B] {
|
|
return func(fab Const[E, func(A) B], fa Const[E, A]) Const[E, B] {
|
|
return Make[E, B](s.Concat(fab.value, fa.value))
|
|
}
|
|
}
|
|
|
|
func Map[E, A, B any](f func(A) B) func(fa Const[E, A]) Const[E, B] {
|
|
return F.Bind2nd(MonadMap[E, A, B], f)
|
|
}
|
|
|
|
func Ap[E, A, B any](s S.Semigroup[E]) func(fa Const[E, A]) func(fab Const[E, func(A) B]) Const[E, B] {
|
|
monadap := MonadAp[E, A, B](s)
|
|
return func(fa Const[E, A]) func(fab Const[E, func(A) B]) Const[E, B] {
|
|
return F.Bind2nd(monadap, fa)
|
|
}
|
|
}
|