mirror of
https://github.com/IBM/fp-go.git
synced 2025-06-23 00:27:49 +02:00
41 lines
1.3 KiB
Go
41 lines
1.3 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 either
|
|
|
|
import (
|
|
EQ "github.com/IBM/fp-go/eq"
|
|
F "github.com/IBM/fp-go/function"
|
|
)
|
|
|
|
// Constructs an equal predicate for an `Either`
|
|
func Eq[E, A any](e EQ.Eq[E], a EQ.Eq[A]) EQ.Eq[Either[E, A]] {
|
|
// some convenient shortcuts
|
|
eqa := F.Curry2(a.Equals)
|
|
eqe := F.Curry2(e.Equals)
|
|
|
|
fca := F.Bind2nd(Fold[E, A, bool], F.Constant1[A](false))
|
|
fce := F.Bind1st(Fold[E, A, bool], F.Constant1[E](false))
|
|
|
|
fld := Fold(F.Flow2(eqe, fca), F.Flow2(eqa, fce))
|
|
|
|
return EQ.FromEquals(F.Uncurry2(fld))
|
|
}
|
|
|
|
// FromStrictEquals constructs an `Eq` from the canonical comparison function
|
|
func FromStrictEquals[E, A comparable]() EQ.Eq[Either[E, A]] {
|
|
return Eq(EQ.FromStrictEquals[E](), EQ.FromStrictEquals[A]())
|
|
}
|