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https://github.com/IBM/fp-go.git
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7d3759619c
* fix: implement bind, let, apS for serveral monads Signed-off-by: Dr. Carsten Leue <carsten.leue@de.ibm.com> * fix: implement bind for maps Signed-off-by: Dr. Carsten Leue <carsten.leue@de.ibm.com> * fix: implement do notation for more monads Signed-off-by: Dr. Carsten Leue <carsten.leue@de.ibm.com> * fix: add bind to more monads Signed-off-by: Dr. Carsten Leue <carsten.leue@de.ibm.com> * fix: add Do and Bind support to Monads Signed-off-by: Dr. Carsten Leue <carsten.leue@de.ibm.com> --------- Signed-off-by: Dr. Carsten Leue <carsten.leue@de.ibm.com>
109 lines
3.1 KiB
Go
109 lines
3.1 KiB
Go
// Copyright (c) 2023 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 optiont
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import (
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F "github.com/IBM/fp-go/function"
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"github.com/IBM/fp-go/internal/apply"
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FC "github.com/IBM/fp-go/internal/functor"
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O "github.com/IBM/fp-go/option"
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)
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func Of[A, HKTA any](fof func(O.Option[A]) HKTA, a A) HKTA {
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return F.Pipe2(a, O.Of[A], fof)
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}
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func None[A, HKTA any](fof func(O.Option[A]) HKTA) HKTA {
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return F.Pipe1(O.None[A](), fof)
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}
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func OfF[A, HKTA, HKTEA any](fmap func(HKTA, func(A) O.Option[A]) HKTEA, fa HKTA) HKTEA {
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return fmap(fa, O.Of[A])
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}
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func MonadMap[A, B, HKTFA, HKTFB any](fmap func(HKTFA, func(O.Option[A]) O.Option[B]) HKTFB, fa HKTFA, f func(A) B) HKTFB {
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// HKTGA = Either[E, A]
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// HKTGB = Either[E, B]
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return FC.MonadMap(fmap, O.MonadMap[A, B], fa, f)
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}
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func MonadChain[A, B, HKTFA, HKTFB any](
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fchain func(HKTFA, func(O.Option[A]) HKTFB) HKTFB,
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fof func(O.Option[B]) HKTFB,
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ma HKTFA,
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f func(A) HKTFB) HKTFB {
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// dispatch to the even more generic implementation
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return fchain(ma, O.Fold(F.Nullary2(O.None[B], fof), f))
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}
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func Chain[A, B, HKTFA, HKTFB any](
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fchain func(HKTFA, func(O.Option[A]) HKTFB) HKTFB,
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fof func(O.Option[B]) HKTFB,
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f func(A) HKTFB) func(ma HKTFA) HKTFB {
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// dispatch to the even more generic implementation
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return func(ma HKTFA) HKTFB {
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return MonadChain(fchain, fof, ma, f)
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}
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}
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func MonadAp[A, B, HKTFAB, HKTFGAB, HKTFA, HKTFB any](
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fap func(HKTFGAB, HKTFA) HKTFB,
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fmap func(HKTFAB, func(O.Option[func(A) B]) func(O.Option[A]) O.Option[B]) HKTFGAB,
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fab HKTFAB,
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fa HKTFA) HKTFB {
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return apply.MonadAp(fap, fmap, O.MonadAp[B, A], fab, fa)
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}
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func MatchE[A, HKTEA, HKTB any](mchain func(HKTEA, func(O.Option[A]) HKTB) HKTB, onNone func() HKTB, onSome func(A) HKTB) func(HKTEA) HKTB {
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return F.Bind2nd(mchain, O.Fold(onNone, onSome))
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}
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func FromOptionK[A, B, HKTB any](
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fof func(O.Option[B]) HKTB,
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f func(A) O.Option[B]) func(A) HKTB {
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return F.Flow2(f, fof)
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}
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func MonadChainOptionK[A, B, HKTA, HKTB any](
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fchain func(HKTA, func(O.Option[A]) HKTB) HKTB,
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fof func(O.Option[B]) HKTB,
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ma HKTA,
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f func(A) O.Option[B],
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) HKTB {
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return MonadChain(fchain, fof, ma, FromOptionK(fof, f))
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}
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func MonadAlt[LAZY ~func() HKTFA, A, HKTFA any](
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fof func(O.Option[A]) HKTFA,
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fchain func(HKTFA, func(O.Option[A]) HKTFA) HKTFA,
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first HKTFA,
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second LAZY) HKTFA {
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return fchain(first, O.Fold(second, F.Flow2(O.Of[A], fof)))
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}
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func Alt[LAZY ~func() HKTFA, A, HKTFA any](
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fof func(O.Option[A]) HKTFA,
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fchain func(HKTFA, func(O.Option[A]) HKTFA) HKTFA,
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second LAZY) func(HKTFA) HKTFA {
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return func(fa HKTFA) HKTFA {
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return MonadAlt(fof, fchain, fa, second)
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}
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}
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