1
0
mirror of https://github.com/IBM/fp-go.git synced 2025-07-05 00:49:01 +02:00
Files
fp-go/iterator/stateless/generic/compress.go
Dr. Carsten Leue e53e2c53e8 fix: more iterator functions
Signed-off-by: Dr. Carsten Leue <carsten.leue@de.ibm.com>
2023-08-04 17:12:24 +02:00

35 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 generic
import (
F "github.com/IBM/fp-go/function"
O "github.com/IBM/fp-go/option"
T "github.com/IBM/fp-go/tuple"
)
// Compress returns an [Iterator] that filters elements from a data [Iterator] returning only those that have a corresponding element in selector [Iterator] that evaluates to `true`.
// Stops when either the data or selectors iterator has been exhausted.
func Compress[GU ~func() O.Option[T.Tuple2[GU, U]], GB ~func() O.Option[T.Tuple2[GB, bool]], CS ~func() O.Option[T.Tuple2[CS, T.Tuple2[U, bool]]], U any](sel GB) func(GU) GU {
return F.Flow2(
Zip[GU, GB, CS](sel),
FilterMap[GU, CS](F.Flow2(
O.FromPredicate(T.Second[U, bool]),
O.Map(T.First[U, bool]),
)),
)
}