mirror of
https://github.com/IBM/fp-go.git
synced 2025-11-23 22:14:53 +02:00
70 lines
2.0 KiB
Go
70 lines
2.0 KiB
Go
// Copyright (c) 2025 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 option
|
|
|
|
import (
|
|
"log"
|
|
|
|
F "github.com/IBM/fp-go/v2/function"
|
|
L "github.com/IBM/fp-go/v2/logging"
|
|
)
|
|
|
|
func _log[A any](left func(string, ...any), right func(string, ...any), prefix string) Kleisli[Option[A], A] {
|
|
return Fold(
|
|
func() Option[A] {
|
|
left("%s", prefix)
|
|
return None[A]()
|
|
},
|
|
func(a A) Option[A] {
|
|
right("%s: %v", prefix, a)
|
|
return Some(a)
|
|
})
|
|
}
|
|
|
|
// Logger creates a logging function for Options that logs the state (None or Some with value)
|
|
// and returns the original Option unchanged. This is useful for debugging pipelines.
|
|
//
|
|
// Parameters:
|
|
// - loggers: optional log.Logger instances to use for logging (defaults to standard logger)
|
|
//
|
|
// Returns a function that takes a prefix string and returns a function that logs and passes through an Option.
|
|
//
|
|
// Example:
|
|
//
|
|
// logger := Logger[int]()
|
|
// result := F.Pipe2(
|
|
// Some(42),
|
|
// logger("step1"), // logs "step1: 42"
|
|
// Map(func(x int) int { return x * 2 }),
|
|
// ) // Some(84)
|
|
//
|
|
// result := F.Pipe1(
|
|
// None[int](),
|
|
// logger("step1"), // logs "step1"
|
|
// ) // None
|
|
func Logger[A any](loggers ...*log.Logger) func(string) Kleisli[Option[A], A] {
|
|
left, right := L.LoggingCallbacks(loggers...)
|
|
return func(prefix string) Kleisli[Option[A], A] {
|
|
delegate := _log[A](left, right, prefix)
|
|
return func(ma Option[A]) Option[A] {
|
|
return F.Pipe1(
|
|
delegate(ma),
|
|
ChainTo[A](ma),
|
|
)
|
|
}
|
|
}
|
|
}
|