fp-go/v2/di/utils.go

// Copyright (c) 2023 - 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 di

import (
	DIE "github.com/IBM/fp-go/v2/di/erasure"
	E "github.com/IBM/fp-go/v2/either"
	"github.com/IBM/fp-go/v2/errors"
	F "github.com/IBM/fp-go/v2/function"
	IOE "github.com/IBM/fp-go/v2/ioeither"
	IOO "github.com/IBM/fp-go/v2/iooption"
	O "github.com/IBM/fp-go/v2/option"
)

var (
	toOptionAny   = toType[O.Option[any]]()
	toIOEitherAny = toType[IOE.IOEither[error, any]]()
	toIOOptionAny = toType[IOO.IOOption[any]]()
	toArrayAny    = toType[[]any]()
)

// asDependency converts a generic type to a [DIE.Dependency]
func asDependency[T DIE.Dependency](t T) DIE.Dependency {
	return t
}

// toType converts an any to a T
func toType[T any]() func(t any) E.Either[error, T] {
	return E.ToType[T](errors.OnSome[any]("Value of type [%T] cannot be converted."))
}

// toOptionType converts an any to an Option[any] and then to an Option[T]
func toOptionType[T any](item func(any) E.Either[error, T]) func(t any) E.Either[error, O.Option[T]] {
	return F.Flow2(
		toOptionAny,
		E.Chain(O.Fold(
			F.Nullary2(O.None[T], E.Of[error, O.Option[T]]),
			F.Flow2(
				item,
				E.Map[error](O.Of[T]),
			),
		)),
	)
}

// toIOEitherType converts an any to an IOEither[error, any] and then to an IOEither[error, T]
func toIOEitherType[T any](item func(any) E.Either[error, T]) func(t any) E.Either[error, IOE.IOEither[error, T]] {
	return F.Flow2(
		toIOEitherAny,
		E.Map[error](IOE.ChainEitherK(item)),
	)
}

// toIOOptionType converts an any to an IOOption[any] and then to an IOOption[T]
func toIOOptionType[T any](item func(any) E.Either[error, T]) func(t any) E.Either[error, IOO.IOOption[T]] {
	return F.Flow2(
		toIOOptionAny,
		E.Map[error](IOO.ChainOptionK(F.Flow2(
			item,
			E.ToOption[error, T],
		))),
	)
}

// toArrayType converts an any to a []T
func toArrayType[T any](item func(any) E.Either[error, T]) func(t any) E.Either[error, []T] {
	return F.Flow2(
		toArrayAny,
		E.Chain(E.TraverseArray(item)),
	)
}