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/*******************************************************************************
* Copyright 2025 Stefan Majewsky <majewsky@gmx.net>
* SPDX-License-Identifier: Apache-2.0
* Refer to the file "LICENSE" for details.
*******************************************************************************/
// Package options provides additional functions for type option.Option
// that cannot be expressed as methods on the Option type itself.
package options
import (
"cmp"
. "github.com/majewsky/gg/option"
)
// NOTE: Keep functions sorted by name.
// FromPointer converts a *T into an Option[T].
func FromPointer[T any](value *T) Option[T] {
if value == nil {
return None[T]()
} else {
return Some(*value)
}
}
// IsNoneOrZero returns whether o is either empty, or contains a zero value.
func IsNoneOrZero[T comparable](o Option[T]) bool {
return o.IsNoneOr(func(value T) bool {
var zero T
return zero == value
})
}
// Map applies the given function to the value contained in o, if there is one.
func Map[T, U any](o Option[T], mapping func(T) U) Option[U] {
if t, ok := o.Unpack(); ok {
return Some(mapping(t))
} else {
return None[U]()
}
}
// Max returns the largest of its input values, while disregarding None values.
// If there are no Some values, None is returned.
func Max[T cmp.Ordered](inputs ...Option[T]) Option[T] {
var (
result T
isSome = false
)
for _, i := range inputs {
value, ok := i.Unpack()
if ok && (!isSome || result < value) {
result = value
isSome = true
}
}
if isSome {
return Some(result)
} else {
return None[T]()
}
}
// Min returns the smallest of its input values, while disregarding None values.
// If there are no Some values, None is returned.
func Min[T cmp.Ordered](inputs ...Option[T]) Option[T] {
var (
result T
isSome = false
)
for _, i := range inputs {
value, ok := i.Unpack()
if ok && (!isSome || result > value) {
result = value
isSome = true
}
}
if isSome {
return Some(result)
} else {
return None[T]()
}
}
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