gonads/option.go

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package gonads
import "errors"
var (
ErrOptionIsNone = errors.New("gonads: Option[T] has no value")
)
// Option is a container that might contain a value.
type Option[T any] struct {
val *T
}
// IsSome returns true if the Option has some value in it.
func (o Option[T]) IsSome() bool {
return o.val != nil
}
// IsNone returns true if the Option has no value in it.
func (o Option[T]) IsNone() bool {
return !o.IsSome()
}
// Yank will pull a value out of an option, panicking if it doesn't exist.
func (o Option[T]) Yank() T {
if o.IsNone() {
panic("gonads: Yank on None Option")
}
return *o.val
}
// Take a value out of the option if it exists.
func (o Option[T]) Take() (T, error) {
if o.IsNone() {
var zero T
return zero, ErrOptionIsNone
}
return *o.val, nil
}
// Set the value of the option to a given value.
func (o *Option[T]) Set(val T) {
o.val = &val
}
// Clear removes the value from an Option.
func (o *Option[T]) Clear() {
o.val = nil
}
// NewOption creates a new Option with the given type. All Options
// Start out as nil.
func NewOption[T any]() *Option[T] {
return &Option[T]{}
}