options.go

package utils

import "reflect"

type Options[T any] struct {
    values T
    none   bool
}

type OptionInterface[T any] interface {
    IsSome() bool
    IsNone() bool
    Unwrap() T
    Expect(msg string) T
    UnwrapOr(defaultValue T) T
    IsSomeAnd(fn func(args ...interface{}) bool) bool
    Inspect() Options[T]
}

func Some[T any](value T) Options[T] {
    return Options[T]{values: value, none: reflect.ValueOf(value).IsZero()}
}

func None[T any]() Options[T] {
    return Options[T]{none: true}
}

func (o Options[T]) IsSome() bool {
    return !o.none
}

func (o Options[T]) IsNone() bool {
    return o.none
}

func (o Options[T]) Unwrap() T {
    if o.none {
        panic("Unwrap: Option is None")
    }
    return o.values
}

func (o Options[T]) Expect(msg string) T {
    if o.none {
        panic("Expect: " + msg)
    }
    return o.values
}

func (o Options[T]) UnwrapOr(defaultValue any) any {
    if o.none {
        return defaultValue
    }
    return o.values
}

func (o Options[T]) IsSomeAnd(fn func(args ...interface{}) bool) bool {
    if o.none {
        return false
    }
    return fn(o.values)
}

func (o Options[T]) Inspect() Options[T] {
    return o
}

func Option[T any](value T) Options[T] {
    if(&value == nil){
        return None[T]()
    }else{
        return Some[T](value)
    }
}