Add variants

[bkiac]

Unfortunately, this is necessary to nicely display methods on a Result object:

export interface SomeVariant<T> {
	readonly some: true
	readonly none: false
	readonly value: T
}

export interface NoneVariant {
	readonly some: false
	readonly none: true
}

export type OptionVariants<T> = SomeVariant<T> | NoneVariant

export type Option<T> = OptionVariants<T> & OptionMethods<T>

See this example:

Using variants will force TypeScript to use the function signature defined in the ResultMethods interface.

Although this looks nicer on the Result type:

type Result<T, E> = Ok<T> | Err<E>

This will output a function signature that's the result of the Ok and Err union: