nochoices/src/optional-value.ts

Full featured implementation of options into typescript.

import { Option } from "./option.js"
import { Some } from "./some.js"
import { AreEqual, FlattenOption } from "./types.js";

export abstract class OptionalValue<T> {
  abstract isPresent(): boolean

  abstract isAbsent(): boolean

  abstract unwrap(): T

  abstract map<M>(fn: (a: T) => M): Option<M>

  abstract filter(fn: (a: T) => boolean): Option<T>

  abstract expect(err: Error): T

  abstract unwrapOr<U>(defaultValue: U): T | U

  abstract unwrapOrElse(defaultFn: () => T): T

  abstract flatten(): Option<FlattenOption<T>>

  abstract zip<U>(another: OptionalValue<U>): Option<[T, U]>

  abstract zipWithSome<U>(some: Some<U>): Option<[U, T]>

  abstract and<V>(another: Option<V>): Option<V>

  abstract or(self: Option<T>, another: Option<T>): Option<T>

  abstract xor(another: OptionalValue<T>): Option<T>

  abstract xorWithNone(): Option<T>

  abstract xorWithSome(some: Some<T>): Option<T>

  abstract andThen<U>(fn: (t: T) => Option<U>): Option<U>

  abstract orElse(fn: () => Option<T>): Option<T>

  abstract getOrInsert(value: T): OptionalValue<T>

  abstract getOrInsertWith(fn: () => T): OptionalValue<T>

  abstract takeValue(): Option<T>

  abstract isSomeAnd(andFn: (t: T) => boolean): boolean

  abstract ifSome(param: (t: T) => void): void

  abstract ifNone(fn: () => void): void

  abstract toArray(): T[]

  abstract equalsWith(another: OptionalValue<T>, equality: AreEqual<T>): boolean
}