rivo/Option/index.d.ts

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import type FlattenFn from "./Flatten";
import type MapFn from "./Map";
import type UnwrapFn from "./Unwrap";
import type UnwrapOrFn from "./UnwrapOr";
import type { IsNoneFn, IsSomeFn, None, OfSomeFn, Some, SomeL } from "./core";
import type { Fn1, PartialApply } from "../HKT";
import type { Lazied } from "../helpers";

/**
 * A type that represents a value that may or may not exist.
 */
export type Option<T = unknown> = Some<T> | None;
/**
 * {@link Lazied} version of {@link Option}.
 */
export type OptionL<L extends Lazied> = SomeL<L> | None;

export type { None, Some, SomeL };

/***********
 * Methods *
 ***********/
/**
 * Methods for `Option`.
 */
export namespace Option {
  /**
   * [Fn] Check if an {@link Option} is {@link None}.
   *
   * Sig: `(o: Option<unknown>) => boolean`
   */
  export type IsNone = IsNoneFn;
  /**
   * [Fn] Check if an {@link Option} is {@link Some}.
   *
   * Sig: `(o: Option<unknown>) => boolean`
   */
  export type IsSome = IsSomeFn;

  /**
   * [Fn] Apply a function to an {@link Option} value if it is {@link Some}, otherwise
   * return {@link None}.
   *
   * Sig: `<T, U>[f: (x: T) => U](o: Option<T>) => Option<U>`
   */
  export type Map<F extends Fn1> = PartialApply<MapFn, [F]>;

  /**
   * [Fn] Flatten an {@link Option} of an {@link Option} into an {@link Option}.
   *
   * Sig: `<T>(o: Option<Option<T>>) => Option<T>`
   */
  export type Flatten = FlattenFn;

  /**
   * [Fn] Get the inner value of an {@link Option} if it is {@link Some}, otherwise return `never`.
   *
   * Type safety is **not guaranteed**.
   *
   * Sig: `<T>(o: Option<T>) => T`
   */
  export type Unwrap = UnwrapFn;
  /**
   * [Fn] Get the inner value of an {@link Option} if it is {@link Some}, otherwise return
   * `Default`.
   *
   * Sig: `<T>[default: T](o: Option<T>) => T`
   */
  export type UnwrapOr<Default> = PartialApply<UnwrapOrFn, [Default]>;
}

/******************
 * Static members *
 ******************/
/**
 * [Fn] Wrap a value in a {@link Some}.
 *
 * Sig: `<T>(value: T) => Some<T>`
 *
 * @example
 * ```typescript
 * type R = $<Option$$OfSome, 42>;
 * //   ^?: Some<42>
 * ```
 */
export type Option$$OfSome = OfSomeFn;

/****************
 * Type classes *
 ****************/
export type { Option$$HKT$$Builder, Option$$HKT$$Extractor } from "./HKT";

export type { Option$$Applicative } from "./Applicative";
export type { Option$$Functor } from "./Functor";
export type { Option$$Monad } from "./Monad";
export type { Option$$Ord } from "./Ord";
export type { Option$$Show } from "./Show";