@solana/options
Version:
Managing and serializing Rust-like Option types in JavaScript
102 lines • 3.66 kB
TypeScript
import { None, Some } from './option';
/**
* Defines types that should not be recursively unwrapped.
*
* These types are preserved as-is when using {@link unwrapOptionRecursively}.
*
* @see {@link unwrapOptionRecursively}
*/
type UnUnwrappables = Date | Int8Array | Int16Array | Int32Array | Uint8Array | Uint16Array | Uint32Array | bigint | boolean | number | string | symbol | null | undefined;
/**
* A type that recursively unwraps nested {@link Option} types.
*
* This type resolves all nested {@link Option} values, ensuring
* that deeply wrapped values are properly extracted.
*
* - If `T` is an {@link Option}, it resolves to the contained value.
* - If `T` is a known primitive or immutable type, it remains unchanged.
* - If `T` is an object or array, it recursively unwraps any options found.
*
* The fallback type `U` (default: `null`) is used in place of `None` values.
*
* @typeParam T - The type to be unwrapped.
* @typeParam U - The fallback type for `None` values (defaults to `null`).
*
* @example
* Resolving nested `Option` types.
* ```ts
* UnwrappedOption<Some<Some<string>>>; // string
* UnwrappedOption<None>; // null
* ```
*
* @example
* Resolving options inside objects and arrays.
* ```ts
* UnwrappedOption<{ a: Some<number>; b: None }>; // { a: number; b: null }
* UnwrappedOption<[Some<number>, None]>; // [number, null]
* ```
*
* @see {@link unwrapOptionRecursively}
*/
export type UnwrappedOption<T, U = null> = T extends Some<infer TValue> ? UnwrappedOption<TValue, U> : T extends None ? U : T extends UnUnwrappables ? T : T extends object ? {
[key in keyof T]: UnwrappedOption<T[key], U>;
} : T extends Array<infer TItem> ? Array<UnwrappedOption<TItem, U>> : T;
/**
* Recursively unwraps all nested {@link Option} types within a value.
*
* This function traverses a given value and removes all instances
* of {@link Option}, replacing them with their contained values.
*
* - If an {@link Option} is encountered, its value is extracted.
* - If an array or object is encountered, its elements are traversed recursively.
* - If `None` is encountered, it is replaced with the fallback value (default: `null`).
*
* @typeParam T - The type of the input value.
* @typeParam U - The fallback type for `None` values (defaults to `null`).
*
* @param input - The value to unwrap.
* @param fallback - A function that provides a fallback value for `None` options.
* @returns The recursively unwrapped value.
*
* @example
* Recursively unwrapping nested options.
* ```ts
* unwrapOptionRecursively(some(some('Hello World'))); // "Hello World"
* unwrapOptionRecursively(some(none<string>())); // null
* ```
*
* @example
* Recursively unwrapping options inside objects and arrays.
* ```ts
* unwrapOptionRecursively({
* a: 'hello',
* b: none(),
* c: [{ c1: some(42) }, { c2: none() }],
* });
* // { a: "hello", b: null, c: [{ c1: 42 }, { c2: null }] }
* ```
*
* @example
* Using a fallback value for `None` options.
* ```ts
* unwrapOptionRecursively(
* {
* a: 'hello',
* b: none(),
* c: [{ c1: some(42) }, { c2: none() }],
* },
* () => 'Default',
* );
* // { a: "hello", b: "Default", c: [{ c1: 42 }, { c2: "Default" }] }
* ```
*
* @remarks
* This function does not mutate objects or arrays.
*
* @see {@link Option}
* @see {@link UnwrappedOption}
*/
export declare function unwrapOptionRecursively<T>(input: T): UnwrappedOption<T>;
export declare function unwrapOptionRecursively<T, U>(input: T, fallback: () => U): UnwrappedOption<T, U>;
export {};
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