module@warp-drive/alien-signals/primitives

Function createMemo() sincev5.10.0

function createMemo<T>(
   obj: object, 
   key: string | symbol, 
   fn: () => T
): MemoNode<T>;

Defined in: primitives.ts:259

Creates a MemoNode that caches the result of fn. Read it with readMemo: the first read runs fn, and later reads return the cached result until a signal or memo fn read changes. If fn throws, the error is cached and rethrown by each read until then.

Type Parameters

T

T

Parameters

obj

object

the object the memo belongs to, kept for debugging in development builds

key

string | symbol

the key the memo is for, kept for debugging in development builds

fn

() => T

the function whose result to cache

Returns

MemoNode<T>

a new memo, which has not run fn yet

Example

import { createMemo, readMemo } from '@warp-drive/alien-signals/primitives';

const fullName = createMemo(user, 'fullName', () => `${user.firstName} ${user.lastName}`);
readMemo(fullName); // runs the function
readMemo(fullName); // returns the cached result