Variable: memoize()

const memoize: <Args, R>(fn, options) => MemoizedFunction<Args, R> = memoizeImpl

Defined in: function/memoize/index.ts:51

Creates a memoized version of a function that caches its results.

This is a simple re-export of the memo module's memoize function, provided here for convenience in the function module.

By default, uses the first argument as the cache key. For custom cache keys, use memo.memoizeBy instead.

Creates a memoized version of a function that caches results based on arguments.

By default, uses a simple Map cache with the first argument as the key. For multi-argument functions or complex keys, use memoizeBy() instead.

Type Parameters

Args

Args extends readonly [unknown, unknown]

R

R

Parameters

fn

(...args) => R

options?

MemoizeOptions = {}

Returns

MemoizedFunction<Args, R>

Example

// Basic memoization
const fibonacci = (n: number): number => {
  if (n <= 1) return n
  return fibonacci(n - 1) + fibonacci(n - 2)
}

const memoFib = memoize(fibonacci)
memoFib(40) // computed (takes time)
memoFib(40) // cached (instant)

// With max size
const getUser = memoize(fetchUser, { maxSize: 100 })

// With TTL
const getWeather = memoize(fetchWeather, { ttl: 5 * 60 * 1000 }) // 5 min

See

• memoizeBy - for custom key extraction
• memoizeAsync - for async functions with deduplication

Examples

const fibonacci = memoize((n: number): number => {
  if (n <= 1) return n
  return fibonacci(n - 1) + fibonacci(n - 2)
})

fibonacci(40)  // Computed once
fibonacci(40)  // Returned from cache instantly

// Memoizing expensive computations
const expensiveCalc = memoize((data: string) => {
  console.log('Computing...')
  return data.split('').reverse().join('')
})

expensiveCalc('hello')  // Logs "Computing...", returns "olleh"
expensiveCalc('hello')  // Returns "olleh" (no log, cached)
expensiveCalc('world')  // Logs "Computing...", returns "dlrow"

// For custom cache keys, use memo.memoizeBy
import { memoizeBy } from 'receta/memo'

const fetchUser = memoizeBy(
  (id: string) => fetch(`/api/users/${id}`).then(r => r.json()),
  (id) => id  // Cache key function
)

See

• memo.memoize - Original implementation with more options
• memo.memoizeBy - For custom cache key generation
• memo.memoizeAsync - For Promise-based memoization