Memoized pattern

memorizador.js

const memoize = ( fn ) => {
  const cache = {}

  return function mfn () {
    const args = [].slice.call( arguments )
    const key = JSON.stringify( args )

    return key in cache
      ? cache[ key ]
      : cache[ key ] = fn.apply( this, args )
  }
}

const fib = ( n ) => 
  ( n < 2 )
    ? n
    : fib( n - 1 ) + fib( n - 2 )

console.time( 'fib' ) 
const tfib = memoize( fib )
console.log( tfib( 43 ) )
console.timeEnd( 'fib' )