import { memoize } from "https://deno.land/x/froebel@v0.18.0/function.ts";
Returns a copy of fun that remembers its result for any given arguments and
only invokes fun for unknown arguments.
The cache key is computed using the key function. The default key
function simply stringifies the arguments.
If limit is specified, only the limit-last entries are kept in cache.
The function's cache is available at memoized.cache.
If opt.weak is true, non-primitive cache keys are stored in a WeakMap.
This behavior might for example be useful if you want to memoize some
calculation including a DOM Node without holding on to a reference of that
node.
Using weak keys prohibits setting a limit.
Examples
Example 1
Example 1
const expensiveCalculation = (a: number, b: number) => {
console.log(`calculate ${a} + ${b}`)
return a + b
}
const calc = memoize(expensiveCalculation)
console.log( calc(1, 2) )
// calculate 1 + 2
// 3
console.log( calc(20, 5) )
// calculate 20 + 5
// 25
console.log( calc(20, 5) )
// 25
console.log( calc(1, 2) )
// 3
calc.cache.clear()
console.log( calc(1, 2) )
// calculate 1 + 2
// 3
Example 2
Example 2
const logIfDifferent = memoize(
(msg: string) => console.log(msg),
{
limit: 1,
key: msg => msg
}
)
logIfDifferent('a')
logIfDifferent('a')
logIfDifferent('b')
logIfDifferent('a')
// a
// b
// a