memoize source npm

_.memoize(func, [resolver])

Creates a function that memoizes the result of func. If resolver is provided it determines the cache key for storing the result based on the arguments provided to the memoized function. By default, the first argument provided to the memoized function is used as the map cache key. The func is invoked with the this binding of the memoized function.

Note: The cache is exposed as the cache property on the memoized function. Its creation may be customized by replacing the _.memoize.Cache constructor with one whose instances implement the Map method interface of get, has, and set.

Arguments

  1. func (Function)

    The function to have its output memoized.

  2. [resolver] (Function)

    The function to resolve the cache key.

Returns (Function)

Returns the new memoizing function.

Example

var object = { 'a': 1, 'b': 2 };
var other = { 'c': 3, 'd': 4 };

var values = _.memoize(_.values);
values(object);
// => [1, 2]

values(other);
// => [3, 4]

object.a = 2;
values(object);
// => [1, 2]

// modifying the result cache
values.cache.set(object, ['a', 'b']);
values(object);
// => ['a', 'b']

// replacing `_.memoize.Cache`
_.memoize.Cache = WeakMap;