cacheSize option for defaultMemoize

[b6pzeusbc54tvhw5jgpyw8pwz2x6gs]

As 3rd argument, now defaultMemoize() can get the cacheSize.

There are two arrays to store previous argument arrays, previous results.

let cacheArgsArr = []
let cacheREsultArr = []

cacheSize feature is designed as follows:

const createSelector = createSelectorCreator( defaultMemoize, void 0, 2 )
const powerSelector = createSelector([
      (state)=>state.num
], ( num )=> num*num )

console.log( powerSelector({ num: 1 }) )            // 1 (recomputation)
console.log( powerSelector.getCacheArgsArr() )      // [ [1] ]
console.log( powerSelector.getCacheResultArr() )    // [1]

console.log( powerSelector({ num: 2 }) )            // 4 (recomputation)
console.log( powerSelector.getCacheArgsArr() )      // [ [2],[1] ]
console.log( powerSelector.getCacheResultArr() )    // [ 4, 1 ]

console.log( powerSelector({ num: 3 }) )            // 9 (recomputation)
console.log( powerSelector.getCacheArgsArr() )      // [ [3],[2] ]
console.log( powerSelector.getCacheResultArr() )    // [ 9, 4 ]

console.log( powerSelector({ num: 2 }) )            // 4 (cache)
console.log( powerSelector.getCacheArgsArr() )      // [ [2],[3] ]
console.log( powerSelector.getCacheResultArr() )    // [ 4, 9 ]

In general, there is high a probability that last argument is used again.
So last arguemnts and result are added or updated to index: 0 in cacheArgsArrandcacheResultArr`

Please feel free to contact us if you have something lacking.

[codecov-io]

Current coverage is 100% (diff: 100%)

Merging #210 into master will not change coverage

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Powered by Codecov. Last update 1143dcb...484b0a1

[coveralls]

Coverage remained the same at 100.0% when pulling 484b0a1 on b6pzeusbc54tvhw5jgpyw8pwz2x6gs:master into 1143dcb on reactjs:master.

[coveralls]

Coverage remained the same at 100.0% when pulling 484b0a1 on b6pzeusbc54tvhw5jgpyw8pwz2x6gs:master into 1143dcb on reactjs:master.

[coveralls]

Coverage remained the same at 100.0% when pulling 484b0a1 on b6pzeusbc54tvhw5jgpyw8pwz2x6gs:master into 1143dcb on reactjs:master.

[coveralls]

Coverage remained the same at 100.0% when pulling 484b0a1 on b6pzeusbc54tvhw5jgpyw8pwz2x6gs:master into 1143dcb on reactjs:master.

[ivawzh]

Thank @b6pzeusbc54tvhw5jgpyw8pwz2x6gs , this was an enlightenment.
What do you think about the already supported selector customization below:

import memoizer from 'fast-memoize'
import { createSelectorCreator } from 'reselect'

// Why not Lodash's memoize?
// Because that won't work when the function takes more than one argument. And this is fast.

export const createSelector = createSelectorCreator(memoizer)

fast-memoize allows unlimited cache size.

[adnelson]

@ivawzh that's a great solution -- it would be super helpful if this were in the README.md. It suggests to "Create a custom selector with a cache size greater than one." But doesn't provide any guidance on how to do so.

[markerikson]

Superseded by #513 .