// env::common.js

const toString = require('./src/toString') // R.string

const maxScore = 100

function memorizeForMe (fn) {
  const cache = new Map()
  const cacheScore = new Map()
  return (...args) => {
    // NOTE: toString() since it can handle complex structures.
    const id = toString(args)
    // Decrease score for all ids, except current
    cacheScore.forEach((v, k, i) => {
      if(k === id) return
      // Purge old cache
      if(v <= 1) {
        i.delete(k)
        cache.delete(k)
        return
      }
      // Decrease value of other entries
      return i.set(k, v - 1)
    })
    if(cache.has(id)) {
      return cache.get(id)
    }
    const result = fn(...args)
    // Cache the result
    cache.set(id, result)
    // And assign maxScore to the new entry, it
    // will decrease over time
    cacheScore.set(id, maxScore)
    return result
  }
}

const rand = memorizeForMe(() => Math.random())
const k = [rand(1), rand(), rand(2), rand(1)]
console.log(k)
//[
  //0.10202677372401414,
  //0.07587689343613024,
  //0.7744437228888266,
  //0.10202677372401414
//]