memoize.js

export function memoize(fn) {
  var cache = null
  var lastRet = null

  function cacheHit(oldCache, newCache) {
    return oldCache.length == newCache.length &&
      oldCache.every((x,i) => x === newCache[i])
  }

  return (...args) => {
    if(cache===null || !cacheHit(cache, args) ){
      //console.log('cache miss')
      cache = [...args]
      lastRet = fn(...args)
    }
    return lastRet
  }
}


//function add(a,b){
//  return a+b
//}

//const madd = memoize(add)
//console.log(madd(1,3))
//console.log(madd(1,3))
//console.log(madd(1,4))
//console.log(madd(1,3))