const map = (mapperFn) => {
  const mapFn = (arr) => arr.map(mapperFn);

  // closure
  return mapFn;
};

const filter = (filterring)=>{
  const filterFn=()=>{
    arr.filter(filterring)
  }
  return filterFn

}

const split = (splitFn)=>{
  const spltFn=(arr)=>arr.split(splitFn)

  return spltFn

};

const concat = (arr2)=>{
  const conFn=(arr)=>arr.concat(arr2)
  return conFn
};

const reverse = ()=>{
  const reverseFn=(arr)=>arr.reverse()
  return reverseFn
};

const join = (args)=>{
  const joined=(arr)=>arr.join(args)
  return joined
};

// const zip = (...arrs)=>{
//   const zipFn=()=>{
//     let newArr=[],

//   }
// };

const compose = (...funcs)=>{
  funcs.forEach(element => {
    return element(str)
  });
};

const flip = undefined;

module.exports = {
  split,
  filter,
  map,
  reverse,
  join,
  concat,
  //zip,
  compose,
  flip
};