message: feat(chunk): implement map
diff: @@ -714,3 +714,28 @@ export function drop(n: number): <A>(self: Chunk<A>) => Chunk<A> {
  export function size<A>(self: Chunk<A>) {
  return self.length
  }
  +
  +/**
  + * Returns a chunk with the elements mapped by the specified function.
  + */
  +export function map_<A, B>(self: Chunk<A>, f: (a: A) => B): Chunk<B> {
  + const arr = self.toArray()
  + const len = arr.length
  + const r = new Array<B>(len)
  + for (let i = 0; i < len; i++) {
  + const k = arr[i]
  + if (k) {
  + r[i] = f(k)
  + }
  + }
  + return fromArray(r)
  +}
  +
  +/**
  + * Returns a chunk with the elements mapped by the specified function.
  + *
  + * @dataFirst map_
  + */
  +export function map<A, B>(f: (a: A) => B): (self: Chunk<A>) => Chunk<B> {
  + return (self) => map_(self, f)
  +}
  