Is “map” a loop?

Question

While answering this question, I came to realize that I was not sure whether Perl\'s map can be considered a loop or not?

On one hand, it quacks/walks l

Answer 1

Your question turns on the issue of classification. At least under one interpretation, asking whether map is a loop is like asking whether map is a subset of "Loop". Framed in this way, I think the answer is no. Although map and Loop have many things in common, there are important differences.

• Loop controls: Chas. Owens makes a strong case that Perl loops are subject to loop controls like next and last, while map is not.
• Return values: the purpose of map is its return value; with loops, not so much.

We encounter relationships like this all the time in the real world -- things that have much in common with each other, but with neither being a perfect subset of the other.

 -----------------------------------------
|Things that iterate?                     |
|                                         |
|      ------------------                 |
|     |map()             |                |
|     |                  |                |
|     |          --------|----------      |
|     |          |       |          |     |
|     |          |       |          |     |
|      ------------------           |     |
|                |                  |     |
|                |              Loop|     |
|                 ------------------      |
|                                         |
 -----------------------------------------