foreach doesn't, but that's an odd thing to say about map since map has nothing to do with arrays. map iterates over a list, and it has no problem working with a list built from an array.

You are assuming a lack of optimizations and levels of optimization are very much subject to change. I strongly suspect that there are older versions of Perl that didn't optimize foreach over a single array. I suspect that there will be future versions of Perl that can optimize map/grep over a single array. Indeed, I'm not convinced that there aren't already versions of Perl that can optimize such (nor have I seen evidence that there are such, but I prefer to not assume things about levels of optimization exactly because they are so subject to change).

It is merely an optimization that makes foreach treat a single array differently than some other list. There is little to stop map or grep from acquiring a similar optimization. So I find it "odd" for you to make such a stark distinction between them.