[jolux]

forEach is actually more powerful than map, you would not be able to use map for side effects in a static and/or lazy language. In a strict, dynamic language, it matters less. Even so I wouldn't describe being an expression vs statement as a difference in power. It's contextual.

[thaumasiotes]

> forEach is actually more powerful than map, you would not be able to use map for side effects in a static and/or lazy language.

You might notice this problem above, where it's necessary to do

  for n in map(reductor, iterable): pass

to realize the mapping.