But I'll make the contention that anyone who becomes familiar with how "map" works, will find code using that operator easier to come back to, as opposed to coming back to code which uses willy-nilly "for" loops. I see it similar to GOTO's. Inexperienced programmers have no problem using them. Better programers though, appreciate the invariants that come with using higher level constructs. Besides, I wouldn't trust a programmer that knows perfectly well how "map" works, but decides that they prefer to reinvent their own list traversal schemes.