To quote Nikolaus Wirth on this one: the "for" loop is just syntactic sugar. There is no need for the different type of loops, they are just nice to look at (i.e. you can rewrite every loop using anoother one). That's why Oberon (successor of Modula 2, successor of Pascal) doesn't have a "for" statement.

The reason why "for" is handled by rewriting it to a "while" construct: well, reuse, I guess. Since all loops are in essence equivalent, you choose one which is easy to implement and transform the others on the fly. Compiler gurus, your call ;-)

Andreas