> Now, I love that the for loop can do both of these things, but the subtlety > of the difference in syntax is likely, IMO, to lead to very difficult- > to-find bugs. It's very easy to miss that I've used a comma when I meant to > use a semicolon, and vice versa. And what's the mnemonic again?
Well, I made two (weak) mnemonics for myself. The first is somewhat idiomatic, that @a, @b concatenates the two lists, or, in Perl 5 it did. @a;@b doesn't do that, and it's rather easy to see. The second mnemonic is that I think of doing the two-at-a-time thing as traversing sequentially, or horizontally. Parallel seems more vertical. And semicolon seems a lot more vertical than comma. Yeah, they're stretching a little, but I can quickly tell the difference, and I haven't written a line of Perl 6 code. > Is there any way the syntax could be made different? Could the two > approaches be differently named? Perhaps the first could be C<foreach>, and > the second could be C<for>, and they could both use commas. I would say I wouldn't like that. I've always appreciated for and foreach being synonyms (in fact, I think well chosen synonyms are one of the keys to a highly readable language). So, if the rest of the world is me, you're just being paranoid. But we'll see if anybody else disagrees with me. Luke
