domenic at domenicdenicola.com (2014-06-10T19:05:41.337Z)
Why not accept these as for-loop initializations, so that x actually has that function and that class as its initial value in the first iteration of the loop? To me, that's the least surprise. Since this is a position in which some declarations are accepted, anything there that looks like a declaration should be a declaration. However, I agree that banning these is much less surprising than allowing them as expressions rather than declarations.
Why not accept these as for-loop initializations, so that x actually has that function and that class as its initial value in the first iteration of the loop? To me, that's the least surprise. Since this is a position in which some declarations are accepted, anything there that looks like a declaration should be a declaration. However, I agree that banning these is much less surprising than allowing them as expressions rather than declarations. On Thu, Jun 5, 2014 at 7:58 AM, Andreas Rossberg <rossberg at google.com> wrote: > C-style for-loops allow declarations as init statements, but only some > of them. Yet, the others (function and class) are actually > syntactically legal in that position as well, because they are simply > parsed as expressions. Consider: > > let x = 0 > for (let x = 1; ;) x // 1 > for (const x = 1; ;) x // 1 > for (function x(){}; ;) x // 0 > for (class x(){}; ;) x // 0 > > I think these latter two examples violate the principle of least > surprise. I wonder if it wouldn't be cleaner to rule them out, by > imposing the same lookahead restrictions on for-loop init expressions > as there are for expression statements. > > The one caveat is that for function, that would actually be a breaking > change, but is it likely to be a real world one? > > What do you think? > > /Andreas > _______________________________________________ > es-discuss mailing list > es-discuss at mozilla.org > https://mail.mozilla.org/listinfo/es-discuss > -- Cheers, --MarkM -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.mozilla.org/pipermail/es-discuss/attachments/20140605/c756b50b/attachment.html>