On Sat, 14 Jun 2014 10:20:51 +0000 via Digitalmars-d <digitalmars-d@puremagic.com> wrote:
> On Friday, 13 June 2014 at 21:41:43 UTC, Jonathan M Davis via > Digitalmars-d wrote: > > On Fri, 13 Jun 2014 11:03:14 -0700 > > "H. S. Teoh via Digitalmars-d" <digitalmars-d@puremagic.com> > > wrote: > >> I disagree, it's not a special case. It's simply a logical > >> consequence > >> of each part of the for-loop being optional. Prohibiting > >> for(;;) would > >> *be* a special case, because then you're saying that each > >> component of > >> the for-loop is optional, *except* when all of them are > >> omitted. > >> > >> (Not to mention, for(;1;) is truly an eyesore, far worse than > >> for(;;).) > > > > It's a special case in that the middle portion is supposed to > > be the condition > > that the loop use to determine whether it can continue, and > > omitting it means > > that it has to add the true itself, whereas with the other two > > pieces it makes > > perfect sense that they'd be optional, since they're not > > required to determine > > whether the loop needs to terminate. They're just handy helpers. > > But this special treatment of the second operand is the same in > all forms of the for loop: > > for(int i = 0; ; ++i) // endless loop > > Therefore, the fact that `for(;;)` is also an infinite loop is > not an exception. Regardless of whether there's anything in the other two parts of the loop, it's still ommitting the condition, which IMHO is a special case and incredibly bizarre. Rather than the compiler having a condition to check, suddenly it has to know that it needs to essentially insert true for the condition, because the condition isn't there. This is in contrast to the other two parts of the loop which are handy places to put statements, and having a line with no statement isn't special at all. It's the lack of a condition that I object to. IMHO it's a fundamental violation of how loops work. Unfortunately, however, we're stuck with it. Even if everyone in this thread were in agreement on this (and obviously we're not), it's apparently a long-standing construct from C, so I doubt that Walter would be interested in removing it. - Jonathan M Davis