Re: while ()

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Re^2: while () by blazar (Canon) on Jun 07, 2005 at 16:38 UTC
I think so too. However perlsyn suggest that it is C-style `for` which is really a `while` loop in disguise and not the other way round.	[reply] [d/l] [select]
Re^3: while () by ikegami (Patriarch) on Jun 07, 2005 at 16:47 UTC
If `for` is really a `while` in disguise, maybe they allowed `while` to have a empty condition to create a simple transformation from `for` to `while`. In other words, if `for (a; b; c) { d }` [download] is translated into `a; while (b) { d } continue { c }` [download] having the `while` accept an empty condition simplifies the translation. By the way, C doesn't allow an empty `while` condition: a.cpp:5: ANSI C++ forbids an empty condition for `while'	[reply] [d/l] [select]
Re^2: while () by ambrus (Abbot) on Jun 08, 2005 at 14:59 UTC
I agree. The phenomenon that `for` in perl is equivalent to `while` is best shown in that `for(;<>;){` has the same magic as `while(<>){`. Also I note that `until(){` is accepted too, and it seems to mean `until(1){`, that is, it's not executed at all. Of course, `while()` means `while(1)` only as a prefix while. A suffix `while ();` has an empty list in its condition as expected, so it doesn't execute at all, a suffix `while;` is an error, and the results for `until` is similar.	[reply] [d/l] [select]