>>>>> "TS" == Tolkin, Steve <[EMAIL PROTECTED]> writes:
TS> # run using e.g. echo hello | perl this-file
TS> # Why doesn't perl produce a warning from the following. It is an
TS> # infinite loop. If I add a /g modifier to the m// it works fine.
TS> while (<>) {
TS> while (m/([a-z])/) { # warning infinite loop!!!
TS> print $1, "\n"
TS> }
TS> }
if perl could figure out that is an infinite loop, it could also solve
the halting problem. what if the body optionally modified $_ so the m///
failed? how would perl know that is ok but your code is not?
TS> ///
TS> In general it is hard to detect infinite loops, but in this case
TS> it is easy, because the pattern is a constant. I think this is a
TS> very common special case, and is worth detecting.
but the data isn't a constant.
TS> Why isn't this done?
because it can't be done?
uri
--
Uri Guttman ------ [EMAIL PROTECTED] -------- http://www.stemsystems.com
--Perl Consulting, Stem Development, Systems Architecture, Design and Coding-
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