Re^3: Doubt on defined-ness

It seems perl applies its magic test for definedness to any while that involves a filehandle (at least, I couldn't find a case where it didn't apply).

$ perl -MO=Deparse -e 'while (<>) {} while ( <ARGV> ) {} while ( $_ = 
+<> ) {} while ( $x = <> ) {}'
while (defined($_ = <ARGV>)) {
    ();
}
while (defined($_ = <ARGV>)) {
    ();
}
while (defined($_ = <ARGV>)) {
    ();
}
while (defined($x = <ARGV>)) {
    ();
}
-e syntax OK
[download]

Unless I state otherwise, all my code runs with strict and warnings

Comment on Re^3: Doubt on defined-ness Download Code

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Re^4: Doubt on defined-ness by ikegami (Patriarch) on Jun 18, 2008 at 22:54 UTC
That's almost the limit. Anything more complex doesn't add a `defined`. `>perl -MO=Deparse -e"while (<FILE> && foo()) {}" while (<FILE> and foo()) { (); } -e syntax OK` [download]	[reply] [d/l] [select]