-localtime +gmtime

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Why does -localtime force scalar context but not +localtime?

print -localtime, $/;
print +localtime, $/;
print +gmtime, $/;
print -+gmtime, $/;
__END__
-Fri Nov  6 01:10:44 2009
4417161010953090
4417961010953090
-Fri Nov  6 09:10:44 2009
[download]

Comment on -localtime +gmtime Download Code

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Re: -localtime +gmtime by moritz (Cardinal) on Nov 06, 2009 at 09:58 UTC
B::Deparse to the help: `$ perl -MO=Deparse -e 'print +localtime' print localtime; -e syntax OK $ perl -MO=Deparse -e 'print -localtime' print -localtime; -e syntax OK` [download] The `+` can be used to tell the parser that something isn't part of a function call, it's not a way to tell perl this is a number. We've just discussed this in Re: Split returning one element. In Perl 6 it is a bit different: `foo(..), $x` is always parsed a function call, followed by a comma and `$x`, whereas `foo (...), $x` is parsed a function call which receives both the parenthesis group and `$x`. That leaves the unary + free to force numeric context. Perl 6 - links to (nearly) everything that is Perl 6.	[reply] [d/l] [select]
Re: -localtime +gmtime by ikegami (Patriarch) on Nov 06, 2009 at 16:05 UTC
The no-op operator (unary-plus) doesn't even affect context. It is used to disambiguate parser decisions. Negation requires a number, so it forces numerical context. (Some convenient behaviour was added for when the argument isn't a number.)	[reply]