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Postings from March 2008
Something I ran into while toying with Merijn's idea of freezing time
(as presented on the last NL Perl Mongers meeting).
$ perl -le 'print scalar localtime( () )'
Thu Jan 1 01:00:00 1970
$ perl -le 'print scalar gmtime( () )'
Thu Jan 1 00:00:00 1970
Note the extra () specified.
Similarly:
$ perl -le '$_ = []; print ref( )'
ARRAY
$ perl -le '$_ = []; print ref( () )'
If this is intended behaviour, I wonder how you can destinguish
between no parameters specified, and an empty list specification from
within a called subroutine?
$ perl -wle 'sub a { print scalar @_ } a';
0
$ perl -wle 'sub a { print scalar @_ } a()';
0
$ perl -wle 'sub a { print scalar @_ } a( () )';
0
Checking @_ clearly doesn't help. Checking caller() neither:
$ perl -wle 'sub a { print +(caller(0))[4] } &a';
0
$ perl -wle 'sub a { print +(caller(0))[4] } a';
1
$ perl -wle 'sub a { print +(caller(0))[4] } a()';
1
$ perl -wle 'sub a { print +(caller(0))[4] } a( () )';
1
The reason I'm asking, is that I want to be able to completely mimic
the behaviour of builtins when they're wrapped by custom code: it
would seem to me that that is basically impossible at the moment. Or
am I missing something?
Liz
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