> From: Michael C. Davis [mailto:[EMAIL PROTECTED]
> Sent: Friday, 27 February 2004 11:55 PM
> To: [EMAIL PROTECTED]
> Subject: subroutine call weirdness
>
> Hi list,
>
> I just ran across some unexpected results in passing arguments to
> user-defined subroutines. Could someone who has been around
> Perl a while
> longer check this and make sure I'm seeing this right?
>
> I've got some code that implements a constant as a subroutine
> call (to keep
> the constant from being modified). When I use that subroutine in an
> arithmetic expression, it is consuming everything to the
> right of it as its
> argument list.
This is correct. That is why Larry said, "Let there be Prototypes".
Now remember, a perl 'prototype' is not a prototype in the regular
sense,
but a method to override perl's natural greedy argument list collection,
and a method to create functions which emulate perl's builtins (ie,
provide
hints to the expected calling context).
> sub EarliestValidTimestampAsNumber {
>
> # pass in 2000-01-01 00:00:00 as timegm expects it
> # (i.e. as would be returned by gmtime)
> # so that we get correct number of seconds offset from
> start of epoch
>
> return timegm(0, # second zero
> 0, # minute zero
> 0, # hour zero, on
> 1, # the first day of
> 0, # January
> 100 # 2000
> );
> }
might become:
sub EarliestValidTimestampAsNumber () { timegm(0,0,0,1,0,100) }
Hence, the perl compiler *knows* that no arguments could
possibly be passed to the function, and thus none will.
Your test cases should now run properly.
HTH
David
Regards,
David le Blanc
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