Re: Comparing references to sub's

Actually after a lot of playing around I got the references to match - but the question is still valid - is comparing ref's to subroutines valid/appropriate (or any reference for that matter), or am I playing a little to close to Perl internals, (the fact that it works in 5.6 may change in 5.8 or 6.0, etc)?

Comment on Re: Comparing references to sub's

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Re^2: Comparing references to sub's by diotalevi (Canon) on Mar 20, 2003 at 01:51 UTC
No, that's normal. Yes, things may/will change in perl 6 (that is a tautology). Compare references using the numeric equality operator. See Re: Why isn't ->can() curried? and Re: Why isn't ->can() curried? for more on comparing references. [Added adrianh has an interesting observation regarding this in Re^3: Comparing references to sub's.] `_detect_type('unzipped.txt') == \&open_unzipped _detect_type('zipped.zip') == \&open_zipped` [download]	[reply] [d/l]
Re: Re: Comparing references to sub's by graff (Chancellor) on Mar 20, 2003 at 02:00 UTC
Comparing references is a stable and well-defined operation: `if ( $thisref eq $thatref ) { # these are two refs address the same object, whatever it is }` [download] (update: as diotalevi has pointed out, the "==" comparison would be more efficient that the "eq", but otherwise the results are equivalent.)	[reply] [d/l]
Re^3: Comparing references to sub's by adrianh (Chancellor) on Mar 20, 2003 at 08:49 UTC
If you want to be really sure you should use `refaddr` from Scalar::Util since the reference type could overload any of `eq`, `==`, `""` or `0+`. Obviously not necessary in this case, but not doing it can catch you out (well, it's caught me out before) if you add overloading at a later date.	[reply] [d/l] [select]