detecting code referece

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

When having a reference, how can i detect what the data type is that it holds? Although perl is loosely typed, one still has warning/error messages that such or such variable isn't the array/hash/code you were looking for. Therefore there could be a way under certain circumstances.

my $result = do_me();
#is $result a code referece? -> $result->()
#is $result a scalar?
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Re: detecting code referece by moritz (Cardinal) on Dec 17, 2007 at 10:01 UTC
Look at ref.	[reply]
Re^2: detecting code referece by dragonchild (Archbishop) on Dec 17, 2007 at 14:51 UTC
Scalar::Util's reftype is safer because it avoids the case where the object is blessed into the class 'CODE'. My criteria for good software: Does it work? Can someone else come in, make a change, and be reasonably certain no bugs were introduced?	[reply]
Re: detecting code referece by Gangabass (Vicar) on Dec 17, 2007 at 10:02 UTC
Just use search	[reply]
Re: detecting code referece by ysth (Canon) on Dec 17, 2007 at 16:23 UTC
In general, you should avoid designing APIs that need to know. What if $result is an object intended to be interpreted as a scalar (i.e. overloaded) that happens to really be a blessed code reference? -- CollegeGear.com - more than just college gear (though, yes, we have college-branded teddy bears)	[reply]
Re^2: detecting code referece by chromatic (Archbishop) on Dec 17, 2007 at 19:02 UTC
Even more surprising, what if `$result` is a blessed scalar with `&{}` overloaded? In general, in Perl, there's no foolproof way of knowing the operations you can perform on a reference without performing the operation.	[reply] [d/l] [select]