The problem with just UNIVERSAL::can($ref,'isa') is that it can return a true value when $ref isn't even a reference. So you really have to make multiple tests:
if( ! ref($r) ) {
# no reference at all
} elsif( ! UNIVERSAL::can($r,'can') ) {
# unblessed ref
} else {
# blessed ref
}
or just:
if( ref($r) && UNIVERSAL::can($r,'can') ) {
# blessed ref
}
or
if( ref($r) && eval { $r->can('can') } ) {
# blessed ref
}
and I can't make a convincing case for one style over the other at the moment.
And, yes, it would be nice if there were less overloaded versions of these things so that blessed returned the package that a reference was blessed into and ref just always returned the type of thing. That was a certainly a design mistake IMO.
-
tye
(but my friends call me "Tye")
-
Are you posting in the right place? Check out Where do I post X? to know for sure.
-
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
<u> <ul>
-
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).
-
Want more info? How to link
or How to display code and escape characters
are good places to start.
|