Beefy Boxes and Bandwidth Generously Provided by pair Networks
The stupid question is the question not asked
 
PerlMonks  

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
As merlyn showed me before, you could alternatively use 'can' to check whether $me is an object or not, and leave it alone when it is, trusting that the class of the object is fine:
if ( ref $me and $me->can('can') ){ .....
I did have some discussion with tye about can, and at the time he convinced me to use isa instead: ... $me->isa('UNIVERSAL').

More importantly, reading perlbot I realised that all that caution about bless is unnecessary. So I rephrase my advise above:

There is nothing special about constructors other than that they bless a variable. Since you are allowed to rebless a variable, just call the constructors at will.
In perlbot you can find more info and an example of nested constructors.

Reblessing assumes that the caller knows what (s)he is doing and that the constructor should always return an object of its own class. This antagonizes the logic behind bless-checking. The reblessing approach is the most flexible one, as constructors do not have to make assumptions about which class the returned objects should be in.

This in turn made me realise that multiple inheritance could, with a little caution, even apply to the object's data. Just call both constructors and merge the resulting anonymous arrays. Problems will arise when the inherited classes use the same hash-entries for different purposes or when different types of variables are used, of course. At the end, one just reblesses the anonymous hash.

Jeroen
"We are not alone"(FZ)


In reply to Reblessing (was: OO Perl: calling a constructor within a class) by jeroenes
in thread OO Perl: calling a constructor within a class by fx

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • 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 or How to display code and escape characters are good places to start.
Log In?
Username:
Password:

What's my password?
Create A New User
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others making s'mores by the fire in the courtyard of the Monastery: (10)
As of 2021-06-14 14:42 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?
    What does the "s" stand for in "perls"? (Whence perls)












    Results (62 votes). Check out past polls.

    Notices?