in reply to Prototype Failing?

Prototypes are not honoured on method calls. You passed an array and received and array. For the low-down on why, read on in the same document to the secion that starts

Method calls are not influenced by prototypes either, ...

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Re: Re: Prototype Failing?
by Flame (Deacon) on Jan 27, 2003 at 04:49 UTC
    Ok, so the first call was as a method, but the second was internal... a method calling a function, shouldn't it have honored the prototype then?

    _self is the only one with a prototype that needs to be payed attention to and it's being called as a function.


    My code doesn't have bugs, it just develops random features.

    Flame ~ Lead Programmer: GMS (DOWN) | GMS (DOWN)

[reply]

      The first argument in @_ in a method call is self.

      When you call _self(@_) you are passing a reference to an array, the first element of which is a bless'd reference. (in this case a hashref).

      When you give the array ref to Dumper, it duly dumps contents of the hash followed by the individual elements of the rest of @_. Ie. the list you passed to selftest().

      When you try to dereference the first element of @_ as an array ref in ref($_[0]->[0]), it complains because $_[0] is a hashref (self) as magically supplied to selftest() when you invoked it as a method.

      Hope that makes sense of it.

      Examine what is said, not who speaks.

      The 7th Rule of perl club is -- pearl clubs are easily damaged. Use a diamond club instead.

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        Sorry, you lost me there, but it's ok... It's working now (Re: Prototype Failing?)

        The problem was, it wasn't being convered to a reference, otherwise @_ would have dumped as a reference instead of $VAR1 $VAR2 $VAR...


        My code doesn't have bugs, it just develops random features.

        Flame ~ Lead Programmer: GMS (DOWN) | GMS (DOWN)

[reply]
        Actually, the call to $result= function(@some_args); is not a "method call" even if the first item in the array will subsequently be treated as an object. This is a regular function call, and will use normal sub lookup rules. It is semantically different from writing $some_args[0]->function(@some_args[1..$#some_args]); which will use the virtual calling mechanism and blessings to figure out which package's function to call first (and meanwhile ignore any prototypes).

        The real answer here is: use strict; use warnings; It will tell you that the prototype is ignored and why!

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