2009/3/11 Jim Gibson <jimsgib...@gmail.com>:
> On 3/11/09 Wed Mar 11, 2009 5:28 AM, "Dermot" <paik...@googlemail.com>
> scribbled:
>
>> 2009/3/11 Dr.Ruud <rvtol+use...@isolution.nl>:
>>> Dermot wrote:
>>>
>>>> I created a small Class, initially with Moose. When I wanted an
>>>> instance of the class I would call `my $instance = new MyClass`;
>>>>
>>>> I then removed Moose and went for a standard Perl 00 constructor:
>>>>
>>>> sub new {
>>>> my $class = shift;
>>>> my $self = {};
>>>> $self->{config} = _get_config();
>>>> bless ($self, $class);
>>>> return $self;
>>>> }
>>>>
>>>> I haven't changed the way I created an instance, and it still works. I
>>>> would have thought I would have to create instances now with
>>>>
>>>> my $instance = MyClass->new;
>>>>
>>>> Are both assignments legit?
>>>
>>> There is even a third way:
>>>
>>> MyClass::->new
>>>
>>> and a fourth way:
>>>
>>> MyClass::->new()
>>
>> So do they all amount to the same thing? I can see that the 4th way
>> would allow you to pass arguments. When you read the docs for modules
>> they (all the one's I can recall) show either
>>
>> my $inst = new Some::Module;
>>
>> or
>>
>> my $inst = Some::Module->new;
>>
>> I thought there was some black art to allow you to make a constructor
>> work with the first example.
>
> They are mostly equivalent (you can add argumets to the first call, too).
> There are potential compiler problems with the first form, as it is more
> difficult for the compiler to figure out which package's new method should
> be called if you generate the module name with a function or constant. For
> this reason, the form Some::Module->new() is preferred.
>
> See "Object Oriented Perl", by Damian Conway, pp 98 for details.
I see. Thanx.
Dp.
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