Re: [wxperl-users] declarative syntax

[Eric W. <scr...@gm...>]

# from Mark Dootson
# on Saturday 17 March 2007 02:13 pm:

>the main attraction to me is getting named accessors for your child
>controls /menus /toolbars etc.

Yes, I think that's fairly key to cleaning up the syntax.  Assignment 
statements which could be taken as implied should be.  The same goes 
for $self (though this is understandably where some people get scared 
and say "whoa, not so fast.")

>I think I'd consider something a touch more verbose

Hmm...  I'm trying to make it *less* verbose and more concise.  What's 
good about verbose?  XML?

>involving Class::Accessor::Fast.

I've run into problems with the typical 'use base qw(Class::Accessor)' 
approach and multiple inheritance.  Maybe I want a new() method from a 
package in which I want to override a foo() method with a generated 
accessor, but the Class::Accessor scheme says "too bad, you get my 
new()."  The solution that I came up with involves letting the accessor 
generator have it's way with a "secret" base class.  While I was at it, 
I realized we can get rid of the whole __PACKAGE__->mk_foo() stuff too.

  http://search.cpan.org/search?module=Class%3A%3AAccessor%3A%3AClassy

>With regard to your WxPerl::Declares section...
>As it stands, the syntax does look very inaccessible.

What specifically makes it inaccessible?  Or, is it just unfamiliar?  I 
understand the aversion to magic, but once you know the trick, it's not 
magic anymore.

Do you have a suggestion (even if you don't think it would compile, I 
would like to see it.)

There are a lot of component parts that I'm trying to put together, and 
I'm trying to leave out any syntax that isn't needed.

Thus, the arguments to children() are a flat list, where the keyword 
'ctrl' (this is actually a subroutine "sub ctrl ($) {$ctrl_token, @_}") 
marks the start of a new control declaration.

  children(
    ctrl custom_bit => 'Thing::Control' => 'argument', 'argument',
    ctrl text_ctrl  => -TextCtrl => "",
         style(te => 'MULTILINE|READONLY|DONTWRAP'),
    ...

You could probably sprinkle some parenthesis in there without breaking 
anything, but that might mean you needed to quote more.  I'm also 
considering having ctrl() be a completely different beast, but I 
haven't come up with a way to manage that without package variables or 
something which otherwise assumes a state.  The benefit of using 
$ctrl_token is that everything is a list of inputs to children() rather 
than individual statements.  This allows children() to handle lots of 
implied stuff such as $self, and I think makes it easier to build the 
single subref which gets installed as the __create_children() method 
(double-underscores are for wxglade replacement compatibility.)

--Eric
-- 
Turns out the optimal technique is to put it in reverse and gun it.
--Steven Squyres (on challenges in interplanetary robot navigation)
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