Re: [pygccxml-development] need help with query

[Roman Y. <rom...@gm...>]

On 3/15/06, Matthias Baas <ba...@ir...> wrote:
> Roman Yakovenko wrote:
> > I saw Matthias filters ( Or, Not and And ) and liked the idea. But (
> > there is always some 'but' :-( ).
> >
> > I don't think they are useful in the form like this. People are to
> > lazy to learn. So instead
> > of composing queries using Matthias classes, they will right small
> > lambda function that will
> > do the job. May be I wrong, may be not. I propose an other
> > implementation. Take a look on attached file. Right now it does not
> > work. This is the area I need help. Can you see what I am doing wrong?
> >
> > Lets say I have query class, that has __call__ method, that takes 1
> > argument - some text
> >
> > qa =3D query_t( 'a' ) #returns true if 'a' in text
> > qb =3D query_t( 'b' ) #returns true if 'b' in text
> >
> > qab =3D qa and qb
> > [...]
> > qaqb =3D qa or qb
>
> The above lines should read:
>
> qab =3D qa & qb
> ...
> qaqb =3D qa | qb
>
> "and", "or" is not the same as the &,| operators.
>
> > Do you like such approach? Matthias what do you think?
>
> I don't understand what problem you want to solve. Your query class just
> does the same than my filters, but above you say that this is too
> difficult to learn...? So in what respect is query_t easier to use than
> my filters?

By the way, I could be wrong. I just want a discuss this a little.

OrFilter and AndFilter takes as argument list of filters right. I
think that in most case
an user does not have more then 2 or 3 filters. I could be wrong. So I
think, user will not use next code

f1 =3D filter(....)
f2 =3D filter(...)

mb =3D module_builder_t(...)
mb.classes( OrFilter( [f1,f2] ) )

but rather:

mb.classes( lambda decl: f1(decl) or f2(decl) )

I could be wrong, but in this case he will not learn OrFilter. If we
implement your idea
in a different way, then user can write next line

mb.classes( f1 | f2 )

> - Matthias -

I hope, I was clear. I do like your idea, but I think it should be
improved a little.

--
Roman Yakovenko
C++ Python language binding
http://www.language-binding.net/