pygccxml-development

[pygccxml-development] Removing template default arguments?

[Gustavo C. <gjc...@gm...>]

2008/8/26 Roman Yakovenko <rom...@gm...>

> On Tue, Aug 26, 2008 at 8:28 AM, Roman Yakovenko
> <rom...@gm...> wrote:
> > On Tue, Aug 26, 2008 at 1:58 AM, Gustavo Carneiro <gjc...@gm...>
> wrote:
> >> Sorry, I just discovered it's not a bug.  It's not infinite recursion,
> just
> >> very slow :P
> >
> > This is also bug. I would like to see your use case, so I can improve it.
> >
> > The first obvious think we can do is to add cache for element_type
> > method. This should dramatically improve the speed of your application
> > - or discover another bottleneck.
> >
> >> It turns out that
> >> pygccxml.declarations.container_traits.xxx_traits.element_type() is
> rather
> >> slow and I was calling it more often than I should.
> >>
> >> Now, I am left with the old problem of distinguishing between sequence
> and
> >> mapping containers... </hint>
> >
> > :-). I will work on this today.
>
> done.
>
> http://pygccxml.svn.sourceforge.net/viewvc/pygccxml?view=rev&revision=1408
>
> I also added cache for element_type and key_type functionality. Let me
> know whether this change improved performance or not.


Thanks, Roman, it is indeed much faster now! :-)

I have one more tricky question.   I am getting this key_type:

    std::basic_string<char,std::char_traits<char>,std::allocator<char> >
[struct]

Now, I know this is just a std::string type, but PyBindGen does not know
it.  Is there any way to convert this into a simpler std::string -like
definition.  That is because I register and lookup types by type expression
string, but if there are multiple definitions for the same type then things
won't match.

Well, I guess one solution for me would be to register the
"std::basic_string<char, std::char_traits<char>, std::allocator<char> >"
type string alongside std::string, but if there's anything better to do I'll
take it.

I guess this is a generic question.  Given the simple test case I am working
on:

   std::map<std::string, int>

pygccxml reads this as:

   std::map<std::basic_string<char, std::char_traits<char>,
std::allocator<char> >,int,std::less<std::basic_string<char,
std::char_traits<char>, std::allocator<char> >
>,std::allocator<std::pair<const std::basic_string<char,
std::char_traits<char>, std::allocator<char> >, int> > >

Is there any easy way to just remove the template arguments that have the
same value as the template default template argument value?

I am guessing the answer is no, but it doesn't hurt to ask :P

-- 
Gustavo J. A. M. Carneiro
INESC Porto, Telecommunications and Multimedia Unit
"The universe is always one step beyond logic." -- Frank Herbert

Re: [pygccxml-development] Removing template default arguments?

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

On Tue, Aug 26, 2008 at 3:09 PM, Gustavo Carneiro <gjc...@gm...> wrote:
> Thanks, Roman, it is indeed much faster now! :-)
>
> I have one more tricky question.   I am getting this key_type:
>
>     std::basic_string<char,std::char_traits<char>,std::allocator<char> >
> [struct]
>
> Now, I know this is just a std::string type, but PyBindGen does not know
> it.  Is there any way to convert this into a simpler std::string -like
> definition.  That is because I register and lookup types by type expression
> string, but if there are multiple definitions for the same type then things
> won't match.
>
> Well, I guess one solution for me would be to register the
> "std::basic_string<char, std::char_traits<char>, std::allocator<char> >"
> type string alongside std::string, but if there's anything better to do I'll
> take it.
>
> I guess this is a generic question.  Given the simple test case I am working
> on:
>
>    std::map<std::string, int>
>
> pygccxml reads this as:
>
>    std::map<std::basic_string<char, std::char_traits<char>,
> std::allocator<char> >,int,std::less<std::basic_string<char,
> std::char_traits<char>, std::allocator<char> >
>>,std::allocator<std::pair<const std::basic_string<char,
> std::char_traits<char>, std::allocator<char> >, int> > >
>
> Is there any easy way to just remove the template arguments that have the
> same value as the template default template argument value?
>
> I am guessing the answer is no, but it doesn't hurt to ask :P

Wrong guess: http://language-binding.net/pygccxml/apidocs/pygccxml.declarations.declaration.declaration_t-class.html#partial_name

By the way, container_traits has "remove_defaults" functionality. Now,
you know what it is for.

This is a must functionality for a good code generator - the generated
code should be as closed to "human written" as possible.

HTH

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

Re: [pygccxml-development] Removing template default arguments?

[Gustavo C. <gjc...@gm...>]

2008/8/26 Roman Yakovenko <rom...@gm...>

> On Tue, Aug 26, 2008 at 3:09 PM, Gustavo Carneiro <gjc...@gm...>
> wrote:
> > Thanks, Roman, it is indeed much faster now! :-)
> >
> > I have one more tricky question.   I am getting this key_type:
> >
> >     std::basic_string<char,std::char_traits<char>,std::allocator<char> >
> > [struct]
> >
> > Now, I know this is just a std::string type, but PyBindGen does not know
> > it.  Is there any way to convert this into a simpler std::string -like
> > definition.  That is because I register and lookup types by type
> expression
> > string, but if there are multiple definitions for the same type then
> things
> > won't match.
> >
> > Well, I guess one solution for me would be to register the
> > "std::basic_string<char, std::char_traits<char>, std::allocator<char> >"
> > type string alongside std::string, but if there's anything better to do
> I'll
> > take it.
> >
> > I guess this is a generic question.  Given the simple test case I am
> working
> > on:
> >
> >    std::map<std::string, int>
> >
> > pygccxml reads this as:
> >
> >    std::map<std::basic_string<char, std::char_traits<char>,
> > std::allocator<char> >,int,std::less<std::basic_string<char,
> > std::char_traits<char>, std::allocator<char> >
> >>,std::allocator<std::pair<const std::basic_string<char,
> > std::char_traits<char>, std::allocator<char> >, int> > >
> >
> > Is there any easy way to just remove the template arguments that have the
> > same value as the template default template argument value?
> >
> > I am guessing the answer is no, but it doesn't hurt to ask :P
>
> Wrong guess:
> http://language-binding.net/pygccxml/apidocs/pygccxml.declarations.declaration.declaration_t-class.html#partial_name
>

Awesome!

Unfortunately I found a small problem with it:

************* register_container std::map< std::basic_string< char,
std::char_traits< char >, std::allocator< char > >, int, std::less<
std::basic_string< char, std::char_traits< char >, std::allocator< char > >
>, std::allocator< std::pair< const std::basic_string< char,
std::char_traits< char >, std::allocator< char > >, int > > >;
element_type=int, key_type=string

key_type should be 'std::string', not 'string', right?


>
> By the way, container_traits has "remove_defaults" functionality. Now,
> you know what it is for.


remove_defaults rocks as well, but has the same problem of removing the
std:: namespace prefix.


> This is a must functionality for a good code generator - the generated
> code should be as closed to "human written" as possible.


Agreed.

-- 
Gustavo J. A. M. Carneiro
INESC Porto, Telecommunications and Multimedia Unit
"The universe is always one step beyond logic." -- Frank Herbert

Re: [pygccxml-development] Removing template default arguments?

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

On Tue, Aug 26, 2008 at 4:25 PM, Gustavo Carneiro <gjc...@gm...> wrote:
> Unfortunately I found a small problem with it:
>
> ************* register_container std::map< std::basic_string< char,
> std::char_traits< char >, std::allocator< char > >, int, std::less<
> std::basic_string< char, std::char_traits< char >, std::allocator< char > >
>>, std::allocator< std::pair< const std::basic_string< char,
> std::char_traits< char >, std::allocator< char > >, int > > >;
> element_type=int, key_type=string
>
> key_type should be 'std::string', not 'string', right?

Can you submit small test case that reproduce the problem?

Thanks

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

Re: [pygccxml-development] Removing template default arguments?

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

On Tue, Aug 26, 2008 at 5:09 PM, Gustavo Carneiro <gjc...@gm...> wrote:
> Attached.

Okey. There is no bug in pygccxml, if I look on your test case.
I still don't understand how you get std::map< string, int >?

I would like to explain few things, that I hope, will make clear to
you what and how to use.

declaration_t class has 4 different properties, related to its name

I will explain them, using the following example:

namespace ns{
    std::vector< int > do_smth();
}

For do_smth return type:

* name - the class name - vector< int, std::allocator< int > >
* partial name - the class name without default template args - vector< int >
* decl_string - full class name - std::vector< int, std::allocator< int > >
* partial_decl_string - the full class name without default template
args - std::vector< int >

In most case, you want to use [partial_]decl_string, because it allows
you to use the class in "other context".

HTH

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

Re: [pygccxml-development] Removing template default arguments?

[Gustavo C. <gjc...@gm...>]

2008/8/26 Roman Yakovenko <rom...@gm...>

> On Tue, Aug 26, 2008 at 5:09 PM, Gustavo Carneiro <gjc...@gm...>
> wrote:
> > Attached.
>
> Okey. There is no bug in pygccxml, if I look on your test case.
> I still don't understand how you get std::map< string, int >?
>
> I would like to explain few things, that I hope, will make clear to
> you what and how to use.
>
> declaration_t class has 4 different properties, related to its name
>
> I will explain them, using the following example:
>
> namespace ns{
>    std::vector< int > do_smth();
> }
>
> For do_smth return type:
>
> * name - the class name - vector< int, std::allocator< int > >
> * partial name - the class name without default template args - vector< int
> >
> * decl_string - full class name - std::vector< int, std::allocator< int > >
> * partial_decl_string - the full class name without default template
> args - std::vector< int >
>
> In most case, you want to use [partial_]decl_string, because it allows
> you to use the class in "other context".


partial_decl_string works perfectly.  Thank you!

-- 
Gustavo J. A. M. Carneiro
INESC Porto, Telecommunications and Multimedia Unit
"The universe is always one step beyond logic." -- Frank Herbert