How to let my XS module interact with existing XS module?

llancet has asked for the wisdom of the Perl Monks concerning the following question:

Hi monks!

I'm going to write some kind of drawing library using Cairo, and I want to create a Perl wrapper for my lib. It would have some method functions like this:

class MyPage
{
    MyPage(cairo_t* context);
}
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In which, functions of my code have arguments of Cairo's type. I know there's already a Cairo wrapper for perl in CPAN, so I want to have my wrapped code can work like this:

use Cairo;
use MyLib;

......
my $context = Cairo::Context->create(...);
my $page = MyLib::MyPage->new($context);
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However, to achieve this, the XS code of mine must have the knowledge of how Cairo's XS code do the wrap. As I'm not experienced on XS, I need some suggests on it. Thanks for a lot!!

In addition, I noticed that SWIG is another choice for wrapper creation. However Cairo is wrapped using XS, so maybe I have to use XS too?

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Re: How to let my XS module interact with existing XS module? by llancet (Friar) on Aug 16, 2013 at 02:07 UTC
In addition, I failed to find how Perl Cairo module wraps cairo_t. In its typemap, there's no entry for it: `# content of "cairo-perl.typemap" const char * T_PV char_utf8 * T_PV_UTF8 const char_utf8 * T_PV_UTF8 cairo_bool_t T_UV cairo_font_extents_t * T_CAIRO_FONT_EXTENTS cairo_text_extents_t * T_CAIRO_TEXT_EXTENTS cairo_glyph_t * T_CAIRO_GLYPH cairo_text_cluster_t * T_CAIRO_TEXT_CLUSTER cairo_path_t * T_CAIRO_PATH FT_Face T_FT_FACE` [download]	[reply] [d/l]
Re^2: How to let my XS module interact with existing XS module? (Cairo-1.061\blib\arch\Cairo\Install\cairo-perl-auto.typemap) by Anonymous Monk on Aug 16, 2013 at 07:33 UTC
`Cairo-1.061\blib\arch\Cairo\Install\cairo-perl-auto.typemap 7:cairo_t * T_CAIROPERL_GENERIC_WRAPPER 35:const cairo_t * T_CAIROPERL_GENERIC_WRAPPER` [download]	[reply] [d/l]
Re: How to let my XS module interact with existing XS module? by llancet (Friar) on Aug 16, 2013 at 07:18 UTC
I did some study on the Perl's ecology of XS system. It seems an typemap can be shared only if its author made it using ExtUtils::Typemap as a module. I also found that Cairo's main typemap is auto-generated at pre-compilation stage of the module. So it seems I cannot use the existing Cairo wrapper to cooperate with the wrapper of my lib. I would consider a re-design of my API to allow it working without using Cairo's types as function parameter, like this: `typedef enum { SURFACE_PDF, SURFACE_SVG, SURFACE_IMAGE, SURFACE_PS } SurfaceType; class MyPage { MyPage(SurfaceType type); };` [download]	[reply] [d/l]
Re^2: How to let my XS module interact with existing XS module? (ExtUtils::Depends) by Anonymous Monk on Aug 16, 2013 at 07:44 UTC
It seems an typemap can be shared only if its author made it using ExtUtils::Typemap as a module Never heard of that. Its a file, if its installed, and you can find it, you can include it https://metacpan.org/module/ExtUtils::MakeMaker#TYPEMAPS `Pango-1.221\blib\arch\Pango\Install\Files.pm Pango-1.221\blib\arch\Pango\Install\pango-perl-autogen.h Pango-1.221\blib\arch\Pango\Install\pango-perl-versions.h Pango-1.221\blib\arch\Pango\Install\pango-perl.h Pango-1.221\blib\arch\Pango\Install\pango-perl.typemap Pango-1.221\blib\arch\Pango\Install\pango.typemap` [download] Gtk2::Install::Files Read more... (2 kB) Seems Gtk2::Install::Files is generated by ExtUtils::Depends, so just use ExtUtils::Depends in Makefile.PL and ... less work for you :)	[reply] [d/l] [select]