Re: [Help-glpk] Patch for GLPK 4.35 to support SWIG

[Kelly Westbrooks]

Hi Nigel,

If you are the original author of the SWIG interface definition file from GLPK, 
then you have my many thanks -- being able to call GLPK functions from within 
Ruby and Java has saved me countless hours in my PhD studies!

If the only action that is taken is to remove the redundant #defines from 
glpk.h, then that would be enough. I was only requesting that the lines be 
removed to save myself some headache when I regenerate my own language bindings 
each time I update my GLPK codebase. It is good to know that other users suffer 
from this problem -- if more people request the change, then perhaps it has a 
better chance of happening.

--Kelly


--- On Mon, 2/2/09, Nigel Galloway <address@hidden> wrote:

> From: Nigel Galloway <address@hidden>
> Subject: Re: [Help-glpk] Patch for GLPK 4.35 to support SWIG
> To: "Kelly Westbrooks" <address@hidden>
> Cc: address@hidden
> Date: Monday, February 2, 2009, 9:26 AM
> 
> -----Inline Attachment Follows-----
> 
> Details of projects using swig can
> be found at:
>     http://www.swig.org/projects.html
> 
> It is not necessary to use the same file in the #include
> statement 
> as in the %include statement. Therefore it is not necessary
> to 
> modify glpk.h. I asked for these to be removed 18 months
> ago when 
> there were only 3. If Andrew takes them out for you, when
> he didn't 
> for me, I shall have to consider him sexist. It is better
> to use 
> your own file as there is a lot of other rubbish that can
> be 
> removed.
> 
> Attached are some files demonstrating using SWIG with
> glpk_4.35.
> 
> test.rb is the example of using Glpk's new graph feature
> (page 159 
> glpk.pdf) written in ruby.
> 
> GLPK.swig is similar to the Swig input files previously
> described. Two lines:
>    %include "cmalloc.i"
>    %sizeof(double)
> are added. This causes a constant NigelzGLPK::Sizeof_double
> to be 
> available to test.rb (if required). I didn't use it (it's
> 8), I'm 
> hoping the interfaces to the graph routines improve soon.
> 
> glpkSWIG.h is similar to glpk.h as distributed. Terrible
> coding 
> practice in Glpk uses #DEFINE of the same name more than
> once, 
> fortunately to the same value. Previously there were 3, now
> there 
> are 5. These are commented out, SWIG thinks they're bad, I
> think 
> they're bad, they're out.
> 
> diff.out documents the difference between glpk.h and
> glpkSWIG.h.
> 
> sample.min is the data file described in glpk.pdf (page
> 156).
> 
> mincost.lp is the file created by running 'ruby test.rb'.
> 
> GLPK_wrap.cxx is the output file created by:
>    swig -c++ -ruby GLPK.swig
> if you want to try without installing swig use this file:
>    g++ -c GLPK_wrap.cxx
> -I/usr/lib/ruby/1.8/i486-linux/ -I 
> /opt/glpk-4.35/include/
> then:
>    g++ -shared GLPK_wrap.o -L
> /opt/glpk-4.35/lib/ -lglpk -o nigelzGLPK.so
> 
> This is the minimum required to make Glpk available, using
> SWIG, in 
> a number of languages including Ruby, Java, C#, Lua, and
> Python.
> 
> Ruby already has a project using SWIG to interface Glpk and
> Ruby called rGLPK.
> 
> Individuals may wish to comment out a lot more of
> glpkSWIG.h, 
> however it would be better if a lot of the rubbish was
> removed from 
> glpk.h to another header, say GLPKdirtywashing.h.
> 
> 
> 
> > ----- Original Message -----
> > From: "Kelly Westbrooks" <address@hidden>
> > To: "Andrew Makhorin" <address@hidden>
> > Cc: address@hidden
> > Subject: Re: [Help-glpk] Patch for GLPK 4.35 to
> support SWIG
> > Date: Fri, 30 Jan 2009 08:43:45 -0800 (PST)
> >
> >
> > > Could you point out a GNU package (library)
> similar to glpk which
> > > provides swig support? The GNU maintainer
> documentation says nothing
> > > about such feature.
> >
> > Actually, I can't provide you an example. Math::GSL is
> a 
> > SWIG-generated Perl interface to the GSL library, but
> it looks 
> > like its maintained in a separate repository.
> >
> > > Is it sufficient to have glpk.h and libglpk to
> build a wrapper with
> > > swig?
> >
> > I haven't tried, but i'm fairly sure it's possible. It
> would 
> > burden the user with having to deploy 2 libraries
> (libglpk and 
> > the wrapper library) instead of one, which might be
> undesirable 
> > for some people. But then, there are good arguments
> for keeping 
> > them separate as well.
> >
> > > Which lines in glpk.h cause problems? I did not
> find that
> > > in your patch file.
> >
> > Lines 152-156:
> >
> > #define GLP_MSG_OFF        0 
> /* no output */
> > #define GLP_MSG_ERR        1 
> /* warning and error messages only */
> > #define GLP_MSG_ON     
>    2  /* normal output */
> > #define GLP_MSG_ALL        3 
> /* full output */
> > #define GLP_MSG_DBG        4 
> /* debug output */
> >
> > These lines are redundant (they are identical to lines
> 115-119) 
> > and i'm pretty sure they can be safely removed without
> breaking 
> > anything. When you try to run SWIG against glpk.h,
> SWIG complains 
> > about these lines.
> >
> > I can appreciate you hesitation about including the
> SWIG 
> > interface file in the GLPK source tree - it would be
> one more 
> > thing to maintain and it is peripheral to the
> fundamental purpose 
> > of the library. I know that i'm not the first person
> that has had 
> > a desire use GLPK from a language other than C - in
> fact, I stole 
> > the interface file from here:
> > http://www.nabble.com/Re:-GLPK-and-Java-using-SWIG-tc10910553.html
> > and made a few changes to it to suit my own tastes.
> >
> > I guess that i'm suggesting that by including the
> glpk.i 
> > interface file in the GLPK source tree, it might
> encourage others 
> > to use the SWIG-generated wrappers as a foundation for
> writing 
> > clean interfaces to GLPK in other languages. As it
> currently 
> > stands, someone that wants to do this has to jump
> through a few 
> > hoops (write the SWIG interface file glpk.i, make
> changes to 
> > glpk.h, etc).
> >
> > --Kelly
> >
> >
> >
> >
> >
> > _______________________________________________
> > Help-glpk mailing list
> > address@hidden
> > http://lists.gnu.org/mailman/listinfo/help-glpk
> 
> >
> 
> 
> -- 
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