Where can I learn more about PMCode?
Regards,
Luis
On Sat, Feb 09, 2013 at 01:35:56PM -0600, David Mertens wrote:
> sorry, that last bit was incomplete. Somehow sit send without meaning to.
> Now, continuing...
>
> pp_def('some_func' =>
> Pars => 'input_piddle(); [o] output_piddle()',
> OtherPars => 'SV * output_scalar',
> Code => q{
> /* Code goes here; manipulate the output SV with Perl XS functions
> */
> },
> PMCode => q{
> sub some_func {
> my ($input_piddle) = @_;
> # You should see if they also passed in a pre-constructed
> output piddle,
> # but I'll ignore that for now
> my $output_piddle = $intput_piddle->zeroes;
> my $output_scalar;
>
> # Notice the name of the actual XS-defined function is a little
> name-mangled
> _some_func_int($input_piddle, $output_piddle, $output_scalar);
> return $output_piddle, $output_scalar;
> }
> },
> );
>
>
> Commentary to follow...
>
>
> On Sat, Feb 9, 2013 at 1:32 PM, David Mertens <[email protected]>wrote:
>
> > John -
> >
> > There is more than one way to do it. :-)
> >
> > First, you could simply use the OtherPars section, passing an SV*, and
> > modify the functions calling convention. For example, you can include a "my
> > $output" in your function call and get it out on the other side:
> >
> > pp_def('some_func' =>
> > Pars => 'input_piddle(); [o] output_piddle()',
> > OtherPars => 'SV * output_scalar',
> > Code => q{
> > /* Code goes here; manipulate the output SV with Perl XS functions
> > */
> > },
> > );
> >
> > You would then call this function as
> >
> > $output_piddle = $input_piddle->some_func(my $output_scalar);
> >
> > The next option is to use the PMCode key. Beware, however, this does not
> > work with Inline::Pdlpp, only with compiled pd files. The PMCode section
> > specifies perl code that is meant to wrap the function you define. It looks
> > something like this:
> >
> > pp_def('some_func' =>
> > Pars => 'input_piddle(); [o] output_piddle()',
> > OtherPars => 'SV * output_scalar',
> > Code => q{
> > /* Code goes here; manipulate the output SV with Perl XS functions
> > */
> > },
> > PMCode => q{
> > sub some_func {
> > my ($input_piddle) = @_;
> >
> > }
> > },
> > );
> >
> >
> >
> > On Sat, Feb 9, 2013 at 11:54 AM, John Lapeyre
> > <[email protected]>wrote:
> >
> >> Hello,
> >>
> >> Does anyone know how to write a call to `pp_def' that somehow returns,
> >> or updates, scalar values ? I know that with `OtherPars' it is easy
> >> to specify that a scalar is to be passed as input. For output, do I
> >> have to somehow use the normal C api to perl to get at the contents of
> >> an SV?
> >>
> >> For instance, I might want to take piddles and or scalars as input and
> >> have scalars and possibly piddle as output. A clumsy solution is to
> >> pass a piddle of length 1, where I really want a scalar, in the `Code'
> >> string, and then write a wrapper function in perl to extract the
> >> scalar from the auxiallry piddle.
> >>
> >> A related question: With `GenericTypes' and the template mechanism
> >> `$T( ...', I can automatically generate interfaces for several
> >> types of piddles. Is it possible to somehow use this template with
> >> `OtherPars' ? In particular, I want to define a function via
> >> pp_def that takes a piddle and a scalar as arguments. I want the
> >> two arguments to be of the same type. For example, both integers,
> >> both doubles, etc.
> >>
> >> Thank you!
> >>
> >> John
> >>
> >>
> >> ______________________________**_________________
> >> Perldl mailing list
> >> [email protected]
> >> http://mailman.jach.hawaii.**edu/mailman/listinfo/perldl<http://mailman.jach.hawaii.edu/mailman/listinfo/perldl>
> >>
> >
> >
> >
> > --
> > "Debugging is twice as hard as writing the code in the first place.
> > Therefore, if you write the code as cleverly as possible, you are,
> > by definition, not smart enough to debug it." -- Brian Kernighan
> >
>
>
>
> --
> "Debugging is twice as hard as writing the code in the first place.
> Therefore, if you write the code as cleverly as possible, you are,
> by definition, not smart enough to debug it." -- Brian Kernighan
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o
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