Swig and pointers

[Java and Swing]

I've tried sending a email to the swig mailing list 3 times...but it
never seems to get it...not sure what is going on, still looking into
it. Until then...

I now have a C function such as...

int doIt(char *a, MY_DIGIT **digit) {
...
}

so I am trying to figure out how to pass in that "digit" pointer.

My SWIG interface file looks like...

extern int doIt(char *a, MY_DIGIT **digit);
%include cpointer.i
%pointer_functi ons(MY_DIGIT, md_prt);
%typemap(in) (char *a, MY_DIGIT **argv) {
/* Check if is a list */
if (PyList_Check($ input)) {
int i;
$1 = PyList_Size($in put);
$2 = (MY_DIGIT **) malloc(($1+1)*s izeof(long *));
for (i = 0; i < $1; i++) {
PyObject *o = PyList_GetItem( $input,i);
if (PyString_Check (o))
$2[i] = PyString_AsStri ng(PyList_GetIt em($input,i));
else {
PyErr_SetString (PyExc_TypeErro r,"list must contain strings");
free($2);
return NULL;
}
}
$2[i] = 0;
} else {
PyErr_SetString (PyExc_TypeErro r,"not a list");
return NULL;
}
}

%typemap(freear g) (char *a, MY_DIGIT **argv) {
free((MY_DIGIT *) $2);
}


...from Python I am trying
[color=blue][color=green]
>> ptr = []
>> doIt("blah", ptr)[/color][/color]

I thought this was the correct approach as described here:

http://www.swig.org/Doc1.3/SWIGDocumentation.html#Python_nn59

However, python comes back and says "TypeError: argument number 2: a
'MY_DIGIT **' is expected, 'list([])' is received"

...any ideas? Thanks for all the help. The python community has been
great.

[Miki Tebeka]

Re: Swig and pointers

Hello Java,
[color=blue]
> ...
> extern int doIt(char *a, MY_DIGIT **digit);
> %include cpointer.i
> %pointer_functi ons(MY_DIGIT, md_prt);[/color]
Don't you mean md_ptr?
[color=blue]
> %typemap(in) (char *a, MY_DIGIT **argv) {
> /* Check if is a list */
> if (PyList_Check($ input)) {
> int i;
> $1 = PyList_Size($in put);
> $2 = (MY_DIGIT **) malloc(($1+1)*s izeof(long *));
> for (i = 0; i < $1; i++) {
> PyObject *o = PyList_GetItem( $input,i);
> if (PyString_Check (o))
> $2[i] = PyString_AsStri ng(PyList_GetIt em($input,i));
> else {
> PyErr_SetString (PyExc_TypeErro r,"list must contain strings");
> free($2);
> return NULL;
> }
> }
> $2[i] = 0;
> } else {
> PyErr_SetString (PyExc_TypeErro r,"not a list");
> return NULL;
> }
> }
>
> %typemap(freear g) (char *a, MY_DIGIT **argv) {
> free((MY_DIGIT *) $2);
> }
>
>
> ..from Python I am trying
> [color=green][color=darkred]
> >> ptr = []
> >> doIt("blah", ptr)[/color][/color]
>
> I thought this was the correct approach as described here:
> http://www.swig.org/Doc1.3/SWIGDocum...ml#Python_nn59
>
> However, python comes back and says "TypeError: argument number 2: a
> 'MY_DIGIT **' is expected, 'list([])' is received"
>
> ..any ideas? [/color]
Didn't check it but from http://www.swig.org/Doc1.3/Library.html it looks
like you need to do:
ptr = new_md_prt()

HTH.
--
------------------------------------------------------------------------
Miki Tebeka <mtebeka@qualco mm.com>

http://tebeka.bizhat.com

The only difference between children and adults is the price of the toys

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.1 (Cygwin)

iD8DBQFDRPq78jA dENsUuJsRAiwfAJ 43iL7y8B1PNSgzu YVte+40UuDI5wCg q/4K
vSRoo7AzIRZewYt 1SYxMuXU=
=gLFG
-----END PGP SIGNATURE-----

[Java and Swing]

Re: Swig and pointers

im sorry, why would it be md_ptr? what is md_ptr?

i tried..
%include cpointer.i
%pointer_functi ons(MY_DIGIT, digit_ptr)

ptr = new_digit_ptr()
doIt("a message", ptr)
....doesnt work..still needs a DIGIT **

[Java and Swing]

Re: Swig and pointers

(reposting, i was just told how I should properly reply via
groups.google.c om)

im sorry, why would it be md_ptr? what is md_ptr?

i tried..
%include cpointer.i
%pointer_functi ons(MY_DIGIT, digit_ptr)

ptr = new_digit_ptr()
doIt("a message", ptr)
....doesnt work..still needs a DIGIT **


Miki Tebeka wrote:[color=blue]
> Hello Java,
>[color=green]
> > ...
> > extern int doIt(char *a, MY_DIGIT **digit);
> > %include cpointer.i
> > %pointer_functi ons(MY_DIGIT, md_prt);[/color]
> Don't you mean md_ptr?
>[color=green]
> > %typemap(in) (char *a, MY_DIGIT **argv) {
> > /* Check if is a list */
> > if (PyList_Check($ input)) {
> > int i;
> > $1 = PyList_Size($in put);
> > $2 = (MY_DIGIT **) malloc(($1+1)*s izeof(long *));
> > for (i = 0; i < $1; i++) {
> > PyObject *o = PyList_GetItem( $input,i);
> > if (PyString_Check (o))
> > $2[i] = PyString_AsStri ng(PyList_GetIt em($input,i));
> > else {
> > PyErr_SetString (PyExc_TypeErro r,"list must contain strings");
> > free($2);
> > return NULL;
> > }
> > }
> > $2[i] = 0;
> > } else {
> > PyErr_SetString (PyExc_TypeErro r,"not a list");
> > return NULL;
> > }
> > }
> >
> > %typemap(freear g) (char *a, MY_DIGIT **argv) {
> > free((MY_DIGIT *) $2);
> > }
> >
> >
> > ..from Python I am trying
> >[color=darkred]
> > >> ptr = []
> > >> doIt("blah", ptr)[/color]
> >
> > I thought this was the correct approach as described here:
> > http://www.swig.org/Doc1.3/SWIGDocum...ml#Python_nn59
> >
> > However, python comes back and says "TypeError: argument number 2: a
> > 'MY_DIGIT **' is expected, 'list([])' is received"
> >
> > ..any ideas?[/color]
> Didn't check it but from http://www.swig.org/Doc1.3/Library.html it looks
> like you need to do:
> ptr = new_md_prt()
>
> HTH.
> --
> ------------------------------------------------------------------------
> Miki Tebeka <mtebeka@qualco mm.com>
> http://tebeka.bizhat.com
> The only difference between children and adults is the price of the toys[/color]