improve interface

packages/pyswip/python.c

@@ -1,8 +1,13 @@
 #include <SWI-Stream.h>
 #include <SWI-Prolog.h>
+#ifdef HAVE_STAT
+#undef HAVE_STAT
+#endif
 #include <Python.h>
 #include <assert.h>
 
+static atom_t ATOM_true, ATOM_false;
+
 static foreign_t
 init_python(void)
 { 
@@ -18,6 +23,162 @@ end_python(void)
   return TRUE;
 }
 
+static int
+python_import(term_t mname, term_t mod)
+{ 
+  char *s;
+  size_t len;
+  PyObject *pName, *pModule;
+
+  if ( !PL_get_nchars(mname, &len, &s, CVT_ALL|CVT_EXCEPTION) ) {  
+    return FALSE;
+  }
+  pName = PyString_FromString(s);
+  if (pName == NULL) {
+    return FALSE;
+  }
+PyRun_SimpleString("import sys");
+PyRun_SimpleString("sys.path.append(\"/Users/vsc/Yap/bins/osx/packages/pyswip\")");
+//PyRun_SimpleString("import multiply");
+  pModule = PyImport_Import(pName);
+  PyErr_Print();
+  Py_DECREF(pName);
+  if (pModule == NULL) {
+    return FALSE;
+  }
+  return PL_unify_pointer(mod, (void *)pModule);
+}
+
+static foreign_t
+python_f(term_t tmod, term_t fname, term_t tf)
+{ 
+  char *s;
+  size_t len;
+  PyObject *pF, *pModule;
+  void **mp = (void *)&pModule;
+
+  if ( !PL_get_pointer(tmod, mp) ) {
+    PyObject *pName;
+
+    if ( !PL_get_nchars(fname, &len, &s, CVT_ALL|CVT_EXCEPTION) ) {  
+      return FALSE;
+    }
+    pName = PyString_FromString(s);
+    if (pName == NULL) {
+      return FALSE;
+    }
+    pModule = PyImport_Import(pName);
+  }
+  if ( !PL_get_nchars(fname, &len, &s, CVT_ALL|CVT_EXCEPTION) ) {  
+    return FALSE;
+  }
+  pF = PyObject_GetAttrString(pModule, s);
+  if (pF == NULL || ! PyCallable_Check(pF)) {
+    return FALSE;
+  }
+  return PL_unify_pointer(tf, (void *)pF);
+}
+
+static PyObject *
+term_to_python(term_t t)
+{
+  switch (PL_term_type(t)) {
+  case PL_VARIABLE:
+    return NULL;
+  case PL_ATOM:
+    {
+      char *s;
+      
+      if (!PL_get_atom_chars(t, &s))
+	return NULL;
+      return PyByteArray_FromStringAndSize(s, strlen(s) );
+    }
+  case PL_INTEGER:
+    {
+      int64_t j;
+      if (!PL_get_int64_ex(t, &j))
+	return NULL;
+      return PyInt_FromLong(j);
+    }
+  case PL_STRING:
+    {
+      char *s;
+      size_t len;
+
+      if (!PL_get_string_chars(t, &s, &len))
+	return NULL;
+      return PyByteArray_FromStringAndSize(s, len );
+    }
+  case PL_FLOAT:
+    {
+      double fl;
+      if (!PL_get_float(t, &fl))
+	return NULL;
+      return PyFloat_FromDouble( fl );
+    }
+  case PL_TERM:
+    return NULL;
+  }
+  return NULL;
+}
+
+static foreign_t
+output_python_term(PyObject *pVal, term_t t)
+{
+  if (PyLong_Check(pVal)) {
+    return PL_unify_int64(t, PyLong_AsLong(pVal));
+  } else if (PyInt_Check(pVal)) {
+    return PL_unify_int64(t, PyInt_AsLong(pVal));
+  } else if (PyBool_Check(pVal)) {
+    if (pVal == Py_True) {
+      return PL_unify_atom(t, ATOM_true);
+    } else {
+      return PL_unify_atom(t, ATOM_false);
+    }
+  } else if (PyFloat_Check(pVal)) {
+    return PL_unify_float(t, PyFloat_AsDouble(pVal));
+  } else if (PyByteArray_Check(pVal)) {
+    atom_t tmp_atom = PL_new_atom(PyByteArray_AsString(pVal));
+    return PL_unify_atom(t, tmp_atom);
+  } else {
+    return FALSE;
+  }
+}
+
+static foreign_t
+python_apply(term_t tin, term_t targs, term_t tf)
+{ 
+  PyObject *pF, *pArgs, *pValue;
+  void **mpf = (void *)&pF;
+  int i, arity;
+  atom_t aname;
+  foreign_t out;
+  term_t targ = PL_new_term_ref();
+
+  if ( !PL_get_pointer(tin, mpf) ) {
+    return FALSE;
+  }
+  if (! PL_get_name_arity( targs, &aname, &arity) ) {
+    return FALSE;
+  }
+  pArgs = PyTuple_New(arity);
+  for (i = 0 ; i < arity; i++) {
+    PyObject *pArg;
+    if (! PL_get_arg(i+1, targs, targ) )
+      return FALSE;
+    pArg = term_to_python(targ);
+    if (pArg == NULL)
+      return NULL;
+    /* pArg reference stolen here: */
+    PyTuple_SetItem(pArgs, i,  pArg);
+  }
+  pValue = PyObject_CallObject(pF, pArgs);
+  Py_DECREF(pArgs);
+  out =  output_python_term(pValue, tf);
+  Py_DECREF(pValue);
+  return out;
+}
+
 static foreign_t
 python_run_command(term_t cmd)
 { 
@@ -39,10 +200,14 @@ install_python(void)
 { // FUNCTOR_dot2 = PL_new_functor(PL_new_atom("."), 2);
   // FUNCTOR_equal2 = PL_new_functor(PL_new_atom("="), 2);
   // FUNCTOR_boolop1 = PL_new_functor(PL_new_atom("@"), 1);
-  // ATOM_true  = PL_new_atom("true");
+  ATOM_true  = PL_new_atom("true");
-  // ATOM_false = PL_new_atom("false");
+  ATOM_false = PL_new_atom("false");
 
   PL_register_foreign("init_python",	  0, init_python,      0);
   PL_register_foreign("end_python",	  0, end_python,       0);
+  PL_register_foreign("python_import",	  2, python_import,       0);
+  PL_register_foreign("python_f",	  3, python_f,       0);
+  PL_register_foreign("python_apply",	  3, python_apply,       0);
   PL_register_foreign("python_run_command",	  1, python_run_command,       0);
 }
+

packages/pyswip/python.pl

@@ -1,20 +1,33 @@
 %%% -*- Mode: Prolog; -*-
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-%    Author:        Nicos Angelopoulos, Vitor Santos Costa, Jan Wielemaker
+%    Author:        Vitor Santos Costa
-%    E-mail:        Nicos Angelopoulos <nicos@gmx.co.uk>
+%    E-mail:        vsc@dcc.fc.up.pt
-%    Copyright (C): Nicos Angelopoulos, Universidade do Porto, VU University Amsterdam
+%    Copyright (C): Universidade do Porto
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %
-%  This file is part of r..eal
+%  This file is part of the YAP Python Interface
 %  distributed according to Perl Artistic License
 %  check LICENSE file for distribution license
 %
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
+/** <module> python
+
+A C-based  Prolog interface to python.
+
+@author		Vitor Santos Costa
+@version	0:0:5, 2012/10/8
+@license	Perl Artistic License
+
+*/
+
+%%%
+
 :- module(python, [
      init_python/0,
      end_python/0,
-     python_command/1
+     python_command/1,
+     python/3
      ]).
 
 :- use_module(library(shlib)).
@@ -22,18 +35,11 @@
 :- use_module(library(apply_macros)).
 :- use_module(library(charsio)).
 
-/** <module> python
+python(Module:Function, IArgs, OArg) :-
-
+	python_import(Module, MRef),
-A C-based  Prolog interface to python.
+	python_f(MRef, Function, FRef),
-
+	Args =.. [c|IArgs],
-
+	python_apply(FRef, Args, OArg).
-@author		Vitor Santos Costa
-@version	0:0:5, 2012/09/12
-@license	Perl Artistic License
-
-*/
-
-%%%
 
 python_command(Cmd) :-
     python_run_command(Cmd).