From ea3f2f13e9ce2024e8865baed4d8f7d4ce2350fe Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADtor=20Santos=20Costa?= <vsc@dcc.fc.up.pt>
Date: Thu, 25 Oct 2012 00:33:02 +0100
Subject: [PATCH] improve python interface

---
 packages/pyswip/python.c  | 414 +++++++++++++++++++++++++++++++-------
 packages/pyswip/python.pl | 103 +++++++++-
 2 files changed, 432 insertions(+), 85 deletions(-)

diff --git a/packages/pyswip/python.c b/packages/pyswip/python.c
index 7bf2d2664..50348b2e7 100644
--- a/packages/pyswip/python.c
+++ b/packages/pyswip/python.c
@@ -8,82 +8,20 @@
 
 static atom_t ATOM_true, ATOM_false;
 
-static foreign_t
-init_python(void)
-{ 
-  Py_Initialize();
+static functor_t FUNCTOR_dollar1,
+  FUNCTOR_pointer1, 
+  FUNCTOR_add2, 
+  FUNCTOR_sub2,
+  FUNCTOR_mul2,
+  FUNCTOR_div2,
+  FUNCTOR_hat2;
 
-  return TRUE;
-}
-
-static foreign_t
-end_python(void)
-{ 
-  Py_Finalize();
-
-  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 *py_Main;
 
 static PyObject *
 term_to_python(term_t t)
 {
+  // Yap_DebugPlWrite(YAP_GetFromSlot(t));        fprintf(stderr, " here I am\n");
   switch (PL_term_type(t)) {
   case PL_VARIABLE:
     return NULL;
@@ -140,6 +78,102 @@ term_to_python(term_t t)
 	  return NULL;
       }
       return out;
+    } else {
+      functor_t fun;
+
+      if (!PL_get_functor(t, &fun))
+	return NULL;
+      if (fun == FUNCTOR_dollar1) {
+	char *s;
+	term_t targ = PL_new_term_ref();
+	if (! PL_get_arg(1, t, targ) )
+	  return NULL;
+	if (!PL_get_atom_chars(targ, &s))
+	  return NULL;
+	/* return __main__,s */
+	return PyObject_GetAttrString(py_Main, s);
+      } else if (fun == FUNCTOR_pointer1) {
+	void *ptr;
+	term_t targ = PL_new_term_ref();
+
+	if (! PL_get_arg(1, t, targ) )
+	  return NULL;
+	if (!PL_get_pointer(targ, &ptr))
+	  return NULL;
+	/* return __main__,s */
+	return (PyObject *)ptr;
+      } else if (fun == FUNCTOR_add2) {
+	term_t targ = PL_new_term_ref();
+	PyObject *lhs, *rhs;
+
+	if (! PL_get_arg(1, t, targ) )
+	  return NULL;
+	lhs = term_to_python(targ);
+	if (!PyNumber_Check(lhs))
+	  return NULL;
+	if (! PL_get_arg(2, t, targ) )
+	  return NULL;
+	rhs = term_to_python(targ);
+	if (!PyNumber_Check(rhs))
+	  return NULL;
+	return PyNumber_Add(lhs, rhs);
+      } else if (fun == FUNCTOR_sub2) {
+	term_t targ = PL_new_term_ref();
+	PyObject *lhs, *rhs;
+
+	if (! PL_get_arg(1, t, targ) )
+	  return NULL;
+	lhs = term_to_python(targ);
+	if (!PyNumber_Check(lhs))
+	  return NULL;
+	if (! PL_get_arg(2, t, targ) )
+	  return NULL;
+	rhs = term_to_python(targ);
+	if (!PyNumber_Check(rhs))
+	  return NULL;
+	return PyNumber_Subtract(lhs, rhs);
+      } else if (fun == FUNCTOR_mul2) {
+	term_t targ = PL_new_term_ref();
+	PyObject *lhs, *rhs;
+
+	if (! PL_get_arg(1, t, targ) )
+	  return NULL;
+	lhs = term_to_python(targ);
+	if (!PyNumber_Check(lhs))
+	  return NULL;
+	if (! PL_get_arg(2, t, targ) )
+	  return NULL;
+	rhs = term_to_python(targ);
+	if (!PyNumber_Check(rhs))
+	  return NULL;
+	return PyNumber_Multiply(lhs, rhs);
+      } else if (fun == FUNCTOR_div2) {
+	term_t targ = PL_new_term_ref();
+	PyObject *lhs, *rhs;
+
+	if (! PL_get_arg(1, t, targ) )
+	  return NULL;
+	lhs = term_to_python(targ);
+	if (!PyNumber_Check(lhs))
+	  return NULL;
+	if (! PL_get_arg(2, t, targ) )
+	  return NULL;
+	rhs = term_to_python(targ);
+	if (!PyNumber_Check(rhs))
+	  return NULL;
+	return PyNumber_Divide(lhs, rhs);
+      } else if (fun == FUNCTOR_hat2) {
+	term_t targ = PL_new_term_ref();
+	PyObject *lhs, *rhs;
+
+	if (! PL_get_arg(1, t, targ) )
+	  return NULL;
+	lhs = term_to_python(targ);
+	if (! PL_get_arg(2, t, targ) )
+	  return NULL;
+	rhs = term_to_python(targ);
+	return PyObject_GetItem(lhs, rhs);
+      }
     }
     return NULL;
   }
@@ -147,14 +181,14 @@ term_to_python(term_t t)
 }
 
 static foreign_t
-output_python_term(PyObject *pVal, term_t t)
+python_to_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) {
+    if (PyObject_IsTrue(pVal)) {
       return PL_unify_atom(t, ATOM_true);
     } else {
       return PL_unify_atom(t, ATOM_false);
@@ -164,32 +198,166 @@ output_python_term(PyObject *pVal, term_t t)
   } else if (PyByteArray_Check(pVal)) {
     atom_t tmp_atom = PL_new_atom(PyByteArray_AsString(pVal));
     return PL_unify_atom(t, tmp_atom);
+  } else if (PyString_Check(pVal)) {
+    atom_t tmp_atom = PL_new_atom(PyString_AsString(pVal));
+    return PL_unify_atom(t, tmp_atom);
   } else if (PyList_Check(pVal)) {
     term_t to = PL_new_term_ref();
     Py_ssize_t i, sz = PyList_GET_SIZE(pVal);
 
     for (i = 0; i < sz; i++) {
       if (!PL_unify_list(t, to, t) ||
-	  !output_python_term(PyList_GetItem(pVal, i), to))
+	  !python_to_term(PyList_GetItem(pVal, i), to))
 	return FALSE;
     }
     return PL_unify_nil(t);
   } else {
+    term_t to = PL_new_term_ref(), t1 = PL_new_term_ref();
+    PL_put_pointer(t1, (void *)pVal);
+    PL_cons_functor(to, FUNCTOR_pointer1, t1);
+    return PL_unify(t, to);
+  }
+}
+
+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;
+  }
+  pModule = PyImport_Import(pName);
+  // PyErr_Print();
+  Py_DECREF(pName);
+  if (pModule == NULL) {
+    return FALSE;
+  }
+  return python_to_term(pModule, mod);
+}
+
+static foreign_t
+python_f(term_t tmod, term_t fname, term_t tf)
+{ 
+  char *s;
+  size_t len;
+  PyObject *pF, *pModule;
+
+  /* if an atom, fetch again */
+  if ( PL_is_atom(tmod) ) {
+    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);
+  } else if (!(pModule = term_to_python(tmod)))
+    return FALSE;
+  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 python_to_term(pF, tf);
+}
+
+static foreign_t
+python_o(term_t tmod, term_t fname, term_t tf)
+{ 
+  char *s;
+  size_t len;
+  PyObject *pO, *pModule;
+
+  pModule = term_to_python(tmod);
+  if ( !PL_get_nchars(fname, &len, &s, CVT_ALL|CVT_EXCEPTION) ) {  
+    return FALSE;
+  }
+  pO = PyObject_GetAttrString(pModule, s);
+  if (pO == NULL) {
+    return FALSE;
+  }
+  return python_to_term(pO, tf);
+}
+
+static foreign_t
+python_set_item(term_t tobj, term_t tpos, term_t titem)
+{ 
+  PyObject *obj, *item, *pos;
+
+  obj = term_to_python(tobj);
+  if (obj == NULL)
+    return FALSE;
+  item = term_to_python(titem);
+  if (item == NULL)
+    return FALSE;
+  pos = term_to_python(tpos);
+  if (pos == NULL)
+    return FALSE;
+  if (PyObject_SetItem(obj, pos,  item) < 0)
+    return FALSE;
+  return TRUE;
+}
+
+static foreign_t
+python_len(term_t tobj, term_t tf)
+{ 
+  Py_ssize_t len;
+  PyObject *o;
+
+  o = term_to_python(tobj);
+  if (o == NULL)
+    return FALSE;
+  len = PyObject_Length(o);
+  return PL_unify_int64(tf, len);
+}
+
+static foreign_t
+python_dir(term_t tobj, term_t tf)
+{ 
+  PyObject *dir;
+  PyObject *o;
+
+  o = term_to_python(tobj);
+  if (o == NULL)
+    return FALSE;
+  dir = PyObject_Dir(o);
+  return python_to_term(dir, tf);
+}
+
+static foreign_t
+python_is(term_t tobj, term_t tf)
+{ 
+  PyObject *o;
+
+  o = term_to_python(tobj);
+  if (!o)
+    return FALSE;
+  return python_to_term(o, tf);
 }
 
 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) ) {
+  pF = term_to_python(tin);
+  if ( pF == NULL ) {
     return FALSE;
   }
   if (! PL_get_name_arity( targs, &aname, &arity) ) {
@@ -208,11 +376,72 @@ python_apply(term_t tin, term_t targs, term_t tf)
   }
   pValue = PyObject_CallObject(pF, pArgs);
   Py_DECREF(pArgs);
-  out =  output_python_term(pValue, tf);
+  if (pValue == NULL)
+    return FALSE;
+  out =  python_to_term(pValue, tf);
   Py_DECREF(pValue);
   return out;
 }
 
+static foreign_t
+python_assign(term_t name, term_t exp)
+{
+  PyObject *e = term_to_python(exp);
+  char *s;
+
+  if (e == NULL)
+    return FALSE;
+  if (!PL_get_atom_chars(name, &s))
+    return FALSE;
+  return PyObject_SetAttrString(py_Main, s, e) >= 0;  
+}
+
+static foreign_t
+python_access(term_t obj, term_t f, term_t out)
+{
+  PyObject *o = term_to_python(obj), *pValue, *pArgs, *pF;
+  atom_t name;
+  char *s;
+  int i, arity;
+  term_t targ = PL_new_term_ref();
+
+  if (o == NULL)
+    return FALSE;
+  if ( PL_is_atom(f) ) {
+    if (!PL_get_atom_chars(f, &s))
+      return FALSE;
+    if ((pValue = PyObject_GetAttrString(o, s)) == NULL)
+      return FALSE;  
+    return python_to_term(pValue, out);
+  }
+  if (! PL_get_name_arity( f, &name, &arity) ) {
+    return FALSE;
+  }
+  s = PL_atom_chars(name);
+  if ((pF = PyObject_GetAttrString(o, s)) < 0)
+    return FALSE;  
+  pArgs = PyTuple_New(arity);
+  for (i = 0 ; i < arity; i++) {
+    PyObject *pArg;
+    if (! PL_get_arg(i+1, f, targ) )
+      return FALSE;
+    pArg = term_to_python(targ);
+    if (pArg == NULL)
+      return FALSE;
+    /* pArg reference stolen here: */
+    PyTuple_SetItem(pArgs, i,  pArg);
+  }
+  pValue = PyObject_CallObject(pF, pArgs);
+  if (pValue == NULL) {
+    Py_DECREF(pArgs);
+    Py_DECREF(pF);
+    return FALSE;
+  }
+  Py_DECREF(pArgs);
+  Py_DECREF(pF);
+  return python_to_term(o, out);
+}
+
 static foreign_t
 python_run_command(term_t cmd)
 { 
@@ -227,6 +456,23 @@ python_run_command(term_t cmd)
   return FALSE;
 }
 
+static foreign_t
+init_python(void)
+{ 
+  Py_Initialize();
+  py_Main =  PyImport_AddModule("__main__");
+
+  return TRUE;
+}
+
+static foreign_t
+end_python(void)
+{ 
+  Py_Finalize();
+
+  return TRUE;
+}
+
 install_t install_python(void);
 
 install_t
@@ -236,12 +482,26 @@ install_python(void)
   // FUNCTOR_boolop1 = PL_new_functor(PL_new_atom("@"), 1);
   ATOM_true  = PL_new_atom("true");
   ATOM_false = PL_new_atom("false");
+  FUNCTOR_dollar1 = PL_new_functor(PL_new_atom("$"), 1);
+  FUNCTOR_pointer1 = PL_new_functor(PL_new_atom("__obj__"), 1);
+  FUNCTOR_add2 = PL_new_functor(PL_new_atom("+"), 2);
+  FUNCTOR_sub2 = PL_new_functor(PL_new_atom("-"), 2);
+  FUNCTOR_mul2 = PL_new_functor(PL_new_atom("*"), 2);
+  FUNCTOR_div2 = PL_new_functor(PL_new_atom("/"), 2);
+  FUNCTOR_hat2 = PL_new_functor(PL_new_atom("^"), 2);
 
   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_o",	  3, python_o,       0);
+  PL_register_foreign("python_len",	  2, python_len,       0);
+  PL_register_foreign("python_is",	  2, python_is,       0);
+  PL_register_foreign("python_dir",	  2, python_dir,       0);
   PL_register_foreign("python_apply",	  3, python_apply,       0);
+  PL_register_foreign("python_access",	  3, python_access,       0);
+  PL_register_foreign("python_assign",	  2, python_assign,       0);
+  PL_register_foreign("python_set_item",  3, python_set_item,       0);
   PL_register_foreign("python_run_command",	  1, python_run_command,       0);
 }
 
diff --git a/packages/pyswip/python.pl b/packages/pyswip/python.pl
index 60b0ba9ce..1145f23e1 100644
--- a/packages/pyswip/python.pl
+++ b/packages/pyswip/python.pl
@@ -27,31 +27,118 @@ A C-based  Prolog interface to python.
      init_python/0,
      end_python/0,
      python_command/1,
-     python/3
+     python_assign/3,
+     python/2,
+     op(100,fy,$),
+     op(950,fy,:=),
+     op(950,yfx,:=),
+     (:=)/2,
+     (:=)/1
      ]).
 
+
+/************************************************************************************************************
+
+Python interface
+
+Data types are
+
+     Python		Prolog
+     string             atoms
+     numbers		numbers
+     lists		lists
+     generic objs	__pointer__(Address)
+
+$(var) refers to the attribute __main__.var
+
+*************************************************************************************************************/
+
 :- use_module(library(shlib)).
 :- use_module(library(lists)).
 :- use_module(library(apply_macros)).
 :- use_module(library(charsio)).
 
-python(Module:Function, IArgs, OArg) :-
-	python_import(Module, MRef),
-	python_f(MRef, Function, FRef),
-	Args =.. [c|IArgs],
-	python_apply(FRef, Args, OArg).
+:- dynamic python_mref_cache/2.
+
+:= F :- python(F,_).
+
+V := F :- var(V), !, python(F,V).
+'$'(V) := F :- atom(V), !, python(F,F1), python_assign(V, F1).
+A^Key := F :- python(F,F1), python_set_item(A, Key, F1).
+
+python_do_import(Module, MRef) :-
+	python_mref_cache(Module, MRef), !.
+python_do_import(Module, MRef) :-
+        python_import(Module, MRef),
+	assert( python_mref_cache(Module, MRef) ).
+
+python_eval_term(Object:len, OArg) :- !,
+	python_len(Object, OArg).	
+python_eval_term(Module:Object:len, OArg) :- !,
+	python_do_import(Module, MRef),
+	python_o(MRef, Function, ORef),
+	python_len(ORef, OArg).	
+python_eval_term(Object:dir, OArg) :- !,
+	python_dir(Object, OArg).	
+python_eval_term(Module:Object:dir, OArg) :- !,
+	python_do_import(Module, MRef),
+	python_o(MRef, Function, ORef),
+	python_dir(ORef, OArg).	
+python_eval_term(Module:Object:Field, OArg) :-
+	atom(Module),
+	atom(Object), !,
+	python_do_import(Module, MRef),
+	python_o(MRef, Function, ORef),
+	python_access(ORef, Field, OArg).
+python_eval_term(Module:Function, OArg) :-
+	atom(Module), !,
+	python_do_import(Module, MRef),
+	functor(Function, F, _),
+	python_f(MRef, F, FRef),
+	python_apply(FRef, Function, OArg).
+python_eval_term(Obj:Field, OArg) :-
+	python_access(Obj, Field, OArg).
+
+python(Obj, Out) :-
+	 python_eval_term(Obj, Out), !.
+python(Obj, OArg) :-
+	python_do_is(Obj, Obj1),
+	python_is(Obj1, OArg).
+
+python_do_is(A+B, NA+NB) :- !,
+	python_do_is(A, NA),
+	python_do_is(B, NB).
+python_do_is(A-B, NA-NB) :- !,
+	python_do_is(A, NA),
+	python_do_is(B, NB).
+python_do_is(A*B, NA*NB) :- !,
+	python_do_is(A, NA),
+	python_do_is(B, NB).
+python_do_is(A/B, NA/NB) :- !,
+	python_do_is(A, NA),
+	python_do_is(B, NB).
+python_do_is(A, NA) :-
+	python_eval_term(A, NA), !.
+python_do_is(A, A).
 
 python_command(Cmd) :-
-    python_run_command(Cmd).
+       python_run_command(Cmd).
 
 start_python :-
 	use_foreign_library(foreign(python)),
 	init_python,
-	python_command('import sys'),
+	python_command('import sys').
+
+add_cwd_to_python :-
 	unix(getcwd(Dir)),
 	atom_concat(['sys.path.append(\"',Dir,'\")'], Command),
 	python_command(Command).
 	% done	
 
+python_assign(Name, Exp, '$'(Name)) :-
+	python_assign(Name, Exp).
 
 :- initialization(start_python, now).
+
+:- initialization(add_cwd_to_python).
+