From b9de5c36c0a62048abee457d89b994ebbeb7acf7 Mon Sep 17 00:00:00 2001
From: "jordi.saludes" <jordi.saludes@upc.edu>
Date: Tue, 27 Jul 2010 07:50:48 +0000
Subject: [PATCH] Added inferExpr to py-bindings.

---
 contrib/py-bindings/PyGF.hsc   |  7 +++++++
 contrib/py-bindings/gfmodule.c | 28 ++++++++++++++++++++++++----
 contrib/py-bindings/test.py    | 12 ++++++++++++
 3 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/contrib/py-bindings/PyGF.hsc b/contrib/py-bindings/PyGF.hsc
index 6ac5b05d7..7b9991f3e 100644
--- a/contrib/py-bindings/PyGF.hsc
+++ b/contrib/py-bindings/PyGF.hsc
@@ -219,6 +219,13 @@ gf_unstr pexp = do
         Just s -> newCString s
         _      -> return nullPtr
 
+foreign export ccall gf_inferexpr :: Ptr PGF -> Ptr Expr -> Ptr Type -> IO ()
+gf_inferexpr ppgf pexp ptype = do
+    pgf <- peek ppgf
+    exp <- peek pexp
+    let Right (_,t) = inferExpr pgf exp
+    poke ptype t
+
 foreign import ccall "newLang" pyLang :: IO (Ptr Language) 
 foreign import ccall "newTree" pyTree :: IO (Ptr Tree) 
 foreign import ccall "newCId" pyCId :: IO (Ptr CId) 
diff --git a/contrib/py-bindings/gfmodule.c b/contrib/py-bindings/gfmodule.c
index 06896b9ba..8491f2eb5 100644
--- a/contrib/py-bindings/gfmodule.c
+++ b/contrib/py-bindings/gfmodule.c
@@ -245,13 +245,33 @@ unapp(Expr *self) {
   return obj;
 }
 
+static PyObject*
+infer_expr(Expr *self, PyObject* args) {
+  PGF* pgf;
+  if (!PyArg_ParseTuple(args, "O", &pgf))
+    return NULL;
+  if (!checkType(pgf, &PGFType)) {
+    PyErr_Format(PyExc_ValueError, "Must be a pgf module.");
+    return NULL;
+  }
+  gfType* gftp = (gfType*)gfTypeType.tp_new(&gfTypeType,NULL,NULL);
+  gf_inferexpr(pgf, self, gftp);
+  return gftp;
+}
+
+
+
+/* todo: Is Tree == Expr ?
+
 static PyMethodDef tree_methods[] = {
-  {"unapply", (PyCFunction)unapp, METH_NOARGS,"Unapply a tree."},
-  {NULL, NULL, 0, NULL}  /* Sentinel */
+  {"unapply", (PyCFunction)unapp, METH_NOARGS, "Unapply a tree."},
+  {NULL, NULL, 0, NULL}  // * Sentinel * //
 };
+*/
 
 static PyMethodDef expr_methods[] = {
-  {"unapply", (PyCFunction)unapp, METH_NOARGS,"Unapply an expression."},
+  {"unapply", (PyCFunction)unapp, METH_NOARGS, "Unapply an expression."},
+  {"infer", (PyCFunction)infer_expr, METH_VARARGS, "Infer the type of an expression."},
   {NULL, NULL, 0, NULL}  /* Sentinel */
 };
 
@@ -297,7 +317,7 @@ initgf(void)
 	READYTYPE(gfTypeType, gfType_repr, gfType_dealloc)
         ExprType.tp_methods = expr_methods;
 	READYTYPE(ExprType, expr_repr, expr_dealloc)
-	TreeType.tp_methods = tree_methods;
+	TreeType.tp_methods = expr_methods; // Tree == Expr ?
 	READYTYPE(TreeType, tree_repr, Tree_dealloc)	
 
   m = Py_InitModule3("gf", gf_methods,
diff --git a/contrib/py-bindings/test.py b/contrib/py-bindings/test.py
index 253360a4f..04adb2c29 100644
--- a/contrib/py-bindings/test.py
+++ b/contrib/py-bindings/test.py
@@ -142,5 +142,17 @@ class TestUnapplyExpr(unittest.TestCase):
 			uparsed = self.deep_unapp(parsed[0])
 			self.assertEqual(abs,uparsed)
 
+	def test_infer(self):
+		lg = 'eng'
+		lang = self.langs[lg]
+		cnc = self.samples[0][1]
+		parsed = self.pgf.parse(cnc[lg],lang)
+		exp = parsed[0]
+		for t in 'Question Object Int'.split():
+			self.assertEqual(`exp.infer(self.pgf)`, t)
+			uexp = exp.unapply()
+			if type(uexp) != type(2) and type(uexp) != type('2'):
+				exp = uexp[1]
+
 if __name__ == '__main__':
 	unittest.main()