new version of python interface

packages/python/yapex.py

@@ -0,0 +1,79 @@
+import yap
+
+# this class is not being used
+# we rely on namedtuples instead.
+class T(tuple):
+
+    """Represents a non-interned Prolog atom"""
+    def __new__(self, s, tple):
+        self.tuple.__new__(self, tple)
+        self.name = s
+
+    def __repr__(self):
+        return "yapex.T(" + self.name + " , " + tuple.__repr__(self) + ")"
+
+    def __str__(self):
+        return str(self.name) + str(self.tuple)
+
+
+def query_prolog(engine, s):
+    q = engine.query(s)
+    ask = True
+    while q.next():
+        vs = q.namedVarsCopy()
+        if vs:
+            i = 0
+            for eq in vs:
+                name = eq[0]
+                bind = eq[1]
+                if bind.isVar():
+                    var = yap.YAPAtom('$VAR')
+                    f = yap.YAPFunctor(var, 1)
+                    bind.unify(yap.YAPApplTerm(f, (name)))
+                else:
+                    i = bind.numberVars(i, True)
+                    print(name.text() + " = " + bind.text())
+        print("yes")
+        if q.deterministic():
+            q.close()
+            return
+        if ask:
+            s = input("more(;/y),  all(!/a), no ?").lstrip()
+            if s.startswith(';') or s.startswith('y'):
+                continue
+            elif s.startswith('#'):
+                exec(s.lstrip('#'))
+            elif s.startswith('a'):
+                ask = False
+            else:
+                break
+    print("No (more) answers")
+    q.close()
+    return
+
+
+def live():
+    engine = yap.YAPEngine()
+    loop = True
+    while loop:
+        try:
+            s = input("?- ")
+            if not s:
+                loop = False
+            query_prolog(engine, s)
+        except SyntaxError as err:
+            print("Syntax Error error: {0}".format(err))
+        except EOFError:
+            return
+        except RuntimeError as err:
+            print("YAP Execution Error: {0}".format(err))
+        except ValueError:
+            print("Could not convert data to an integer.")
+        except:
+            print("Unexpected error:", sys.exc_info()[0])
+            raise
+
+#
+# initialize engine
+# engine = yap.YAPEngine();
+# engine = yap.YAPEngine(yap.YAPParams());