conjunction queries

python/sandbox/das_gate/dasgate.py

@@ -38,8 +38,11 @@ def _atom2dict(self, atom):
 
     def _atom2query(self, atom):
         if isinstance(atom, ExpressionAtom):
+            targets = atom.get_children()
+            if isinstance(targets[0], SymbolAtom) and targets[0].get_name() == ',':
+                return And([self._atom2query(ch) for ch in targets[1:]])
             return Link("Expression", ordered=True,
-                targets=[self._atom2query(ch) for ch in atom.get_children()])
+                targets=[self._atom2query(ch) for ch in targets])
         else:
             if isinstance(atom, VariableAtom):
                 return Variable(repr(atom))

python/sandbox/das_gate/test_das.metta

@@ -3,8 +3,19 @@
 !(bind! &das (new-das))
 
 !(add-atom &das (Test (Test 2)))
+!(add-atom &das (Best (Test 2)))
 !(add-atom &das Test)
 
+; The simplest match with grounding the variable in the node
 !(match &das ($v1 (Test 2)) (This $v1 works))
+; The simplest match with grounding the variable in the link
 !(match &das (Test $v2) (This $v2 works))
+
+!(add-atom &das (Rest (Test 3)))
+!(add-atom &das (Test (Test 3)))
+
+; Compositional (And) query test
+!(match &das (, (Best $x) ($v $x)) ($v $x))
+; !(match &das (, ($v1 $x) (Test $x)) ($v1 Test $x))
+
 ; !(match &das ($v1 ($v2 2)) (This $v1 works))