Implement proper constant support 7/n

src/operators/operator.py

@@ -275,6 +275,7 @@ class Operator(metaclass=NiftyMeta):
         from .simplify_for_const import ConstantEnergyOperator, ConstantOperator
         from ..multi_field import MultiField
         from ..domain_tuple import DomainTuple
+        from ..sugar import makeDomain
         if c_inp is None or (isinstance(c_inp, MultiField) and len(c_inp.keys()) == 0):
             return None, self
         dom = c_inp.domain
@@ -298,7 +299,17 @@ class Operator(metaclass=NiftyMeta):
             return None, op
         if not isinstance(dom, MultiDomain):
             raise RuntimeError
-        return self._simplify_for_constant_input_nontrivial(c_inp)
+        c_out, op = self._simplify_for_constant_input_nontrivial(c_inp)
+        vardom = makeDomain({kk: vv for kk, vv in self.domain.items()
+                             if kk not in c_inp.keys()})
+        assert op.domain is vardom
+        assert op.target is self.target
+        assert isinstance(op, Operator)
+        if c_out is not None:
+            assert isinstance(c_out, MultiField)
+            assert len(set(c_out.keys()) & self.domain.keys()) == 0
+            assert set(c_out.keys()) <= set(c_inp.keys())
+        return c_out, op
 
     def _simplify_for_constant_input_nontrivial(self, c_inp):
         from .simplify_for_const import InsertionOperator