def visit_DictLookup(self, node):
node = self.generic_visit(node)
# Only simple map lookups are allowed.
assert isinstance(node.value, L.Name)
assert L.is_tuple_of_names(node.key)
assert node.default is None
map = node.value.id
keyvars = L.detuplify(node.key)
var = self.repls.get(node, None)
if var is None:
mask = L.mapmask_from_len(len(keyvars))
rel = N.SA_name(map, mask)
# Create a fresh variable.
self.repls[node] = var = next(self.fresh_names)
# Construct a clause to bind it.
vars = list(keyvars) + [var]
new_clause = L.SetFromMapMember(vars, rel, map, mask)
self.new_clauses.append(new_clause)
# Construct a corresponding SetFromMap invariant.
sfm = SetFromMapInvariant(rel, map, mask)
self.sfm_invs.add(sfm)
return L.Name(var)
def visit_SetFromMap(self, node):
self.generic_visit(node)
if not isinstance(node.map, L.Name):
return
map = node.map.id
rel = N.SA_name(map, node.mask)
setfrommap = SetFromMapInvariant(rel, map, node.mask)
self.setfrommaps.add(setfrommap)