Expand Up @@ -3468,7 +3468,7 @@ def visit_op_expr(self, e: OpExpr) -> Type: # It's actually a type expression X | Y. return self.accept(e.analyzed) if e.op == "and" or e.op == "or": return self.check_boolean_op(e, e) return self.check_boolean_op(e) if e.op == "*" and isinstance(e.left, ListExpr): # Expressions of form [...] * e get special type inference. return self.check_list_multiply(e) Expand Down Expand Up @@ -4255,20 +4255,18 @@ def check_op( context=context, )
def check_boolean_op(self, e: OpExpr, context: Context) -> Type: def check_boolean_op(self, e: OpExpr) -> Type: """Type check a boolean operation ('and' or 'or')."""
# A boolean operation can evaluate to either of the operands.
# We use the current type context to guide the type inference of of # We use the current type context to guide the type inference of # the left operand. We also use the left operand type to guide the type # inference of the right operand so that expressions such as # '[1] or []' are inferred correctly. ctx = self.type_context[-1] left_type = self.accept(e.left, ctx) expanded_left_type = try_expanding_sum_type_to_union( self.accept(e.left, ctx), "builtins.bool" ) expanded_left_type = try_expanding_sum_type_to_union(left_type, "builtins.bool")
assert e.op in ("and", "or") # Checked by visit_op_expr
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