public void Define(
AST.StructOrUnion structOrUnion,
ImmutableList<Tuple<Option<String>, ExprType>> members) {
var _members = members.ConvertAll(_ => Tuple.Create(_.Item1.Value, _.Item2));
if (structOrUnion == AST.StructOrUnion.STRUCT) {
DefineStruct(_members);
} else {
DefineUnion(_members);
}
}