public DataType VisitList(PyList l)
{
var listType = new ListType();
if (l.elts.Count == 0)
{
return(listType); // list of unknown.
}
foreach (var exp in l.elts)
{
listType.add(exp.Accept(this));
if (exp is Str sExp)
{
listType.addValue(sExp.s);
}
}
return(listType);
}
