Saving before modifying TypeEnv
Basic.java works
Doing well so far. From now, focus on fixing the cases that causes problem. Start from the small program.
Commit Before Separation.
no exeception for BuildVisitor.java. Have to verify each scope
Almost separate BuildVisitor and TypeCheckVisitor.
Not easy. revise this and messagesend, also simplify te and scope
Finally No Nullpointer exception. Apply test one by one now.
Keep on
struggling with structures
Should I restart?