Recall our WhileParser.scala

• each function returned unit (void) type

Now: each function

• extracts information from tokens
• obtains information from recursive calls
• returns a new tree.scala node

Result: ParserTrees.scala (email me any errors you notice)

• test program: isquares.while

To try it out:

scalac Lexer.scala Trees.scala ParserTrees.scala
scala -cp . ParserTest isquares.while