Updates to Lexer for Handling Comments

• Lexer eating comments: I have just put a new version of Yylex.java on the web page. The .zip and .sit files have also been updated to include this new version. This version is intended to correct problems with the lexer eating /*...*/ style comments.

  Please note:

  • We truly apologize for causing people problems. Here's a deal: We won't test your programs on files with comments, so while we will provide a lexer that swallows them, if you get a headache, please do the needful and remove comments from your test programs.
  • I have heard a couple people have problems with // style comments. I am still waiting to see these people's programs and determine the problem. Updates will be posted here in a timely manner.

  --Dan Grossman, CS211 TA

• Grammar issue:

  Thanks to one of my sections, we discovered a difference between the JavaDUCK grammar and the real Java grammar.

  In Java, an abstract method has a semicolon after right parenthesis that ends the parameter list. And it has no body (i.e. a balanced curly block). In JavaDUCK, all methods, including abstract ones, have bodies and never semicolons.

  THE GRAMMAR WE GAVE YOU IS THE FINAL WORD! Do what the handout says -- assume ALL METHODS HAVE BODIES AND NONE HAVE SEMICOLONS. We will test your program according to this assumption.

  This decision has the advantage that there is technically NO CHANGE to the assignment. It has the disadvantage that we _thought_ JavaDUCK files were also legal Java files, but we were not quite right. My sincerest apologies.

  -- Dan, CS211 TA