Project 2: Parser for the PASC language.  The project has these files:

	driver2.c: driving program to check command line options and invoke
		   yypase().

	parser.y: grammar definitions and semantic actions to build a syntax
		  tree.

	tree.c:  routines to build and test the syntax tree; some functions
		 are updated and new functions are added for convenience.

	tree.h:  tree node definitions.

	lexer.l: lex file from project 1; It generates tokens and maintains
		  a string buffer containing all lexemes.
        table.c : implementation of a hash table and string buffer used to
                  store lexemes (identifiers and string constants).

To run the parser, type 'make' or 'make -f parse.mk' followed by:

		parser [-da [-dt [outfile]]] < file.pasc
		
The flag '-da' turns on tracing and '-dt' outputs the syntax tree to 'outfile'.
If no file is specified, stdout is assumed.  The parser reports any errors
found along with the line and column numbers.