Version 0.0.3

This implements a simple lexer and simple parser.

Tokens:

• PLUS = +
• MINUS = -
• ASTERISK = *
• F_SLASH = /
• OPEN_PAREN (not parseable yet) = (
• CLOSE_PAREN (not parseable yet) = )
• NUMBER = /d+
• EEOF = \0
• UNKNOWN = (anything else)

Syntax:

expr     : term ((PLUS|MINUS) term)*

term     : factor ((ASTERISK|F_SLASH) factor)*

factor   : NUMBER