Initial Lexer implementation, along with tests and driver module
Simplify lexer constructor
Fix lexing reserved words
Fix tracking of Beginning Of Line. Pack lexer in one class
Build lexer in a single step
Guard against FP irrepresentable by machine
Restrict lexing to ASCII-only files.
Change LlamaLexer interface to conform to yacc expectations.
Simplify lexer debugging.
Expose tokens in lexer module. Code cleanup.
LlamaLexer can now clone itself.