cl-lex
cl-lex is a set of Common Lisp macros for generating lexical analyzers automatically. Registers (including named registers) can be accessed by number or name in token generation code. The cl-ppcre regex library is used for implementing regular expressions. Lexers generated using cl-lex can be used with cl-yacc.

ASDF-install package (obsolete) http://cl-lex.googlecode.com/files/cl-lex_1.1.3.tar.gz