I am trying to use cl-lexer and when I tried writing my own example, I was getting some errors. I installed using quicklisp, first directly and then I cloned the git repo. Either way, the following shows what happens when I try to run the example.lisp file. Is there some dependency I'm missing? Thanks.

$ sbcl
This is SBCL 1.0.55.0.debian, an implementation of ANSI Common Lisp.
More information about SBCL is available at http://www.sbcl.org/.

SBCL is free software, provided as is, with absolutely no warranty.
It is mostly in the public domain; some portions are provided under
BSD-style licenses. See the CREDITS and COPYING files in the
distribution for more information.

• (load "quicklisp/local-projects/cl-lexer/example")

; file: /home/mgcheung/quicklisp/local-projects/cl-lexer/example.lisp
; in: DEFLEXER TEST-LEXER
; (LEXER:DEFLEXER TEST-LEXER::TEST-LEXER
; ("[0-9]+([.][0-9]+([Ee][0-9]+)?)"
; (RETURN (VALUES 'TEST-LEXER::FLT (LEXER:NUM LEXER:%0))))
; ("[0-9]+" (RETURN (VALUES 'LEXER:INT (LEXER:INT LEXER:%0))))
; ("[:alpha:][:alnum:]*"
; (RETURN (VALUES 'TEST-LEXER::NAME LEXER:%0)))
; ("[:space:]+"))
; --> PROGN
; ==>
; (LEXER::MACROEXPAND-REGEX-EXPR
; '(REGEX::ALT (REGEX::SEQ (REGEX::REG 0 (REGEX::SEQ # #)) (REGEX::SUCCEED 0))
; (REGEX::SEQ (REGEX::REG 0 (+ #)) (REGEX::SUCCEED 1))
; (REGEX::SEQ (REGEX::REG 0 (REGEX::SEQ # #)) (REGEX::SUCCEED 2))
; (REGEX::SEQ (REGEX::REG 0 (+ #)) (REGEX::SUCCEED 3))))
;
; caught STYLE-WARNING:
; undefined function: LEXER::MACROEXPAND-REGEX-EXPR
;
; compilation unit finished
; Undefined function:
; LEXER::MACROEXPAND-REGEX-EXPR
; caught 1 STYLE-WARNING condition

debugger invoked on a UNDEFINED-FUNCTION in thread

<THREAD "initial thread" RUNNING {1002998D53}>:

The function LEXER::MACROEXPAND-REGEX-EXPR is undefined.

Type HELP for debugger help, or (SB-EXT:QUIT) to exit from SBCL.

restarts (invokable by number or by possibly-abbreviated name):
0: [RETRY ] Retry EVAL of current toplevel form.
1: [CONTINUE] Ignore error and continue loading file "/home/mgcheung/quicklisp/local-projects/cl-lexer/example.lisp".
2: [ABORT ] Abort loading file "/home/mgcheung/quicklisp/local-projects/cl-lexer/example.lisp".
3: Exit debugger, returning to top level.

("undefined function")
0]

Please consider adding :description, :author and :license information to your ASDF system(s). This will greatly help Quicklisp users and make it easier for them to report bugs.

More information:

http://blog.quicklisp.org/2015/05/looking-for-more-metadata.html
https://www.quicklisp.org

According to ASDF best practices you should rename this project package to be consistent with the naming scheme. As of right now this project shows up as cl-lexer on quickdocs. i.e. the defsystem and exported package should be named cl-lexer to be in line with the project name, or rename the repo to be lexer. As this is causing clashing issues with other packages.