About the macro expander

[Xue Fuqiao]

In the trunk version of (info "(cl) Type Predicates"):

 -- Macro: cl-deftype name arglist forms...
     The type specifier `(NAME ARGS...)' is expanded by calling the
     expander with those arguments; the type symbol `NAME' is expanded
     by calling the expander with no arguments.  The ARGLIST is
     processed the same as for `cl-defmacro' except that optional
     arguments without explicit defaults use `*' instead of `nil' as the
     "default" default.

It says "calling the expander with no arguments", but I don't know what
is the argument of expander (what the argument of expander should be).
I have searched the Emacs FAQ, Emacs Lisp manual, cl-lib manual and the
web, but I don't find anything useful.  Can anybody help (is there an
argument list of the expander)?  Thanks a lot.

-- 
Best regards, Xue Fuqiao.
http://www.emacswiki.org/emacs/XueFuqiao