Portable way to get a function's arg list (ala Control-Shift-A)?

[barmar@Think.COM (Barry Margolin)]

    Date: Mon, 23 Mar 1992 17:03 EST
    From: Healy@space50.nrl.navy.mil (Liam M. Healy)

	Date: Mon, 23 Mar 1992 16:40 EST
	From: hall@aplcen.apl.jhu.edu (Marty Hall)

	Is there a portable way to get the parameter list to a function?
	Ie I want a way to be able to tell the user that function Foo
	has two required args named xxx and yyy and one &optional arg
	named zzz with a default value of aaa, just as Symbolics does
	with control-shift-A (and elsewhere).  I tried to see how Symbolics did
	it, but I couldn't find anything portable, especially as I'm not
	allowed to assume anything about the structure of the object "function"
	or "symbol-function" returns (right?). IS there a way?

	I assume the answer is "no", but I wanted to confirm this with the
	wizards.
						- Marty
	(setf (need-p 'disclaimer) NIL)

    arglist, e.g.: (arglist 'foo) returns information on function foo.
    As near as I can tell this is Symbolics, not CL.  But I'm no
    wizard.

There is no fully portable function that does this.  But I'll bet
several other CL implementations have an ARGLIST function.  Lucid does.

                                                barmar