Here are two alternative formulations of keywords, both based on the
idea that keywords are pure syntax, with no representation at run time.

1) Keyword-value arguments are sorted into order corresponding to
the alphabetical order of the keywords.  Thus  (foo 'bar foo: 32 bar: 54)
comes out at run time as (foo 'bar 54 32).  Similar treatment is
given to keywords in lambda lists.  (Note: forcer came up with this
one independently.)

2) Keywords are syntactic sugar for a single argument in the form of an
a-list.  This maps (foo 'bar foo: 32 bar: 54) to
(foo 'bar '((foo: . 32) (bar: . 54))).  Keywords in lambda lists are
initialized by unpacking the a-list when the procedure is invoked.

--
John Cowan                                <xxxxxx@ccil.org>
Yakka foob mog.  Grug pubbawup zink wattoom gazork.  Chumble spuzz.
    -- Calvin, giving Newton's First Law "in his own words"