On Wed, 22 Dec 2010, John Cowan wrote: > However, this is a problem not of hygiene but of reusing implementation, > I think. Consider this: > > (define cdr #f) > (length '(a b c)) > > I haven't found any Schemes except Scheme 9 on which this fails, but > there is nothing in any Scheme standard to make it work.
R5RS chapter 6 intro: A program may use a top-level definition to bind any variable. It may subsequently alter any such binding by an assignment (see 4.1.6). These operations DO NOT MODIFY the behavior of Scheme's built-in procedures. Andre _______________________________________________ r6rs-discuss mailing list r6rs-discuss@lists.r6rs.org http://lists.r6rs.org/cgi-bin/mailman/listinfo/r6rs-discuss