On Fri, 24 Dec 2010, Eli Barzilay wrote: > The only thing that looks close to a reason is your desire to be able > to customize the equality that it uses -- yet this doesn't require > forcing a macro implementation. For example, the text could replace > > in the sense of `eqv?' > > with > > in the sense of the current lexical binding for `eqv?' > > and you get your kind of customization hook without a requirement on > the implementation. > > As for the hook itself, there is first the question of why a hook is > needed, and then there's how it should be implemented. The solution > of mutating `eqv?' is pretty horrible IMO -- and it's worse when you > actually want to do this by a `define'. If anything, you should go > with advocating a plain `set!' which would clarify that you really > want some more "hook-ish" name like `current-equality', and better to > use some feature that avoids race conditions for threaded > implementations (eg, racket parameters).
Yes. Peter, the better way to do the kind of thing you are looking for is PARAMETERIZE. I wouldn't advocate it for CASE, though. Andre _______________________________________________ r6rs-discuss mailing list r6rs-discuss@lists.r6rs.org http://lists.r6rs.org/cgi-bin/mailman/listinfo/r6rs-discuss
