Personally, I think the only sensible way to handle this problem is to require the user to specify an ordering function. We can of course provide a default, which will be error-prone but tend to work most of the time.
The function called "my-generic-less-than" which is in the source tree now could be a starting point for a generic ordering. On Tue, 2007-07-24 at 09:48 -0400, Ian Eslick wrote: > Robert and I have had some extended discussions on ordering in > indices. I think that all we really need to agree on is _some_ > canonical ordering. If we have mixed types in an index, how should > they be ordered relative to each other? In BDB we have a C function > which implements the ordering based on the type tag and then based on > the type within it. Are you relying on a pure binary sort in > postmodern? > > Robert or I will get to submitting that patch shortly. I have > recently sent in a patch to lisp-compare<= so we'll see if we had to > make parallel changes. > > > Thanks, > Ian > > On Jul 24, 2007, at 3:50 AM, Henrik Hjelte wrote: > > > I sent this message yesterday but I guess it got stuck in the mailing > > list filter. Perhaps the attachment was too big. Since my > > common-lisp.net user hhjelte does not have write access to elephant I > > have placed the patches from here instead: > > darcs get http://common-lisp.net/project/grand-prix/darcs/elephant > > > > ---------- Forwarded message ---------- > > From: Henrik Hjelte <[EMAIL PROTECTED]> > > Date: Jul 23, 2007 11:28 PM > > Subject: some patches > > To: elephant-devel@common-lisp.net > > > > > > Here are some darcs patches that might be of interest. I had some > > problems with map-index on db-postmodern that made me almost rip my > > hair of, but finally I made it to work again. The problem is that > > map-index for a string value rely on the ordering in the btree > > (continue-p makes use of less than for strings). The postmodern > > backend relies on how the database backend orders things, which is not > > always the same thing. Is it a necessary feature that b-trees of > > string and objects are required to be ordered by lisp-compare<=? > > > > In the process of solving the bug I have upgraded the test framework > > to use FiveAM instead of RT, It has in my opinion a very nice syntax > > and some useful features to track dependencies between tests. I hope > > you agree that it improves on things. > > > > /Henrik Hjelte > > _______________________________________________ > > elephant-devel site list > > elephant-devel@common-lisp.net > > http://common-lisp.net/mailman/listinfo/elephant-devel > > _______________________________________________ > elephant-devel site list > elephant-devel@common-lisp.net > http://common-lisp.net/mailman/listinfo/elephant-devel
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