On Fri, Oct 28, 2011 at 2:28 PM, Joe Marshall <jmarsh...@alum.mit.edu> wrote: > On Fri, Oct 28, 2011 at 11:08 AM, Carl Eastlund <c...@ccs.neu.edu> wrote: >> >> You seem to be assuming that we have to pick one binary->nary for all >> binary operators. > > That is the nature of `generalization'. If I have to discriminate, it isn't > general.
Only if our job is to generalize binary operators as a class to n-ary operators. This thread is about generalizing <= (and a few related operators) to n-ary operators. We can do the latter without doing the former. >> I would choose this one for relations and the other >> one for associative operators with identities. > > And you thus answer the original poster's question. > `` is there a rationale beyond historical precedent > for + and * to allow any number of arguments but, =, <=, <, >, >= to > require at least two arguments?'' > > Yes. The two generalizations are different. How is that a rationale? I don't see why this kind of difference is in any way an argument against generalization. It may be a reason that the designers thought of one kind of generalization but not the other, but that's in the category of historical precedent. > I made a clumsy argument to this effect by showing that the natural > generalization > for add and multiply do not extend to relational operators. --Carl _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
