Subject: Re: macros vs HOFs (was: O'Caml) From: Erik Naggum <erik@naggum.no> Date: 13 Sep 2002 23:41:16 +0000 Newsgroups: comp.lang.lisp Message-ID: <3240949276974621@naggum.no> * Gareth McCaughan | It's sort of true that if you're doing static types then you need to | consider types to be disjoint, in that you need to know *the* type of every | expression in the program, but that's perfectly compatible with having | subtype relations too. Integer can be a subtype of Rational even if | everything gets typed either as Integer or as Ratio. One of the major problems I have with strong typing is precisely that it flies in the face of another pretentious theory, object-orientation, which supposedly should have a type hierarchy and run-time dispatch on the type of the actual object. The two theories seem to be seriously at odds. What we have in Common Lisp is thoroughly object-oriented approach. This should be good, but somehow the strongly-typed nutjobs go "eep, eep" (thanks, Tim) and seem to ignore that their theories are all bunk if they cannot handle a type hierarchy. Even before I started programming in Common Lisp, I found the desire to know /the/ (single) type of every expression to be suspect and the theories wanting when they made that premise. As if you could not reason about types unless you had only one type! As if you could not operate with union types created on the fly! All bunk, I say. | Of course, (truncate (/ x y)) feels inefficient. But it doesn't take a | specially smart compiler to make that feeling an illusion. Not so. Please remember the secondary return value. -- Erik Naggum, Oslo, Norway Act from reason, and failure makes you rethink and study harder. Act from faith, and failure makes you blame someone and push harder.