Re: Strong Typing, Dynamic Languages, What to do?

[Michael Vanier <mvanier@cs.caltech.edu>]

> X-Authentication-Warning: fast.cs.utah.edu: majordom set sender to owner-plt-scheme@flux.cs.utah.edu using -f
> From: Matthias Felleisen <matthias@ccs.neu.edu>
> Reply-To: matthias@ccs.neu.edu
> Date: Fri, 22 Mar 2002 16:35:34 -0500 (EST)
> 
> Jerzy, 
> 
> with all due respect, I think Noel was on to the right answer.
> 
> And why does SML's performance suck, if static types are really all that
> great for performance? Once you have polymorphism you don't need dynamic 
> types to mess up your performance. 

And yet ocaml's performance is really good.  I thought at least part of the
reason for this was that ocaml uses the stack in much the same way that C
does (which pretty much rules out continuations) while SML is more
scheme-like in its stack management (and has continuations).

OTOH Common Lisp systems, which are dynamically typed by default, can
compile to very fast code as well.  Certainly the presence of run-time
checks can slow your program down a lot, but there's nothing in scheme or
lisp which prevents the implementor from removing these checks if possible.
Some schemes (bigloo, dunno about chez) have type declarations, for
instance, and all CL systems have them.

Mike