Re: What is a lightweight language

[Matthias Felleisen <address@hidden>]

  > From: "Christopher Barber" <cbarber@curl.com>
  > Cc: <ds26@gte.com>, <ll1-discuss@ai.mit.edu>
  > Date: Tue, 11 Dec 2001 13:51:34 -0500
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  > 
  > >the question is whether there is a performance cost for programs in
  > > L minus feature F. This is called F's opportunity cost. (Okay, I do have
  > > some funny business degree.) Closures have a cost, continuations do, set!
  > > has a huge cost, etc. 
  > 
  > Interesting!  But how exactly do you quantify these costs?
  > 
  > - Christopher
  > 

Kent Dybvig (INDIANA) has done a very careful implementation of
continuations and deep recursion in a non-continuation compiler. 
He knows which bytes on the stack are necessary because he does 
callcc and not just deep recursion gracefully. So in his compiler
we know pretty much how much more you allocate and how much this 
costs on regular programs. "Know" means careful estimate. I vaguely 
recall a number of less than 5%, which is pretty small and some 
argue not measurable (just like with the GDP). 

Others have done similar analyses for other features. No systematic study
of the entire language spectrum as far as I know.

-- Matthias