Re: Translators, yet once more (Re: PHP fork project- Guile vs Python vs ?)

[Michael Vanier <mvanier at bbb dot caltech dot edu>]

> From: "Khimenko Victor" <guile@khim.sch57.msk.ru>
> 
> 10-Jul-00 15:31 you wrote:
> > On Mon, 10 Jul 2000, Ken Anderson wrote:
> 
> >> I like the translate into Scheme approach, but won't the guile debugger produce a scheme backtrace rather than a python one?
> 
> > Tracebacks aren't part of the language definition. (Exceptions are though,
> > but I'm planning to simulate those with continuations, and not rely on whatever mechanism guile develops for exceptions)
> 
> Don't to it ! Continuations are REAL slow in guile and Python relies on
> exceptions quite heavily.
> 
> 

My understanding of this is that guile implements continuations by
stack-copying (the C stack IIRC), which is what slows it down.  My question
is: is this really necessary?  Python has a "stackless" fork (i.e. one that
doesn't use the C stack at all) which allows for efficient continuations,
and the claim is that this doesn't slow down the language appreciably.
Would a "stackless" guile permit more efficient continuations?  What kind
of tradeoffs are involved?

Mike