[Ecls-list] Status of CVS

Juan Jose Garcia-Ripoll jjgarcia at users.sourceforge.net
Mon May 12 14:12:21 UTC 2008


On Mon, May 12, 2008 at 4:06 PM, Gabriel Dos Reis
<gdr at integrable-solutions.net> wrote:
> On Mon, May 12, 2008 at 3:53 AM, Juan Jose Garcia-Ripoll
>  <jjgarcia at users.sourceforge.net>
> >  So why is this so? The reason is that SBCL (and probably CMUCL)
>  >  automatically inserts type checks at the beginning of this function.
>  >  These checks will ensure that the arguments of the function have the
>  >  right types or, otherwise, enter the debugger.
>
>  I've found that behaviour highly helpful when porting Axiom to SBCL -- in
>  contrast, ECL's compiler would silently die with `mysterious' files
>  left all over  the places. It is an invaluable debugging tool, especially when
>  porting legacy codes  to newer systems.

Perhaps, but that also shows the code is broken. So it can be
understood as a debugging tool, but given that it is not specified in
the standard as a portable behavior, I find it really annoying that
programmers rely on that instead of using their own check-type forms.

>  >  So, from now on, ECL will follow this nonstandard behavior and also
>  >  generate safety checks if SAFETY >= 1.
>
>  Excellent!  If the check were cheap, I would even suggest to add them
>  at safety 0.

Type checks can be expensive. Why do you want to enforce them on
people at all levels?

Juanjo

-- 
Facultad de Fisicas, Universidad Complutense,
Ciudad Universitaria s/n Madrid 28040 (Spain)
http://juanjose.garciaripoll.googlepages.com




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