exceptions in CamlLight 0.7 and OCaml

exceptions in CamlLight 0.7 and OCaml

[Kwangkeun Yi]

Hi there,

I have a quick question. Does OCaml have the same implementation for
exceptions as in CamlLight 0.7?

We want to test our source-level transformation of Standard ML programs
in both SML/NJ and OCaml. But because what we want to measure is only
about exceptions, if CamlLight implementation of exceptions is the
same as in OCaml we can use the Moscow ML without having to translate
our SML benchmarks into Caml.

-Kwang

-- 
Kwangkeun Yi		http://cs.kaist.ac.kr/~kwang

Re: exceptions in CamlLight 0.7 and OCaml

[Xavier Leroy]

> I have a quick question. Does OCaml have the same implementation for
> exceptions as in CamlLight 0.7?

The implementation model for exceptions is similar.  However, the
virtual machines of Caml Light and OCaml have significant differences;
not to mention the OCaml native-code compiler.

> We want to test our source-level transformation of Standard ML programs
> in both SML/NJ and OCaml. But because what we want to measure is only
> about exceptions, if CamlLight implementation of exceptions is the
> same as in OCaml we can use the Moscow ML without having to translate
> our SML benchmarks into Caml.

You can always run your tests under Moscow ML, but don't extrapolate
the results to Caml Light and especially not to OCaml; that would not
be scientific.

- Xavier Leroy

Re: exceptions in CamlLight 0.7 and OCaml

[Ken Friis Larsen]

Hi,

 Kwangkeun>  I have a quick question. Does OCaml have the same
 Kwangkeun>  implementation for exceptions as in CamlLight 0.7?
 
This I cannot answer with authority (but according to my memory, the
answer is yes)

 Kwangkeun>  if CamlLight implementation of exceptions is the same as
 Kwangkeun>  in OCaml we can use the Moscow ML without having to
 Kwangkeun>  translate our SML benchmarks into Caml.

I don't think that this will measure what you think it will measure.
Remember that exception differs slightly in SML and Caml: In SML
exceptions are generative.  In Moscow ML 2.00[1] _all_ SML exceptions
are roughly encoded as Caml exceptions of the form:

        exception SMLexc of string ref * 'a

(In the modified CamlLight runtime system of cause.  The code above is
not valid Caml.)

Where the string ref corresponds to the name of the exception.

Hope this helps.


Cheers,

--Ken


[1] Earlier implementations of Moscow ML used a much complicated
encoding where some exceptions had one encoding and others another.