Re: [Ocaml-lib-devel] a bug in BitSet?

[Bardur A. <oca...@sc...>]

On Fri, Dec 24, 2004 at 10:05:10PM +1100, skaller wrote:

> On Fri, 2004-12-24 at 11:31, Janne Hellsten wrote:
> 
> > Since I guess people are not willing to stop using unsafe_get/put (at 
> > least not completely), we should think of some other way to achieve 
> > bounds checking so that it doesn't hurt performance.
> 
> Why doesn't just the usual get/put and compilation with -unsafe 
> for a production build work? I mean that's the idea of -unsafe 
> isn't it?

Well, it probably works, but it requires even more
confidence that the code is correct, because suddenly
*every* array/string access becomes unsafe.

I don't think I have that much confidence in the extlib
code right now...

[--snip--]
> >The debug build would always have 
> >assertions on and thus be slower.  However, it would only be used for 
> >testing purposes.

I think this could be implemented by using pa_macro and
adding something like (syntax might be slightly wrong, I
usually use revised syntax)

     IFDEF DEBUG
        module String = struct
             include String	
             val unsafe_get = get
             val unsafe_set = set
        end

        module Array = struct
             include Array
             val unsafe_get = ...
             ...
        end	     
     ENDIF

at the beginning of modules using unsafe_get/set... (You
can also use the pa_macro INCLUDE directive, add the above
to a file and include that in the appropriate places).

This should allow you to enable/disable bounds checking at
compilation time.

-- 
Bardur Arantsson
<ba...@im...>
<ba...@sc...>

The best part? I became an ordained minister while not wearing
pants.