Re: [Ocaml-lib-devel] ExtString module updated

[Brian H. <bri...@ql...>]

On Thu, 22 May 2003, Michal Moskal wrote:

> > Sanity check this code, if you will:
> > 
> >             if i >= (m - 1) then next
>                       ^^^^^^^
> 
> I'm not quite sure how good is ocamlc wrt moving constants out of loop,
> but probably moving this substraction out of the loop would be The Right
> Thing.

For a simple decrement I wouldn't worry too much about strength reduction.  
At worst it's a single clock cycle cost- i.e. too low to notice generally.

> > And it gets rid of all the references- 
> > which probably means a speed up (haven't tested it yet though).  
> 
> Maybe refs are optimized away by the compiler? But I don't know.

I don't know either.

> 
> > Although 
> > one thing we might want to consider: actually exporting the kmp_init 
> > function and kmp function seperately.  This way if I wanted to find the 
> > same substring in a lot of different strings, I don't have to constantly 
> > recreate the next table.  Maybe something like:
> [snip]
> 
> I think better as submodule:

Yes.  Can we do modules in modules?  I.e.: String.KMP.compile and 
String.KMP.match, like:

    let pat = String.KMP.compile p in
    String.find_all (fun s -> try let _ = String.KMP.match pat s in true
                              with Not_found -> false) strlist

Brian