HashSet is fine, and the best we've currently got, but let the caller
of StopFilter choose that. Other, better, Set implementations may be
widely available one day.
Otis
--- Erik Hatcher <[EMAIL PROTECTED]> wrote:
> This, too, is my preferred approach.... it just seemed such a strong
> argument for HashSet everywhere. I particularly agree with the lack
>
> of need to enforce HashSet.
>
> Erik
>
> On Mar 11, 2004, at 8:29 AM, Otis Gospodnetic wrote:
>
> > I agree, partially, with Doug about not copying thing and that use
> of
> > instanceof.
> >
> > The part where I don't agree is where I agree with what Scott Ganyo
> > said, and with Erik's initial approach: use interfaces. I don't
> see a
> > need to epxose that HashSet. Just use Set.
> >
> > Well, maybe not even an internal HashSet enforcement needs to be
> made.
> > Why not leave it up to the caller to pick the Set implementation
> that
> > it wants to use? Why enforce it in StopFilter?
> >
> > I'm for:
> >
> > public StopFilter(TokenStream in, Set stopWords) {
> > super(in);
> > this.stopWords = stopWords;
> >
> >
> > Otis (didn't follow the discussion closely, sorry if I repeated
> > somebody else's words or if I'm way off) Gospodnetic
> >
> >
> >
> > --- Doug Cutting <[EMAIL PROTECTED]> wrote:
> >> [EMAIL PROTECTED] wrote:
> >>> - public StopFilter(TokenStream in, Set stopTable) {
> >>> + public StopFilter(TokenStream in, Set stopWords) {
> >>> super(in);
> >>> - table = stopTable;
> >>> + this.stopWords = new HashSet(stopWords);
> >>> }
> >>
> >> This always allocates a new HashSet, which, if the stop list is
> >> large,
> >> and documents are small, could impact performance.
> >>
> >> Perhaps we can replace this with something like:
> >>
> >> public StopFilter(TokenStream in, Set stopWords) {
> >> this(in, stopWords instanceof HashSet ? ((HashSet)stopWords)
> >> : new HashSet(stopWords));
> >> }
> >>
> >> and then add another constructor:
> >>
> >> private StopFilter(TokenStream in, HashSet stopWords) {
> >> super(in);
> >> this.stopWords = stopTable;
> >> }
> >>
> >> Also, if we want the implementation to always be a HashSet
> >> internally,
> >> for performance, we ought to declare the field to be a HashSet,
> no?
> >>
> >> The competing goals here are:
> >> 1. Not to expose publicly the implementation of the Set;
> >> 2. Not to copy the contents of the Set when folks pass the
> value
> >> of
> >> makeStopSet.
> >> 3. Use the most efficient implementation internally.
> >>
> >> I think the changes above meet all of these.
> >>
> >> Doug
> >
> >
> >
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