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From Jason Rutherglen <jason.rutherg...@gmail.com>
Subject Re: Count of keys of an FST
Date Thu, 28 Jun 2012 13:32:48 GMT
I looked at the sources and didn't see a key count.

Thanks Dawid and Mike.

On Thu, Jun 28, 2012 at 6:37 AM, Michael McCandless <
lucene@mikemccandless.com> wrote:

> I believe node and arc count are stored, but not key count.  But check
> the sources to be sure!
>
> Mike McCandless
>
> http://blog.mikemccandless.com
>
> On Wed, Jun 27, 2012 at 4:53 PM, Dawid Weiss
> <dawid.weiss@cs.put.poznan.pl> wrote:
> > If you need the count with constant time then yes, you should store it
> > separately. You could also make a transducer that would store it at
> > the root node as side-effect of values associated with keys, but it's
> > kind of ugly.
> >
> > Please check the fst header though -- I'm not sure, maybe Mike wrote
> > it so that the node count/ keys count is in there.
> >
> > Dawid
> >
> > On Wed, Jun 27, 2012 at 10:50 PM, Jason Rutherglen
> > <jason.rutherglen@gmail.com> wrote:
> >> Sounds like I should just count as the keys are added and store the
> count
> >> separately.
> >>
> >> On Wed, Jun 27, 2012 at 3:48 PM, Dawid Weiss <
> dawid.weiss@cs.put.poznan.pl>
> >> wrote:
> >>>
> >>> I don't think there is one that you could use out of the box... but
> >>> maybe I'm wrong and it's stored in the header somewhere (don't have
> >>> the source in front of me).
> >>>
> >>> To calculate it by hand the worst case is that you'll need a recursive
> >>> traversal, which would mean O(number of stored states) with
> >>> intermediate count caches or O(number of keys) without any caches and
> >>> memory overhead (just recursive traversal).
> >>>
> >>> Dawid
> >>>
> >>> On Wed, Jun 27, 2012 at 10:36 PM, Jason Rutherglen
> >>> <jason.rutherglen@gmail.com> wrote:
> >>> > The FST class has a number of methods that return counts, which one
> >>> > returns
> >>> > the total number of keys that have been encoded into the FST?
> >>>
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