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Re: blead now has inversion lists for Unicode properties; ? Any Unicodeperformance benchmarks ?

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From:
Karl Williamson
Date:
January 16, 2012 09:24
Subject:
Re: blead now has inversion lists for Unicode properties; ? Any Unicodeperformance benchmarks ?
Message ID:
4F145D3C.4030402@khwilliamson.com
On 01/16/2012 10:12 AM, Nicholas Clark wrote:
> On Fri, Jan 13, 2012 at 12:09:30PM -0700, Karl Williamson wrote:
>> I have pushed to blead a series of commits that now use inversion lists
>> to store Unicode binary properties, as Jarkko has long advocated.
>
> Thanks
>
>> There are a number of changes and a number of implications, all
>> hopefully invisible to the end-user except potential performance
>> improvements.
>>
>> Inversion lists allow for a binary search instead of linear.  As one of
>> the commits details, a program that on my box took 97 seconds now takes
>> 1.5.  However, this was carefully constructed to be worst case.
>> Programs that have significant amounts of ASCII or Latin1 data take much
>> less time in the old scheme because those are at the beginning of binary
>> searches.
>
> I presume you meant "at the beginning of linear searches"
>
> Nicholas Clark
>

Yes,  and in reading  this excerpt of mine, I see it could be 
misconstrued.  I meant that under the old scheme ASCII and Latin1 data 
is fast because it is at the beginning of the linear searches.  I did 
not mean that the old scheme is faster than the new on this data; though 
there are certainly cases where that might be marginally true.

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