blevesearch/bleve — pull request #134 by Shugyousha (2014-12-23 14:42:32+00:00)
Title: Add a benchmark for the numeric facet builder and use sort.Sort in it (just like for the terms one) 

I am not 100% sure that the benchmark is measuring the right thing so some checking would be advised. In its current form it adds 10/100/1000 ranges to the range facet builder and then updates it with a very limited set of 4 prefix coded values over and over again. Afterwards it measures how long the Result() function takes to return its result.

If the benchmark is indeed mimicking real world uses, using the slice-based Result()-implementation is a net win just like with the term facet builder. Here are the numbers (on my i7 under Linux).

Old (using a list):
```
PASS
BenchmarkNumericFacet10 100000 14304 ns/op
BenchmarkNumericFacet100 10000 147730 ns/op
BenchmarkNumericFacet1000 300 4351645 ns/op
...
```

New (using sort.Sort):
```
PASS
BenchmarkNumericFacet10 200000 8603 ns/op
BenchmarkNumericFacet100 20000 73970 ns/op
BenchmarkNumericFacet1000 2000 782526 ns/op
...
```