regexp: speed up by about 30%.
The code used interfaces in a pretty, pedagogical way but not efficiently.
Remove unnecessary interface code for significant speedups.
Before:
regexp.BenchmarkLiteral
1000000 2629 ns/op
regexp.BenchmarkNotLiteral 100000 18131 ns/op
regexp.BenchmarkMatchClass 100000 26647 ns/op
regexp.BenchmarkMatchClass_InRange 100000 27092 ns/op
regexp.BenchmarkReplaceAll 100000 27014 ns/op
After:
regexp.BenchmarkLiteral
1000000 2077 ns/op
regexp.BenchmarkNotLiteral 100000 13738 ns/op
regexp.BenchmarkMatchClass 100000 20418 ns/op
regexp.BenchmarkMatchClass_InRange 100000 20999 ns/op
regexp.BenchmarkReplaceAll 100000 21825 ns/op
There's likely more to do without major surgery, but this is a simple, significant step.
R=rsc
CC=golang-dev
https://golang.org/cl/
3572042