Wow, everyone's a cynic. Did you miss the part about the trigram index?
It sounds like you are replying to regexp1.html, not regexp4.html.
Re:How Google Code Search Worked
by _investigator on Friday January 20, 2012 @12:51AM
(#3488536)
No. You misread. I love Russ Cox's way of thinking and his continual generosity in sharing his work. I too use the Plan 9 base sed and grep. I'm cynical about the people who rave on about perl/javascript/python/ruby/whatever regexp, who derive some perverse joy in ridiculously complex RE and who often diss sed and all things old school as being slow or deficient in some way.
The original basic RE and extended RE (when backreferencing is not used) are significantly faster than implementations that most programmers traditionally rave about, e.g., Perl RE.
Tell me something I didn't know.
He thus used such 30 year old code as a model and easily topped the speeds of the built-in RE capabilities of today's popular scripting languages.
Common sense is underrated.