ack might be an example. It's Perl, not Python, and its author is on record as saying that performance isn't his goal. So it's a bit of a strained one. But yes, it's true, I don't know any other serious grep clone in a language like Python. This is why I hedged everything initially by saying that I know that absence of evidence isn't evidence of absence. :-) And in particular, I framed this as, "I would learn something," rather than, "this is objective fact." So long as my standard is my own experience, the hand wavy aspect of this works a bit better IMO.

> I do not know of a competitor who has put the care into such a tool to even try to measure, though.

Right. Like for example, I am certain enough about my claim that I would never even attempt to do it in the first place. I would guess that others think the same. With that said, people have written grep's in Python and the like, and last time I checked, they were very slow. But yeah, the "development effort" angle of this likely makes such tools inappropriate for a serious comparison to support my claim. But then again, if I'm right, the development effort required to make a Python grep be as fast as ripgrep is insurmountable.

> it all seems pretty hot spot optimizable to me

As long as we're okay with being hand wavy, then I would say that it's unlikely. Many of the optimizations in ripgrep have to do with amortizing allocation, and that kind of optimization is just nearly completely absent in a language like Python unless you drop down into C. This amortization principle is pervasive and applies as deep as regex internals to the code the simply prints ripgrep's output (which is in and of itself a complex beast and quite performance sensitive in workloads with lots of matches), and oodles of stuff inbetween.

> { And I love rg. Many thanks and no offense at all was intended! }

:-) No offense taken. This is by far the best convo I'm having in this HN post. Lol.

Note that I've made similar claims before. In the last one, there is a lot more data: https://news.ycombinator.com/item?id=17943509

> I do not know of a competitor who has put the care into such a tool to even try to measure, though.

As an aside, I'm the author of ack, and I would ask that folks not use the word "competitor" to describe different projects in the same space. Speaking for me/ack and burntsushi/ripgrep, there is absolutely no competition between us. We have different projects that do similar things, and neither of us is trying to best the other. We are each trying to make the best project we can for the needs we are looking to fill. ripgrep won't replace ack, ack won't replace ripgrep, and neither one will replace plain ol' grep. Each has its place.

I believe this so strongly that I created a [feature comparison chart](https://beyondgrep.com/feature-comparison/) comparing various greplike tools, and a related blog post I wrote on this: [The best open source project for someone might not be yours, and that's OK](https://blog.petdance.com/2018/01/02/the-best-open-source-pr...)