bug#22763: 25.1.50; Feature Request -- A faster method to obtain line number at position.

[Stefan Monnier]

> So ... it's using the cache is only faster when we have monumentally
> long lines, since memchr is so fast?  And in buffers with lines with
> normal line lengths, it's 10x slower?  That sounds like a rather drastic
> trade-off.

Yes, the problem is when you have pathologically-long lines (typically,
when the whole file has virtually no \n in it, so lines can reach
multi-MB lengths).


        Stefan