At first I thought simply changing the regex might help, but then I
found more and more differences between Mastodon and Tusky, so I decided
to reimplement the thing. I added 74 testcases that I all compared to
Mastodon to make sure they are correct.
On an Fairphone 4 the new implementation is faster, on an Samsung Galaxy
Tab S3 slower.
Testcases for the benchmark:
```
test of a status with #one hashtag http
```
```
test
http:// #hashtag https://connyduck.at/http://example.org
this is a #test
and this is a @mention@test.com @test @test@test456@test.com
```
```
@mention@test.social Just your ordinary mention with a hashtag
#test
```
```
@mention@test.social Just your ordinary mention with a url
https://riot.im/app/#/room/#Tusky:matrix.org
```
FP4:
```
11.159 ns 15 allocs Benchmark.new_1
119.701 ns 43 allocs Benchmark.new_2
21.895 ns 24 allocs Benchmark.new_3
87.512 ns 32 allocs Benchmark.new_4
16.592 ns 46 allocs Benchmark.old_1
134.381 ns 169 allocs Benchmark.old_2
28.355 ns 68 allocs Benchmark.old_3
45.221 ns 77 allocs Benchmark.old_4
```
SGT3:
```
43,785 ns 18 allocs Benchmark.new_1
446,074 ns 43 allocs Benchmark.new_2
78,802 ns 26 allocs Benchmark.new_3
315,478 ns 32 allocs Benchmark.new_4
42,186 ns 45 allocs Benchmark.old_1
353,570 ns 157 allocs Benchmark.old_2
72,376 ns 66 allocs Benchmark.old_3
122,985 ns 74 allocs Benchmark.old_4
```
benchmark code is here: https://github.com/tuskyapp/tusky-span-benchmark
closes https://github.com/tuskyapp/Tusky/issues/4425