[ruby-core:118313] [Ruby master Feature#20576] Add MatchData#bytebegin and MatchData#byteend

Issue #20576 has been updated by shugo (Shugo Maeda).


matz (Yukihiro Matsumoto) wrote in #note-3:
> I understand the use-case. I agree with the addition of the feature, but =
I don't like the name. The names `bytebegin`, `byteend` are follow the `byt=
eindex` tradition, but it is very hard to read (especially `byteend`). Any =
other name suggestions?

I came up with names `begin_in_bytes` and `end_in_bytes`, but `byte_begin` =
/ `byte_end` suggested by Eregon may be better.


----------------------------------------
Feature #20576: Add MatchData#bytebegin and MatchData#byteend
https://bugs.ruby-lang.org/issues/20576#change-108822

* Author: shugo (Shugo Maeda)
* Status: Open
* Target version: 3.4
----------------------------------------
I'd like to propose MatchData#bytebegin and MatchData#byteend.
These methods are similar to MatchData#begin and MatchData#end, but returns=
 offsets in bytes instead of codepoints.

Pull request: https://github.com/ruby/ruby/pull/10973

One of the use cases is scanning strings: https://github.com/ruby/net-imap/=
pull/286/files
MatchData#byteend is faster than MatchData#byteoffset because there is no n=
eed to allocate an Array.
Here's a benchmark result:

```
voyager:ruby$ cat b.rb=20
require "benchmark"
require "strscan"

text =3D "=E3=81=82" * 100000

Benchmark.bmbm do |b|
  b.report("byteoffset(0)[1]") do
    pos =3D 0
    while text.byteindex(/\G./, pos)
      pos =3D $~.byteoffset(0)[1]
    end
  end

  b.report("byteend(0)") do
    pos =3D 0
    while text.byteindex(/\G./, pos)
      pos =3D $~.byteend(0)
    end
  end
end
voyager:ruby$ ./tool/runruby.rb b.rb          =20
Rehearsal ----------------------------------------------------
byteoffset(0)[1]   0.020558   0.000393   0.020951 (  0.020963)
byteend(0)         0.018149   0.000000   0.018149 (  0.018151)
------------------------------------------- total: 0.039100sec

                       user     system      total        real
byteoffset(0)[1]   0.020821   0.000000   0.020821 (  0.020822)
byteend(0)         0.017455   0.000000   0.017455 (  0.017455)
```




--=20
https://bugs.ruby-lang.org/