spinoso_string::String::chars does not yield encoded strings

[lopopolo]

The 1-character strings yielded by String#chars and String#each_char should share the encoding of the source string.

MRI 3.3.0

$ irb
[3.3.0] > "abc".chars.map { _1.encoding }
=> [#<Encoding:UTF-8>, #<Encoding:UTF-8>, #<Encoding:UTF-8>]
[3.3.0] > "abc".b.chars.map { _1.encoding }
=> [#<Encoding:ASCII-8BIT>, #<Encoding:ASCII-8BIT>, #<Encoding:ASCII-8BIT>]
[3.3.0] > "你好".chars.length
=> 2
[3.3.0] > "你好".b.chars.length
=> 6
[3.3.0] > "你好".chars.map { _1.valid_encoding? }
=> [true, true]
[3.3.0] > "你好".b.chars.map { _1.valid_encoding? }
=> [true, true, true, true, true, true]

Artichoke

$ docker run -it docker.io/artichokeruby/artichoke:slim-bookworm-nightly airb
artichoke 0.1.0-pre.0 (2023-12-26 revision 7076) [x86_64-unknown-linux-gnu]
[rustc 1.72.0 (5680fa18f 2023-08-23) on x86_64-unknown-linux-gnu]
>>> "abc".chars.map { _1.encoding }
=> [#<Encoding:UTF-8>, #<Encoding:UTF-8>, #<Encoding:UTF-8>]
>>> "abc".b.chars.map { _1.encoding }
=> [#<Encoding:UTF-8>, #<Encoding:UTF-8>, #<Encoding:UTF-8>]
>>> "你好".chars.length
=> 2
>>> "你好".b.chars.length
=> 6
>>> "你好".chars.map { _1.valid_encoding? }
=> [true, true]
>>> "你好".b.chars.map { _1.valid_encoding? }
=> [false, false, false, false, false, false]