Use and honour xattr (extended attributes) text encoding

[gingerbeardman]

Proposal

Use xattr (extended attributes) on macOS to save/load text encoding with file.

BBEdit is the only editor I've found that already does this.

Also Chocolat should honours any keep any existing com.apple.TextEncoding value.

Background

• Text Encoding has to either be set manually, or guessed by scanning the file
• Both of these tasks take time

Benefits

• loading time can be reduced
• text encoding can be more persistent
• can still be changed and rewritten at any point

Details

debug command:
xattr -p -l com.apple.TextEncoding "/path/to/file.txt"

output:
file.txt
com.apple.TextEncoding: Shift_JIS;2561

to set xattr (from terminal):
xattr -w com.apple.TextEncoding "Shift_JIS;2561" "/path/to/file.txt"

References

these may help with implementation:

• obj-c: https://stackoverflow.com/questions/10374580/
• swift: https://github.com/okla/swift-xattr
• obj-c & swift (alt): https://developer.apple.com/library/content/qa/qa1719/_index.html
• node: https://github.com/LinusU/fs-xattr
• python: https://github.com/xattr/xattr