Hi, I'm not sure if you've checked, but there is plenty of online documentation for Ruby. https://ruby-doc.org/core-3.0.1/String.html#method-i-encode https://ruby-doc.org/core-3.0.1/Array.html#method-i-pack On Sun, 21 Apr 2024 at 19:02, Information via ruby-talk <ruby-talk@ml.ruby-lang.org> wrote:
Hi,
How to reverse str.codepoints?
str.codepoints.reverse
how can I convert codepoints between UTF8 and UTF16 ? e.g: cp1 = [0xf0, 0x9f, 0x8f, 0xb3]; cp2 = [0xe2, 0x82, 0xac] #=> 0x20ac Could someone add UTF-8 to pack/unpack ? # seems output is UTF16 instead as UTF8 as doku says!
Those are arrays of bytes, not codepoints. A codepoint is usually transported as a single integer. The most logical way to deal with characters and codepoints is with strings, so I'd start by getting it back from an array of bytes to a string with the correct encoding metadata: str1 = cp1.pack('C*').force_encoding('UTF-8') #=> "🏳" str2 = cp2.pack('C*').force_encoding('UTF-8') #=> "€" Then you can convert to UTF-16 str1.encode('UTF-16').codepoints #=> [0xFEFF, 0x1F3F3] str2.encode('UTF-16').codepoints #=> [0xFEFF, 0x20AC] My question is: why? What are you trying to do? You seem to be partway down a rabbit hole and have maybe lost track of the actual goal you're trying to achieve?
How to show the US-Flag (star-flag as one graphical symbol), composed of [0x1f1fa, 0x1f1f8] ? # How to compose UTF-symbols consisting of more codepoints?
Emoji sequences (and other character sequences) are sequences of codepoints, so you have to transmit them as a sequence. I don't know what you're asking. [0x1f1fa, 0x1f1f8].pack 'U*' #=> "🇺🇸" Cheers -- Matthew Kerwin [he/him] https://matthew.kerwin.net.au/