faulty handling of single-quoted strings

[dimbleby]

Hi, saw this appear in nvim-treesitter and took it for a spin.

Looks pretty good! But here's a small bug for you: single-quoted strings don't contain escape sequences.

eg see the examples at https://datatracker.ietf.org/doc/html/rfc7950#section-6.1.3.1

"\""  - string containing a double quote
'"'   - string containing a double quote
"\n"  - string containing a newline character
'\n'  - string containing a backslash followed
        by the character n

Maybe the fix is simply to remove this block? (but I don't know what I'm doing in treesitter, don't take my word for it).

While I'm here, I see that in your highlights query you use @string.escape for all sorts of things that aren't string escapes; whereas most of the neovim highlighters use it for an escape sequence - which this parser doesn't expose at all... Seems a bit back-to-front?

[Hubro]

Fixed, ref: #2 (comment)

[Hubro]

After skimming the RFC on YANG strings, it's clear that the parsing could be way better. It's been added to the TODO list in the README file.

[Hubro]

Fixed in #3