How do you escape characters in a lua-match query?

[ColinKennedy]

Context: I used :TSInstall comment to add comment highlighting and parsing.

I'd like comments in Python, for example, to light up if they end in a !, like this. And I'd like certain others lines to highlight differently if they end in ? (for example)

# This is a normal line
# But this line is important!
# Note: Maybe we should ask X person about the code below?
super_old_function()

I tried adding my own queries to do this, such as

("text" @text.danger @nospell
 (#lua-match? @text.danger "^.+\!$"))

("text" @text.note.question @nospell
 (#lua-match? @text.note.rare "^.+\?$"))

I've tried other varieties such as \!, [!], and anything else that I could think of to try to escape the ! and ? characters, nothing worked. I read through :help treesitter-predicate-lua-match? and the other areas but didn't see anything on this topic. Any advice on how to escape ! and ? to get the desired effect would be appreciated.

[clason]

:h lua-patterns

[ColinKennedy]

Your answer is ambiguous so I'm forced to interpret it to mean "I'll teach you how to fish (this answer)". Unfortunately, that's been hard for me to do.

Lua intentionally does not support regular expressions, instead it has limited
"patterns" |luaref-patterns| which avoid the performance pitfalls of extended
regex. Lua scripts can also use Vim regex via |vim.regex()|.

These examples use |string.match()| to demonstrate Lua patterns: >lua

    print(string.match("foo123bar123", "%d+"))
    -- 123
    print(string.match("foo123bar123", "[^%d]+"))
    -- foo
    print(string.match("foo123bar123", "[abc]+"))
    -- ba
    print(string.match("foo.bar", "%.bar"))
    -- .bar

Implies that "%" is the escape character however

("text" @text.danger @nospell
 (#lua-match? @text.danger "^.+%!$"))

("text" @text.note.rare @nospell
 (#lua-match? @text.note.rare "^.+%?$"))

Both do not work. So then what part of that :h message were you trying to bring attention to? The Lua intentionally does not support regular expressions, instead it has limited "patterns" part? Because ^ and $ are supported patterns. You can see them used in the same comment/highlights.scm e.g.

; Issue number (#123)
("text" @number
 (#lua-match? @number "^#[0-9]+$"))

And that query above works. And . seems to also work, just from some quick experimentation.

Maybe you were trying to point me actually to :h vim.pesc() where I would've gotten a direct answer to my question.

:lua print(vim.pesc("?")) which returns %?. However if %? is correctly escaped, it still doesn't explain why

("text" @text.note.rare @nospell
 (#lua-match? @text.note.rare "^.+%?$"))

does not work.

I'd like believe that you had the best of intentions while being indirect in your response but this is causing more confusion for me than anything. I would appreciate it if you could elaborate your response to give an answer to the original question.

I'd like comments in Python, for example, to light up if they end in a !, like this. And I'd like certain others lines to highlight differently if they end in ? (for example).

How would I write a query in order to do this? Thank you for your help in advance.

[ColinKennedy]

Worth noting that the expression + escape is working, for certain characters. For example

("text" @text.note.rare @nospell
 (#lua-match? @text.note.rare "^.+%$"))

This does work.

But changing to

("text" @text.note.rare @nospell
 (#lua-match? @text.note.rare "^.+%?"))

does not work

There's something invisible at play and it's hard to know what it is.