Which characters should be escaped in Vim regex for todo configuration?

[manoelpqueiroz]

Hi guys, I have been trying to tweak the configuration with the main goal of identifying [ ] as a todo in Markdown files. Basically, I am adapting Todo-Tree's Rust regex to the Vim regex for the pattern option of Todo-comments.

The Rust regex is as follows:

(//|--|#|<!--|;|/\*|^[ \t]*(-|\d+.))\s*(KEYWORDS)

So far, I have attempted to implement the following configuration with LazyVim, but :

return {
  "folke/todo-comments.nvim",
  opts = {
    signs = true,
    sign_priority = 8,
    keywords = {
      CHECKLIST = {
        icon = " ",
        color = "#39e673",
        alt = { "[ ]" }, -- With the "pending task" as an alt word, it should theoretically work
      },
      TODO = {
        icon = " ",
        color = "#e69b39",
      },
    highlight = {
      multiline = false,
      before = "",
      keyword = "bg",
      after = "fg",
      pattern = [[\(//\|--\|#\|;\|/\*\|^[ \t]*\(-\|\d+.\)\)\s*(KEYWORDS)\s*]], -- TODO This todo does not get highlighted in Lua if the pattern on the left is set
      --pattern = [[(//|--|#|;|/\*|^[ \t]*(-|\d+.))\s*(KEYWORDS)\s*]], -- TODO This todo also does not get highlighted if pattern set
      comments_only = false, -- This option
    },
  },
}

I believe the problem is that the Vim regex is not set up correctly, do you guys have any clue as to why it is failing to work?

Much appreciated.