ext)
              if ext == 'md' then
                return 'markdown'
              elseif ext == 'rst' then
                return 'rst'
              end
            end,
          },
        })
<

    To add a fallback match on contents, use >lua
        vim.filetype.add {
          pattern = {
            ['.*'] = {
              function(path, bufnr)
                local content = vim.api.nvim_buf_get_lines(bufnr, 0, 1, false)[1] or ''
                if vim.regex([[^#!.*\\<mine\\>]]):match_str(content) ~= nil then
                  return 'mine'
                elseif vim.regex([[\\<drawing\\>]]):match_str(content) ~= nil then
                  return 'drawing'
                end
              end,
              { priority = -math.huge },
            },
          },
        }
<

    Parameters: ~
      • {filetypes}  (`table`) A table containing new filetype maps (see
                     example).
                     • {pattern}? (`vim.filetype.mapping`)
                     • {extension}? (`vim.filetype.mapping`)
                     • {filename}? (`vim.filetype.mapping`)

                                                   *vim.filetype.get_option()*
vim.filetype.get_option({filetype}, {option})
    Get the default option value for a {filetype}.

    The returned value is what would be set in a new buffer after 'filetype'
    is set, meaning it should respect all FileType autocmds and ftplugin
    files.

    Example: >lua
        vim.filetype.get_option('vim', 'commentstring')
<

    Note: this uses |nvim_get_option_value()| but caches the result. This
    means |ftplugin| and |FileType| autocommands are only triggered once and
    may not reflect later changes.

    Attributes: ~
        Since: 0.9.0

    Parameters: ~
      • {filetype}  (`string`) Filetype
      • {option}    (`string`) Option name

    Return: ~
        (`string|boolean|integer`) Option value

vim.filetype.match({args})                              *vim.filetype.match()*
    Perform filetype detection.

    The filetype can be detected using one of three methods:
    1. Using an existing buffer
    2. Using only a file name
    3. Using only file contents

    Of these, option 1 provides the most accurate result as it uses both the
    buffer's filename and (optionally) the buffer contents. Options 2 and 3
    can be used without an existing buffer, but may not always provide a match
    in cases where the filename (or contents) cannot unambiguously determine
    the filetype.

    Each of the three options is specified using a key to the single argument
    of this function. Example: >lua
        -- Using a buffer number
        vim.filetype.match({ buf = 42 })

        -- Override the filename of the given buffer
        vim.filetype.match({ buf = 42, filename = 'foo.c' })

        -- Using a filename without a buffer
        vim.filetype.match({ filename = 'main.lua' })

        -- Using file contents
        vim.filetype.match({ contents = {'#!/usr/bin/env bash'} })
<

    Parameters: ~
      • {args}  (`table`) Table specifying which matching strategy to use.
                Accepted keys are:
                • {buf}? (`integer`) Buffer number to use for matching.
                  Mutually exclusive with {contents}
                • {filename}? (`string`) Filename to use for matching. When
                  {buf} is given, defaults to the filename of the given buffer
                  number. The file need not actually exist in the filesystem.
                  When used without {buf} only the name of the file is used
                  for filetype matching. This may result in failure to detect
                  the filetype in cases where the filename alone is not enough
                  to disambiguate the filetype.
                • {contents}? (`string[]`) An array of lines representing file
                  contents to use for matching. Can be used with {filename}.
                  Mutually exclusive with {buf}.

    Return (multiple):