Defines a function with the given name that takes a list of tokens and divides matching delimiters into groups.

Takes as arguments a name for the function (must be an atom) and a list containing the patterns describing the matching groups.

Examples

# Extracted from the default elixir lexer that ships with ExDoc
defgroupmatcher :match_groups, [
  # Match opening and closing parenthesis
  parentheses: [
    open: [[{:punctuation, %{language: :elixir}, "("}]],
    close: [[{:punctuation, %{language: :elixir}, ")"}]]
  ],

  # Match more complex delimiters, but still an open and close delimiter
  fn_end: [
    open: [[{:keyword, %{language: :elixir}, "fn"}]],
    close: [[{:keyword, %{language: :elixir}, "end"}]]
  ]

  # Match delimiters with middle components
  do_end: [
    open: [
      [{:keyword, %{language: :elixir}, "do"}]
    ],
    middle: [
      [{:keyword, %{language: :elixir}, "else"}],
      [{:keyword, %{language: :elixir}, "catch"}],
      [{:keyword, %{language: :elixir}, "rescue"}],
      [{:keyword, %{language: :elixir}, "after"}]
    ],
    close: [
      [{:keyword, %{language: :elixir}, "end"}]
    ]
  ]
]

Returns a random prefix for group ids in an HTML file.

This is useful to avoid collisions. The group ids should be unique for a certain HTML document, and the easiest way of guaranteeing it is by generating long random prefixes.