Method: Janeway::Functions#translate_iregex_to_ruby_regex

Defined in:
lib/janeway/functions.rb

#translate_iregex_to_ruby_regex(iregex, anchor: true) ⇒ Regexp

Convert IRegexp format to ruby regexp equivalent, following the instructions in rfc9485.

See Also:



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# File 'lib/janeway/functions.rb', line 13

def translate_iregex_to_ruby_regex(iregex, anchor: true)
  # * For any unescaped dots (.) outside character classes (first
  #   alternative of charClass production), replace the dot with [^\n\r].
  chars = iregex.chars
  in_char_class = false
  indexes = []
  chars.each_with_index do |char, i|
    case char
    when '[' then in_char_class = true
    when ']'
      in_char_class = false unless chars[i - 1] == '\\' # escaped ] does not close char class
    when '.'
      next if in_char_class || chars[i - 1] == '\\' # escaped dot

      indexes << i # replace this dot
    end
  end
  indexes.reverse_each do |i|
    chars[i] = '[^\n\r]'
  end

  # * Enclose the regexp in \A(?: and )\z.
  regex_str = anchor ? format('\A(?:%s)\z', chars.join) : chars.join
  Regexp.new(regex_str)
end