Module: IRB::Color

# File 'lib/irb/color.rb', line 149

def supported?
  return @supported if defined?(@supported)
  @supported = Ripper::Lexer::Elem.method_defined?(:state)
end

# File 'lib/irb/color.rb', line 101

def colorize(text, seq)
  return text unless colorable?
  seq = seq.map { |s| "\e[#{const_get(s)}m" }.join('')
  "#{seq}#{text}#{clear}"
end

# File 'lib/irb/color.rb', line 110

def colorize_code(code, complete: true)
  return code unless colorable?

  symbol_state = SymbolState.new
  colored = +''
  length = 0

  scan(code, allow_last_error: !complete) do |token, str, expr|
    in_symbol = symbol_state.scan_token(token)
    str.each_line do |line|
      line = Reline::Unicode.escape_for_print(line)
      if seq = dispatch_seq(token, expr, line, in_symbol: in_symbol)
        colored << seq.map { |s| "\e[#{s}m" }.join('')
        colored << line.sub(/\Z/, clear)
      else
        colored << line
      end
    end
    length += str.bytesize
  end

  # give up colorizing incomplete Ripper tokens
  if length != code.bytesize
    return Reline::Unicode.escape_for_print(code)
  end

  colored
end

# File 'lib/irb/color.rb', line 186

def dispatch_seq(token, expr, str, in_symbol:)
  if token == :on_parse_error or token == :compile_error
    TOKEN_SEQ_EXPRS[token][0]
  elsif in_symbol
    [YELLOW]
  elsif TOKEN_KEYWORDS.fetch(token, []).include?(str)
    [CYAN, BOLD]
  elsif (seq, exprs = TOKEN_SEQ_EXPRS[token]; (expr & (exprs || 0)) != 0)
    seq
  else
    nil
  end
end

# File 'lib/irb/color.rb', line 75

def inspect_colorable?(obj, seen: {}.compare_by_identity)
  case obj
  when String, Symbol, Regexp, Integer, Float, FalseClass, TrueClass, NilClass
    true
  when Hash
    without_circular_ref(obj, seen: seen) do
      obj.all? { |k, v| inspect_colorable?(k, seen: seen) && inspect_colorable?(v, seen: seen) }
    end
  when Array
    without_circular_ref(obj, seen: seen) do
      obj.all? { |o| inspect_colorable?(o, seen: seen) }
    end
  when Range
    inspect_colorable?(obj.begin, seen: seen) && inspect_colorable?(obj.end, seen: seen)
  when Module
    !obj.name.nil?
  else
    false
  end
end

# File 'lib/irb/color.rb', line 154

def scan(code, allow_last_error:)
  pos = [1, 0]

  verbose, $VERBOSE = $VERBOSE, nil
  RubyLex.compile_with_errors_suppressed(code) do |inner_code, line_no|
    lexer = Ripper::Lexer.new(inner_code, '(ripper)', line_no)
    if lexer.respond_to?(:scan) # Ruby 2.7+
      lexer.scan.each do |elem|
        str = elem.tok
        next if allow_last_error and /meets end of file|unexpected end-of-input/ =~ elem.message
        next if ([elem.pos[0], elem.pos[1] + str.bytesize] <=> pos) <= 0

        str.each_line do |line|
          if line.end_with?("\n")
            pos[0] += 1
            pos[1] = 0
          else
            pos[1] += line.bytesize
          end
        end

        yield(elem.event, str, elem.state)
      end
    else
      lexer.parse.each do |elem|
        yield(elem.event, elem.tok, elem.state)
      end
    end
  end
  $VERBOSE = verbose
end

# File 'lib/irb/color.rb', line 141

def without_circular_ref(obj, seen:, &block)
  return false if seen.key?(obj)
  seen[obj] = true
  block.call
ensure
  seen.delete(obj)
end