module IRB::Color - Documentation for Ruby 3.3

# module IRB::Color

### Constants

ALL

  A constant of all-bit 1 to match any Ripper’s state in dispatch_seq

BLACK
BLUE
BOLD
CLEAR
CYAN
ERROR_TOKENS
GREEN
MAGENTA
RED
REVERSE
TOKEN_KEYWORDS
TOKEN_SEQ_EXPRS

  Following pry’s colors where possible, but sometimes having a compromise like making backtick and regexp as red (string’s color, because they’re sharing tokens).

UNDERLINE
WHITE
YELLOW

### Public Class Methods

clear(colorable: colorable?) click to toggle source

    # File lib/irb/color.rb, line 114
    def clear(colorable: colorable?)
      return '' unless colorable
      "\e[#{CLEAR}m"
    end

colorable?() click to toggle source

    # File lib/irb/color.rb, line 81
    def colorable?
      supported = $stdout.tty? && (/mswin|mingw/.match?(RUBY_PLATFORM) || (ENV.key?('TERM') && ENV['TERM'] != 'dumb'))

      # because ruby/debug also uses irb's color module selectively,
      # irb won't be activated in that case.
      if IRB.respond_to?(:conf)
        supported && !!IRB.conf.fetch(:USE_COLORIZE, true)
      else
        supported
      end
    end

colorize(text, seq, colorable: colorable?) click to toggle source

    # File lib/irb/color.rb, line 119
    def colorize(text, seq, colorable: colorable?)
      return text unless colorable
      seq = seq.map { |s| "\e[#{const_get(s)}m" }.join('')
      "#{seq}#{text}#{clear(colorable: colorable)}"
    end

colorize_code(code, complete: true, ignore_error: false, colorable: colorable?, local_variables: []) click to toggle source

If ‘complete` is false (code is incomplete), this does not warn compile_error. This option is needed to avoid warning a user when the compile_error is happening because the input is not wrong but just incomplete.

    # File lib/irb/color.rb, line 128
    def colorize_code(code, complete: true, ignore_error: false, colorable: colorable?, local_variables: [])
      return code unless colorable

      symbol_state = SymbolState.new
      colored = +''
      lvars_code = RubyLex.generate_local_variables_assign_code(local_variables)
      code_with_lvars = lvars_code ? "#{lvars_code}\n#{code}" : code

      scan(code_with_lvars, allow_last_error: !complete) do |token, str, expr|
        # handle uncolorable code
        if token.nil?
          colored << Reline::Unicode.escape_for_print(str)
          next
        end

        # IRB::ColorPrinter skips colorizing fragments with any invalid token
        if ignore_error && ERROR_TOKENS.include?(token)
          return Reline::Unicode.escape_for_print(code)
        end

        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(colorable: colorable))
          else
            colored << line
          end
        end
      end

      if lvars_code
        raise "#{lvars_code.dump} should have no \\n" if lvars_code.include?("\n")
        colored.sub!(/\A.+\n/, '') # delete_prefix lvars_code with colors
      end
      colored
    end

inspect_colorable?(obj, seen: {}.compare_by_identity) click to toggle source

    # File lib/irb/color.rb, line 93
    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

### Private Class Methods

dispatch_seq(token, expr, str, in_symbol:) click to toggle source

    # File lib/irb/color.rb, line 213
    def dispatch_seq(token, expr, str, in_symbol:)
      if ERROR_TOKENS.include?(token)
        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

scan(code, allow_last_error:) { |nil, byteslice, nil| ... } click to toggle source

    # File lib/irb/color.rb, line 177
    def scan(code, allow_last_error:)
      verbose, $VERBOSE = $VERBOSE, nil
      RubyLex.compile_with_errors_suppressed(code) do |inner_code, line_no|
        lexer = Ripper::Lexer.new(inner_code, '(ripper)', line_no)
        byte_pos = 0
        line_positions = [0]
        inner_code.lines.each do |line|
          line_positions << line_positions.last + line.bytesize
        end

        on_scan = proc do |elem|
          start_pos = line_positions[elem.pos[0] - 1] + elem.pos[1]

          # yield uncolorable code
          if byte_pos < start_pos
            yield(nil, inner_code.byteslice(byte_pos...start_pos), nil)
          end

          if byte_pos <= start_pos
            str = elem.tok
            yield(elem.event, str, elem.state)
            byte_pos = start_pos + str.bytesize
          end
        end

        lexer.scan.each do |elem|
          next if allow_last_error and /meets end of file|unexpected end-of-input/ =~ elem.message
          on_scan.call(elem)
        end
        # yield uncolorable DATA section
        yield(nil, inner_code.byteslice(byte_pos...inner_code.bytesize), nil) if byte_pos < inner_code.bytesize
      end
    ensure
      $VERBOSE = verbose
    end

without_circular_ref(obj, seen:, &block) click to toggle source

    # File lib/irb/color.rb, line 169
    def without_circular_ref(obj, seen:, &block)
      return false if seen.key?(obj)
      seen[obj] = true
      block.call
    ensure
      seen.delete(obj)
    end