Class: IRB::Irb

# File 'lib/irb.rb', line 409

def initialize(workspace = nil, input_method = nil, output_method = nil)
  @context = Context.new(self, workspace, input_method, output_method)
  @context.main.extend ExtendCommandBundle
  @signal_status = :IN_IRB

  @scanner = RubyLex.new
  @scanner.exception_on_syntax_error = false
end

# File 'lib/irb.rb', line 436

attr_reader :context

# File 'lib/irb.rb', line 441

def eval_input
  @scanner.set_prompt do
    |ltype, indent, continue, line_no|
    if ltype
      f = @context.prompt_s
    elsif continue
      f = @context.prompt_c
    elsif indent > 0
      f = @context.prompt_n
    else
      f = @context.prompt_i
    end
    f = "" unless f
    if @context.prompting?
      @context.io.prompt = p = prompt(f, ltype, indent, line_no)
    else
      @context.io.prompt = p = ""
    end
    if @context.auto_indent_mode
      unless ltype
        ind = prompt(@context.prompt_i, ltype, indent, line_no)[/.*\z/].size +
          indent * 2 - p.size
        ind += 2 if continue
        @context.io.prompt = p + " " * ind if ind > 0
      end
    end
  end

  @scanner.set_input(@context.io) do
    signal_status(:IN_INPUT) do
      if l = @context.io.gets
        print l if @context.verbose?
      else
        if @context.ignore_eof? and @context.io.readable_after_eof?
          l = "\n"
          if @context.verbose?
            printf "Use \"exit\" to leave %s\n", @context.ap_name
          end
        else
          print "\n"
        end
      end
      l
    end
  end

  @scanner.each_top_level_statement do |line, line_no|
    signal_status(:IN_EVAL) do
      begin
        line.untaint
        @context.evaluate(line, line_no)
        output_value if @context.echo?
        exc = nil
      rescue Interrupt => exc
      rescue SystemExit, SignalException
        raise
      rescue Exception => exc
      end
      if exc
        if exc.backtrace && exc.backtrace[0] =~ /irb(2)?(\/.*|-.*|\.rb)?:/ && exc.class.to_s !~ /^IRB/ &&
            !(SyntaxError === exc)
          irb_bug = true
        else
          irb_bug = false
        end

        messages = []
        lasts = []
        levels = 0
        if exc.backtrace
          count = 0
          exc.backtrace.each do |m|
            m = @context.workspace.filter_backtrace(m) or next unless irb_bug
            m = sprintf("%9d: from %s", (count += 1), m)
            if messages.size < @context.back_trace_limit
              messages.push(m)
            elsif lasts.size < @context.back_trace_limit
              lasts.push(m).shift
              levels += 1
            end
          end
        end
        attr = STDOUT.tty? ? ATTR_TTY : ATTR_PLAIN
        print "#{attr[1]}Traceback#{attr[]} (most recent call last):\n"
        unless lasts.empty?
          puts lasts.reverse
          printf "... %d levels...\n", levels if levels > 0
        end
        puts messages.reverse
        messages = exc.to_s.split(/\n/)
        print "#{attr[1]}#{exc.class} (#{attr[4]}#{messages.shift}#{attr[0, 1]})#{attr[]}\n"
        puts messages.map {|s| "#{attr[1]}#{s}#{attr[]}\n"}
        print "Maybe IRB bug!\n" if irb_bug
      end
    end
  end
end