class IRB::Irb

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 and !@context.io.respond_to?(:auto_indent)
      unless ltype
        prompt_i = @context.prompt_i.nil? ? "" : @context.prompt_i
        ind = prompt(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
    @context.io.prompt
  end
  @scanner.set_input 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" if @context.prompting?
        end
      end
      l
    end
  end
  @scanner.configure_io(@context.io)
  @scanner.each_top_level_statement do |line, line_no|
    signal_status(:IN_EVAL) do
      begin
        # Assignment expression check should be done before evaluate_line to handle code like `a /2#/ if false; a = 1`
        is_assignment = assignment_expression?(line)
        evaluate_line(line, line_no)
        if @context.echo?
          if is_assignment
            if @context.echo_on_assignment?
              output_value(@context.echo_on_assignment? == :truncate)
            end
          else
            output_value
          end
        end
      rescue SystemExit, SignalException
        raise
      rescue Interrupt, Exception => exc
        handle_exception(exc)
        @context.workspace.local_variable_set(:_, exc)
      end
    end
  end
end