class IRB::Irb

# File lib/irb.rb, line 428
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 442
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
        print exc.class, ": ", exc, "\n"
        if 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
        for m in exc.backtrace
          m = @context.workspace.filter_backtrace(m) unless irb_bug
          if m
            if messages.size < @context.back_trace_limit
              messages.push "\tfrom "+m
            else
              lasts.push "\tfrom "+m
              if lasts.size > @context.back_trace_limit
                lasts.shift
                levels += 1
              end
            end
          end
        end
        print messages.join("\n"), "\n"
        unless lasts.empty?
          printf "... %d levels...\n", levels if levels > 0
          print lasts.join("\n")
        end
        print "Maybe IRB bug!\n" if irb_bug
      end
      if $SAFE > 2
        abort "Error: irb does not work for $SAFE level higher than 2"
      end
    end
  end
end

# File lib/irb.rb, line 667
def inspect
  ary = []
  for iv in instance_variables
    case (iv = iv.to_s)
    when "@signal_status"
      ary.push format("%s=:%s", iv, @signal_status.id2name)
    when "@context"
      ary.push format("%s=%s", iv, eval(iv).__to_s__)
    else
      ary.push format("%s=%s", iv, eval(iv))
    end
  end
  format("#<%s: %s>", self.class, ary.join(", "))
end

# File lib/irb.rb, line 596
def signal_handle
  unless @context.ignore_sigint?
    print "\nabort!\n" if @context.verbose?
    exit
  end

  case @signal_status
  when :IN_INPUT
    print "^C\n"
    raise RubyLex::TerminateLineInput
  when :IN_EVAL
    IRB.irb_abort(self)
  when :IN_LOAD
    IRB.irb_abort(self, LoadAbort)
  when :IN_IRB
    # ignore
  else
    # ignore other cases as well
  end
end

# File lib/irb.rb, line 618
def signal_status(status)
  return yield if @signal_status == :IN_LOAD

  signal_status_back = @signal_status
  @signal_status = status
  begin
    yield
  ensure
    @signal_status = signal_status_back
  end
end

# File lib/irb.rb, line 586
def suspend_context(context)
  @context, back_context = context, @context
  begin
    yield back_context
  ensure
    @context = back_context
  end
end

# File lib/irb.rb, line 575
def suspend_input_method(input_method)
  back_io = @context.io
  @context.instance_eval{@io = input_method}
  begin
    yield back_io
  ensure
    @context.instance_eval{@io = back_io}
  end
end

# File lib/irb.rb, line 545
def suspend_name(path = nil, name = nil)
  @context.irb_path, back_path = path, @context.irb_path if path
  @context.irb_name, back_name = name, @context.irb_name if name
  begin
    yield back_path, back_name
  ensure
    @context.irb_path = back_path if path
    @context.irb_name = back_name if name
  end
end

# File lib/irb.rb, line 561
def suspend_workspace(workspace)
  @context.workspace, back_workspace = workspace, @context.workspace
  begin
    yield back_workspace
  ensure
    @context.workspace = back_workspace
  end
end