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 441
def eval_input
  exc = nil

  @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, exception: exc)
        output_value if @context.echo?
      rescue Interrupt => exc
      rescue SystemExit, SignalException
        raise
      rescue Exception => exc
      else
        exc = nil
        next
      end
      handle_exception(exc)
    end
  end
end

# File lib/irb.rb, line 508
def handle_exception(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

  if STDOUT.tty?
    attr = ATTR_TTY
    print "#{attr[1]}Traceback#{attr[]} (most recent call last):\n"
  else
    attr = ATTR_PLAIN
  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
      count += 1
      if attr == ATTR_TTY
        m = sprintf("%9d: from %s", count, m)
      else
        m = "\tfrom #{m}"
      end
      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
  if attr == ATTR_TTY
    unless lasts.empty?
      puts lasts.reverse
      printf "... %d levels...\n", levels if levels > 0
    end
    puts messages.reverse
  end
  m = exc.to_s.split(/\n/)
  print "#{attr[1]}#{exc.class} (#{attr[4]}#{m.shift}#{attr[0, 1]})#{attr[]}\n"
  puts m.map {|s| "#{attr[1]}#{s}#{attr[]}\n"}
  if attr == ATTR_PLAIN
    puts messages
    unless lasts.empty?
      puts lasts
      printf "... %d levels...\n", levels if levels > 0
    end
  end
  print "Maybe IRB bug!\n" if irb_bug
end

# File lib/irb.rb, line 690
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 418
def run(conf = IRB.conf)
  conf[:IRB_RC].call(context) if conf[:IRB_RC]
  conf[:MAIN_CONTEXT] = context

  trap("SIGINT") do
    signal_handle
  end

  begin
    catch(:IRB_EXIT) do
      eval_input
    end
  ensure
    conf[:AT_EXIT].each{|hook| hook.call}
  end
end

# File lib/irb.rb, line 619
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 641
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 609
def suspend_context(context)
  @context, back_context = context, @context
  begin
    yield back_context
  ensure
    @context = back_context
  end
end

# File lib/irb.rb, line 598
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 568
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 584
def suspend_workspace(workspace)
  @context.workspace, back_workspace = workspace, @context.workspace
  begin
    yield back_workspace
  ensure
    @context.workspace = back_workspace
  end
end