Class: IRB::Irb

Inherits:
Object show all
Defined in:
lib/irb.rb,
lib/irb/ext/multi-irb.rb

Constant Summary collapse

ASSIGNMENT_NODE_TYPES =
[
  # Local, instance, global, class, constant, instance, and index assignment:
  #   "foo = bar",
  #   "@foo = bar",
  #   "$foo = bar",
  #   "@@foo = bar",
  #   "::Foo = bar",
  #   "a::Foo = bar",
  #   "Foo = bar"
  #   "foo.bar = 1"
  #   "foo[1] = bar"
  :assign,

  # Operation assignment:
  #   "foo += bar"
  #   "foo -= bar"
  #   "foo ||= bar"
  #   "foo &&= bar"
  :opassign,

  # Multiple assignment:
  #   "foo, bar = 1, 2
  :massign,
]
ATTR_TTY =
"\e[%sm"
ATTR_PLAIN =
""

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(workspace = nil, input_method = nil) ⇒ Irb

Creates a new irb session


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# File 'lib/irb.rb', line 453

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

Instance Attribute Details

#contextObject (readonly)

Returns the current context of this irb session


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# File 'lib/irb.rb', line 478

def context
  @context
end

#scannerObject

The lexer used by this irb session


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# File 'lib/irb.rb', line 480

def scanner
  @scanner
end

Instance Method Details

#assignment_expression?(line) ⇒ Boolean

Returns:

  • (Boolean)

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# File 'lib/irb.rb', line 759

def assignment_expression?(line)
  # Try to parse the line and check if the last of possibly multiple
  # expressions is an assignment type.

  # If the expression is invalid, Ripper.sexp should return nil which will
  # result in false being returned. Any valid expression should return an
  # s-expression where the second selement of the top level array is an
  # array of parsed expressions. The first element of each expression is the
  # expression's type.
  verbose, $VERBOSE = $VERBOSE, nil
  result = ASSIGNMENT_NODE_TYPES.include?(Ripper.sexp(line)&.dig(1,-1,0))
  $VERBOSE = verbose
  result
end

#eval_inputObject

Evaluates input for this session.


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# File 'lib/irb.rb', line 483

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 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(@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.set_auto_indent(@context) if @context.auto_indent_mode

  @scanner.each_top_level_statement do |line, line_no|
    signal_status(:IN_EVAL) do
      begin
        line.untaint if RUBY_VERSION < '2.7'
        @context.evaluate(line, line_no, exception: exc)
        output_value if @context.echo? && (@context.echo_on_assignment? || !assignment_expression?(line))
      rescue Interrupt => exc
      rescue SystemExit, SignalException
        raise
      rescue Exception => exc
      else
        exc = nil
        next
      end
      handle_exception(exc)
    end
  end
end

#handle_exception(exc) ⇒ Object


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# File 'lib/irb.rb', line 554

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

#inspectObject

Outputs the local variables to this current session, including #signal_status and #context, using IRB::Locale.


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# File 'lib/irb.rb', line 744

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

#output_valueObject

:nodoc:


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# File 'lib/irb.rb', line 738

def output_value # :nodoc:
  printf @context.return_format, @context.inspect_last_value
end

#prompt(prompt, ltype, indent, line_no) ⇒ Object

:nodoc:


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# File 'lib/irb.rb', line 699

def prompt(prompt, ltype, indent, line_no) # :nodoc:
  p = prompt.dup
  p.gsub!(/%([0-9]+)?([a-zA-Z])/) do
    case $2
    when "N"
      @context.irb_name
    when "m"
      @context.main.to_s
    when "M"
      @context.main.inspect
    when "l"
      ltype
    when "i"
      if indent < 0
        if $1
          "-".rjust($1.to_i)
        else
          "-"
        end
      else
        if $1
          format("%" + $1 + "d", indent)
        else
          indent.to_s
        end
      end
    when "n"
      if $1
        format("%" + $1 + "d", line_no)
      else
        line_no.to_s
      end
    when "%"
      "%"
    end
  end
  p
end

#run(conf = IRB.conf) ⇒ Object


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# File 'lib/irb.rb', line 460

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

#signal_handleObject

Handler for the signal SIGINT, see Kernel#trap for more information.


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# File 'lib/irb.rb', line 665

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

#signal_status(status) ⇒ Object

Evaluates the given block using the given status.


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# File 'lib/irb.rb', line 687

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

#suspend_context(context) ⇒ Object

Evaluates the given block using the given context as the Context.


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# File 'lib/irb.rb', line 655

def suspend_context(context)
  @context, back_context = context, @context
  begin
    yield back_context
  ensure
    @context = back_context
  end
end

#suspend_input_method(input_method) ⇒ Object

Evaluates the given block using the given input_method as the Context#io.

Used by the irb commands source and irb_load, see [email protected]+Sessions for more information.


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# File 'lib/irb.rb', line 644

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

#suspend_name(path = nil, name = nil) ⇒ Object

Evaluates the given block using the given path as the Context#irb_path and name as the Context#irb_name.

Used by the irb command source, see [email protected]+Sessions for more information.


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# File 'lib/irb.rb', line 614

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

#suspend_workspace(workspace) ⇒ Object

Evaluates the given block using the given workspace as the Context#workspace.

Used by the irb command irb_load, see [email protected]+Sessions for more information.


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# File 'lib/irb.rb', line 630

def suspend_workspace(workspace)
  @context.workspace, back_workspace = workspace, @context.workspace
  begin
    yield back_workspace
  ensure
    @context.workspace = back_workspace
  end
end