Extended maintenance of Ruby 1.9.3 ended on February 23, 2015. Read more

In Files

  • irb.rb
  • irb/ext/multi-irb.rb

IRB::Irb

irb interpreter main routine

Attributes

context[R]
scanner[RW]

Public Class Methods

new(workspace = nil, input_method = nil, output_method = nil) click to toggle source
 
               # File irb.rb, line 98
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
            

Public Instance Methods

eval_input() click to toggle source
 
               # File irb.rb, line 109
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_atfer_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
            
inspect() click to toggle source
 
               # File irb.rb, line 314
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_value() click to toggle source
 
               # File irb.rb, line 310
def output_value
  printf @context.return_format, @context.inspect_last_value
end
            
prompt(prompt, ltype, indent, line_no) click to toggle source
 
               # File irb.rb, line 279
def prompt(prompt, ltype, indent, line_no)
  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 $1
        format("%" + $1 + "d", indent)
      else
        indent.to_s
      end
    when "n"
      if $1
        format("%" + $1 + "d", line_no)
      else
        line_no.to_s
      end
    when "%"
      "%"
    end
  end
  p
end
            
signal_handle() click to toggle source
 
               # File irb.rb, line 246
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) click to toggle source
 
               # File irb.rb, line 267
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) click to toggle source
 
               # File irb.rb, line 237
def suspend_context(context)
  @context, back_context = context, @context
  begin
    yield back_context
  ensure
    @context = back_context
  end
end
            
suspend_input_method(input_method) click to toggle source
 
               # File irb.rb, line 227
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) click to toggle source
 
               # File irb.rb, line 207
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) click to toggle source
 
               # File irb.rb, line 218
def suspend_workspace(workspace)
  @context.workspace, back_workspace = workspace, @context.workspace
  begin
    yield back_workspace
  ensure
    @context.workspace = back_workspace
  end
end
            

Commenting is here to help enhance the documentation. For example, code samples, or clarification of the documentation.

If you have questions about Ruby or the documentation, please post to one of the Ruby mailing lists. You will get better, faster, help that way.

If you wish to post a correction of the docs, please do so, but also file bug report so that it can be corrected for the next release. Thank you.

If you want to help improve the Ruby documentation, please visit Documenting-ruby.org.