class IRB::Context

A class that wraps the current state of the irb session, including the configuration of IRB.conf.

Attributes

A copy of the default IRB.conf[:AP_NAME]

Can be either the default IRB.conf[:AUTO_INDENT], or the mode set by prompt_mode=

To disable auto-indentation in irb:

IRB.conf[:AUTO_INDENT] = false

irb_context.auto_indent_mode = false

IRB.CurrentContext.auto_indent_mode = false

See Configuration at IRB for more information.

back_trace_limit [RW]

The limit of backtrace lines displayed as top n and tail n.

The default value is 16.

Can also be set using the --back-trace-limit command line option.

See Command line options at IRB for more command line options.

command_aliases [RW]

User-defined IRB command aliases

echo [RW]

Whether to echo the return value to output or not.

Uses IRB.conf[:ECHO] if available, or defaults to true.

puts "hello"
# hello
#=> nil
IRB.CurrentContext.echo = false
puts "omg"
# omg

echo? [RW]

Whether to echo the return value to output or not.

Uses IRB.conf[:ECHO] if available, or defaults to true.

puts "hello"
# hello
#=> nil
IRB.CurrentContext.echo = false
puts "omg"
# omg

echo_on_assignment [RW]

Whether to echo for assignment expressions.

If set to false, the value of assignment will not be shown.

If set to true, the value of assignment will be shown.

If set to :truncate, the value of assignment will be shown and truncated.

It defaults to :truncate.

a = "omg"
#=> omg

a = "omg" * 10
#=> omgomgomgomgomgomgomg...

IRB.CurrentContext.echo_on_assignment = false
a = "omg"

IRB.CurrentContext.echo_on_assignment = true
a = "omg" * 10
#=> omgomgomgomgomgomgomgomgomgomg

To set the behaviour of showing on assignment in irb:

IRB.conf[:ECHO_ON_ASSIGNMENT] = :truncate or true or false

irb_context.echo_on_assignment = :truncate or true or false

IRB.CurrentContext.echo_on_assignment = :truncate or true or false

echo_on_assignment? [RW]

Whether to echo for assignment expressions.

If set to false, the value of assignment will not be shown.

If set to true, the value of assignment will be shown.

If set to :truncate, the value of assignment will be shown and truncated.

It defaults to :truncate.

a = "omg"
#=> omg

a = "omg" * 10
#=> omgomgomgomgomgomgomg...

IRB.CurrentContext.echo_on_assignment = false
a = "omg"

IRB.CurrentContext.echo_on_assignment = true
a = "omg" * 10
#=> omgomgomgomgomgomgomgomgomgomg

To set the behaviour of showing on assignment in irb:

IRB.conf[:ECHO_ON_ASSIGNMENT] = :truncate or true or false

irb_context.echo_on_assignment = :truncate or true or false

IRB.CurrentContext.echo_on_assignment = :truncate or true or false

eval_history [R]

The command result history limit. This method is not available until eval_history= was called with non-nil value (directly or via setting IRB.conf[:EVAL_HISTORY] in .irbrc).

extra_doc_dirs [RW]

Specify the installation locations of the ri file to be displayed in the document dialog.

ignore_eof [RW]

Whether ^D (control-d) will be ignored or not.

If set to false, ^D will quit irb.

ignore_eof? [RW]

Whether ^D (control-d) will be ignored or not.

If set to false, ^D will quit irb.

ignore_sigint [RW]

Whether ^C (control-c) will be ignored or not.

If set to false, ^C will quit irb.

If set to true,

during input: cancel input then return to top level.
during execute: abandon current execution.

ignore_sigint? [RW]

Whether ^C (control-c) will be ignored or not.

If set to false, ^C will quit irb.

If set to true,

during input: cancel input then return to top level.
during execute: abandon current execution.

inspect_mode [R]

A copy of the default IRB.conf[:INSPECT_MODE]

io [RW]

The current input method.

Can be either StdioInputMethod, ReadlineInputMethod, RelineInputMethod, FileInputMethod or other specified when the context is created. See ::new for more # information on input_method.

irb [RW]

Current irb session.

irb_name [RW]

Can be either name from IRB.conf[:IRB_NAME], or the number of the current job set by JobManager, such as irb#2

irb_path [RW]

Can be either the irb_name surrounded by parenthesis, or the input_method passed to Context.new

last_value [R]

The return value of the last statement evaluated.

load_modules [RW]

A copy of the default IRB.conf[:LOAD_MODULES]

newline_before_multiline_output [RW]

Whether a newline is put before multiline output.

Uses IRB.conf[:NEWLINE_BEFORE_MULTILINE_OUTPUT] if available, or defaults to true.

"abc\ndef"
#=>
abc
def
IRB.CurrentContext.newline_before_multiline_output = false
"abc\ndef"
#=> abc
def

newline_before_multiline_output? [RW]

Whether a newline is put before multiline output.

Uses IRB.conf[:NEWLINE_BEFORE_MULTILINE_OUTPUT] if available, or defaults to true.

"abc\ndef"
#=>
abc
def
IRB.CurrentContext.newline_before_multiline_output = false
"abc\ndef"
#=> abc
def

prompt_c [RW]

IRB prompt for continuated statement. (e.g. immediately after an if)

See Customizing the IRB Prompt at IRB for more information.

prompt_i [RW]

Standard IRB prompt.

See Customizing the IRB Prompt at IRB for more information.

prompt_mode [R]

A copy of the default IRB.conf[:PROMPT_MODE]

prompt_n [RW]

See Customizing the IRB Prompt at IRB for more information.

prompt_s [RW]

IRB prompt for continuated strings.

See Customizing the IRB Prompt at IRB for more information.

rc [RW]

A copy of the default IRB.conf[:RC]

rc? [RW]

A copy of the default IRB.conf[:RC]

return_format [RW]

The format of the return statement, set by prompt_mode= using the :RETURN of the mode passed to set the current prompt_mode.

thread [R]

The current thread in this context.

use_autocomplete [R]

Whether colorization is enabled or not.

A copy of the default IRB.conf[:USE_AUTOCOMPLETE]

use_autocomplete? [R]

Whether colorization is enabled or not.

A copy of the default IRB.conf[:USE_AUTOCOMPLETE]

use_multiline [R]

Whether multiline editor mode is enabled or not.

A copy of the default IRB.conf[:USE_MULTILINE]

use_multiline? [R]

Whether multiline editor mode is enabled or not.

A copy of the default IRB.conf[:USE_MULTILINE]

use_readline [R]

Whether singleline editor mode is enabled or not.

A copy of the default IRB.conf[:USE_SINGLELINE]

use_readline? [R]

Whether singleline editor mode is enabled or not.

A copy of the default IRB.conf[:USE_SINGLELINE]

use_reline [R]

Whether multiline editor mode is enabled or not.

A copy of the default IRB.conf[:USE_MULTILINE]

use_reline? [R]

Whether multiline editor mode is enabled or not.

A copy of the default IRB.conf[:USE_MULTILINE]

use_singleline [R]

Whether singleline editor mode is enabled or not.

A copy of the default IRB.conf[:USE_SINGLELINE]

use_singleline? [R]

Whether singleline editor mode is enabled or not.

A copy of the default IRB.conf[:USE_SINGLELINE]

use_tracer [R]

Whether Tracer is used when evaluating statements in this context.

See lib/tracer.rb for more information.

use_tracer? [R]

Whether Tracer is used when evaluating statements in this context.

See lib/tracer.rb for more information.

verbose [RW]

Whether verbose messages are displayed or not.

A copy of the default IRB.conf[:VERBOSE]

workspace [RW]

WorkSpace in the current context.

workspace_home [R]

The toplevel workspace, see home_workspace

Public Class Methods

new (irb, workspace = nil, input_method = nil)

Creates a new IRB context.

The optional input_method argument:

nil: uses stdin or Reline or Readline
String: uses a File
other: uses this as InputMethod

# File lib/irb/context.rb, line 28
    def initialize(irb, workspace = nil, input_method = nil)
      @irb = irb
      if workspace
        @workspace = workspace
      else
        @workspace = WorkSpace.new
      end
      @thread = Thread.current

      # copy of default configuration
      @ap_name = IRB.conf[:AP_NAME]
      @rc = IRB.conf[:RC]
      @load_modules = IRB.conf[:LOAD_MODULES]

      if IRB.conf.has_key?(:USE_SINGLELINE)
        @use_singleline = IRB.conf[:USE_SINGLELINE]
      elsif IRB.conf.has_key?(:USE_READLINE) # backward compatibility
        @use_singleline = IRB.conf[:USE_READLINE]
      else
        @use_singleline = nil
      end
      if IRB.conf.has_key?(:USE_MULTILINE)
        @use_multiline = IRB.conf[:USE_MULTILINE]
      elsif IRB.conf.has_key?(:USE_RELINE) # backward compatibility
        warn <<~MSG.strip
          USE_RELINE is deprecated, please use USE_MULTILINE instead.
        MSG
        @use_multiline = IRB.conf[:USE_RELINE]
      elsif IRB.conf.has_key?(:USE_REIDLINE)
        warn <<~MSG.strip
          USE_REIDLINE is deprecated, please use USE_MULTILINE instead.
        MSG
        @use_multiline = IRB.conf[:USE_REIDLINE]
      else
        @use_multiline = nil
      end
      @use_autocomplete = IRB.conf[:USE_AUTOCOMPLETE]
      @verbose = IRB.conf[:VERBOSE]
      @io = nil

      self.inspect_mode = IRB.conf[:INSPECT_MODE]
      self.use_tracer = IRB.conf[:USE_TRACER] if IRB.conf[:USE_TRACER]
      self.use_loader = IRB.conf[:USE_LOADER] if IRB.conf[:USE_LOADER]
      self.eval_history = IRB.conf[:EVAL_HISTORY] if IRB.conf[:EVAL_HISTORY]

      @ignore_sigint = IRB.conf[:IGNORE_SIGINT]
      @ignore_eof = IRB.conf[:IGNORE_EOF]

      @back_trace_limit = IRB.conf[:BACK_TRACE_LIMIT]

      self.prompt_mode = IRB.conf[:PROMPT_MODE]

      if IRB.conf[:SINGLE_IRB] or !defined?(IRB::JobManager)
        @irb_name = IRB.conf[:IRB_NAME]
      else
        @irb_name = IRB.conf[:IRB_NAME]+"#"+IRB.JobManager.n_jobs.to_s
      end
      @irb_path = "(" + @irb_name + ")"

      case input_method
      when nil
        @io = nil
        case use_multiline?
        when nil
          if STDIN.tty? && IRB.conf[:PROMPT_MODE] != :INF_RUBY && !use_singleline?
            # Both of multiline mode and singleline mode aren't specified.
            @io = RelineInputMethod.new
          else
            @io = nil
          end
        when false
          @io = nil
        when true
          @io = RelineInputMethod.new
        end
        unless @io
          case use_singleline?
          when nil
            if (defined?(ReadlineInputMethod) && STDIN.tty? &&
                IRB.conf[:PROMPT_MODE] != :INF_RUBY)
              @io = ReadlineInputMethod.new
            else
              @io = nil
            end
          when false
            @io = nil
          when true
            if defined?(ReadlineInputMethod)
              @io = ReadlineInputMethod.new
            else
              @io = nil
            end
          else
            @io = nil
          end
        end
        @io = StdioInputMethod.new unless @io

      when '-'
        @io = FileInputMethod.new($stdin)
        @irb_name = '-'
        @irb_path = '-'
      when String
        @io = FileInputMethod.new(input_method)
        @irb_name = File.basename(input_method)
        @irb_path = input_method
      else
        @io = input_method
      end
      self.save_history = IRB.conf[:SAVE_HISTORY] if IRB.conf[:SAVE_HISTORY]

      @extra_doc_dirs = IRB.conf[:EXTRA_DOC_DIRS]

      @echo = IRB.conf[:ECHO]
      if @echo.nil?
        @echo = true
      end

      @echo_on_assignment = IRB.conf[:ECHO_ON_ASSIGNMENT]
      if @echo_on_assignment.nil?
        @echo_on_assignment = :truncate
      end

      @newline_before_multiline_output = IRB.conf[:NEWLINE_BEFORE_MULTILINE_OUTPUT]
      if @newline_before_multiline_output.nil?
        @newline_before_multiline_output = true
      end

      @command_aliases = IRB.conf[:COMMAND_ALIASES]
    end

Public Instance Methods

__exit__ (ret = 0)

Alias for: exit

_set_last_value (value)

See set_last_value

Alias for: set_last_value

change_workspace (*_main)

Changes the current workspace to given object or binding.

If the optional argument is omitted, the workspace will be home_workspace which is inherited from TOPLEVEL_BINDING or the main object, IRB.conf[:MAIN_CONTEXT] when irb was initialized.

See IRB::WorkSpace.new for more information.

# File lib/irb/ext/change-ws.rb, line 32
def change_workspace(*_main)
  if _main.empty?
    @workspace = home_workspace
    return main
  end

  @workspace = WorkSpace.new(_main[0])

  if !(class<<main;ancestors;end).include?(ExtendCommandBundle)
    main.extend ExtendCommandBundle
  end
end

eval_history= (no)

Sets command result history limit. Default value is set from IRB.conf[:EVAL_HISTORY].

no is an Integer or nil.

Returns no of history items if greater than 0.

If no is 0, the number of history items is unlimited.

If no is nil, execution result history isn’t used (default).

History values are available via __ variable, see IRB::History.

# File lib/irb/ext/history.rb, line 51
def eval_history=(no)
  if no
    if defined?(@eval_history) && @eval_history
      @eval_history_values.size(no)
    else
      @eval_history_values = History.new(no)
      IRB.conf[:__TMP__EHV__] = @eval_history_values
      @workspace.evaluate(self, "__ = IRB.conf[:__TMP__EHV__]")
      IRB.conf.delete(:__TMP_EHV__)
    end
  else
    @eval_history_values = nil
  end
  @eval_history = no
end

exit (ret = 0)

Exits the current session, see IRB.irb_exit

Calls superclass method Kernel#exit

# File lib/irb/context.rb, line 511
def exit(ret = 0)
  IRB.irb_exit(@irb, ret)
rescue UncaughtThrowError
  super
end

Also aliased as: __exit__

file_input? ()

Whether io uses a File for the input_method passed when creating the current context, see ::new

# File lib/irb/context.rb, line 421
def file_input?
  @io.class == FileInputMethod
end

history_file ()

A copy of the default IRB.conf[:HISTORY_FILE]

# File lib/irb/ext/save-history.rb, line 48
def history_file
  IRB.conf[:HISTORY_FILE]
end

history_file= (hist)

Set IRB.conf[:HISTORY_FILE] to the given hist.

# File lib/irb/ext/save-history.rb, line 53
def history_file=(hist)
  IRB.conf[:HISTORY_FILE] = hist
end

home_workspace ()

Inherited from TOPLEVEL_BINDING.

# File lib/irb/ext/change-ws.rb, line 17
def home_workspace
  if defined? @home_workspace
    @home_workspace
  else
    @home_workspace = @workspace
  end
end

inspect? ()

Whether inspect_mode is set or not, see inspect_mode= for more detail.

# File lib/irb/context.rb, line 415
def inspect?
  @inspect_mode.nil? or @inspect_mode
end

inspect_mode= (opt)

Specifies the inspect mode with opt:

true: display inspect
false: display to_s
nil: inspect mode in non-math mode, non-inspect mode in math mode

See IRB::Inspector for more information.

Can also be set using the --inspect and --noinspect command line options.

See Command line options at IRB for more command line options.

# File lib/irb/context.rb, line 438
def inspect_mode=(opt)

  if i = Inspector::INSPECTORS[opt]
    @inspect_mode = opt
    @inspect_method = i
    i.init
  else
    case opt
    when nil
      if Inspector.keys_with_inspector(Inspector::INSPECTORS[true]).include?(@inspect_mode)
        self.inspect_mode = false
      elsif Inspector.keys_with_inspector(Inspector::INSPECTORS[false]).include?(@inspect_mode)
        self.inspect_mode = true
      else
        puts "Can't switch inspect mode."
        return
      end
    when /^\s*\{.*\}\s*$/
      begin
        inspector = eval "proc#{opt}"
      rescue Exception
        puts "Can't switch inspect mode(#{opt})."
        return
      end
      self.inspect_mode = inspector
    when Proc
      self.inspect_mode = IRB::Inspector(opt)
    when Inspector
      prefix = "usr%d"
      i = 1
      while Inspector::INSPECTORS[format(prefix, i)]; i += 1; end
      @inspect_mode = format(prefix, i)
      @inspect_method = opt
      Inspector.def_inspector(format(prefix, i), @inspect_method)
    else
      puts "Can't switch inspect mode(#{opt})."
      return
    end
  end
  print "Switch to#{unless @inspect_mode; ' non';end} inspect mode.\n" if verbose?
  @inspect_mode
end

irb_level ()

Size of the current WorkSpace stack

# File lib/irb/ext/workspaces.rb, line 17
def irb_level
  workspace_stack.size
end

main ()

The top-level workspace, see WorkSpace#main

# File lib/irb/context.rb, line 160
def main
  @workspace.main
end

pop_workspace ()

Removes the last element from the current workspaces stack and returns it, or nil if the current workspace stack is empty.

Also, see push_workspace.

# File lib/irb/ext/workspaces.rb, line 58
def pop_workspace
  if workspaces.empty?
    print "workspace stack empty\n"
    return
  end
  @workspace = workspaces.pop
end

prompt_mode= (mode)

Sets the mode of the prompt in this context.

See Customizing the IRB Prompt at IRB for more information.

# File lib/irb/context.rb, line 398
def prompt_mode=(mode)
  @prompt_mode = mode
  pconf = IRB.conf[:PROMPT][mode]
  @prompt_i = pconf[:PROMPT_I]
  @prompt_s = pconf[:PROMPT_S]
  @prompt_c = pconf[:PROMPT_C]
  @prompt_n = pconf[:PROMPT_N]
  @return_format = pconf[:RETURN]
  @return_format = "%s\n" if @return_format == nil
  if ai = pconf.include?(:AUTO_INDENT)
    @auto_indent_mode = ai
  else
    @auto_indent_mode = IRB.conf[:AUTO_INDENT]
  end
end

prompting? ()

Whether verbose? is true, and input_method is either StdioInputMethod or RelineInputMethod or ReadlineInputMethod, see io for more information.

# File lib/irb/context.rb, line 379
def prompting?
  verbose? || (STDIN.tty? && @io.kind_of?(StdioInputMethod) ||
               @io.kind_of?(RelineInputMethod) ||
               (defined?(ReadlineInputMethod) && @io.kind_of?(ReadlineInputMethod)))
end

push_workspace (*_main)

Creates a new workspace with the given object or binding, and appends it onto the current workspaces stack.

See IRB::Context#change_workspace and IRB::WorkSpace.new for more information.

# File lib/irb/ext/workspaces.rb, line 35
def push_workspace(*_main)
  if _main.empty?
    if workspaces.empty?
      print "No other workspace\n"
      return nil
    end
    ws = workspaces.pop
    workspaces.push @workspace
    @workspace = ws
    return workspaces
  end

  workspaces.push @workspace
  @workspace = WorkSpace.new(@workspace.binding, _main[0])
  if !(class<<main;ancestors;end).include?(ExtendCommandBundle)
    main.extend ExtendCommandBundle
  end
end

save_history ()

A copy of the default IRB.conf[:SAVE_HISTORY]

# File lib/irb/ext/save-history.rb, line 24
def save_history
  IRB.conf[:SAVE_HISTORY]
end

save_history= (val)

Sets IRB.conf[:SAVE_HISTORY] to the given val and calls init_save_history with this context.

Will store the number of val entries of history in the history_file

Add the following to your .irbrc to change the number of history entries stored to 1000:

IRB.conf[:SAVE_HISTORY] = 1000

# File lib/irb/ext/save-history.rb, line 38
def save_history=(val)
  IRB.conf[:SAVE_HISTORY] = val
  if val
    main_context = IRB.conf[:MAIN_CONTEXT]
    main_context = self unless main_context
    main_context.init_save_history
  end
end

set_last_value (value)

Sets the return value from the last statement evaluated in this context to last_value.

# File lib/irb/context.rb, line 390
def set_last_value(value)
  @last_value = value
  @workspace.local_variable_set :_, value
end

Also aliased as: _set_last_value

symbol_alias? (command)

Return true if it’s aliased from the argument and it’s not an identifier.

# File lib/irb/context.rb, line 549
def symbol_alias?(command)
  return nil if command.match?(/\A\w+\z/)
  command_aliases.key?(command.to_sym)
end

transform_args? (command)

Return true if the command supports transforming args

# File lib/irb/context.rb, line 555
def transform_args?(command)
  command = command_aliases.fetch(command.to_sym, command)
  ExtendCommandBundle.load_command(command)&.respond_to?(:transform_args)
end

use_loader ()

Returns whether irb‘s own file reader method is used by load/require or not.

This mode is globally affected (irb-wide).

# File lib/irb/ext/use-loader.rb, line 43
def use_loader
  IRB.conf[:USE_LOADER]
end

Also aliased as: use_loader?

use_loader= (opt)

Sets IRB.conf[:USE_LOADER]

See use_loader for more information.

# File lib/irb/ext/use-loader.rb, line 53
def use_loader=(opt)

  if IRB.conf[:USE_LOADER] != opt
    IRB.conf[:USE_LOADER] = opt
    if opt
      if !$".include?("irb/cmd/load")
      end
      (class<<@workspace.main;self;end).instance_eval {
        alias_method :load, :irb_load
        alias_method :require, :irb_require
      }
    else
      (class<<@workspace.main;self;end).instance_eval {
        alias_method :load, :__original__load__IRB_use_loader__
        alias_method :require, :__original__require__IRB_use_loader__
      }
    end
  end
  print "Switch to load/require#{unless use_loader; ' non';end} trace mode.\n" if verbose?
  opt
end

use_loader? ()

Alias for: use_loader

use_tracer= (opt)

# File lib/irb/ext/tracer.rb, line 19
def use_tracer=(opt)
  # do nothing
end

verbose? ()

Returns whether messages are displayed or not.

# File lib/irb/context.rb, line 360
def verbose?
  if @verbose.nil?
    if @io.kind_of?(RelineInputMethod)
      false
    elsif defined?(ReadlineInputMethod) && @io.kind_of?(ReadlineInputMethod)
      false
    elsif !STDIN.tty? or @io.kind_of?(FileInputMethod)
      true
    else
      false
    end
  else
    @verbose
  end
end

workspaces ()

WorkSpaces in the current stack

# File lib/irb/ext/workspaces.rb, line 22
def workspaces
  if defined? @workspaces
    @workspaces
  else
    @workspaces = []
  end
end