class IRB::Context

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

Attributes

ap_name[RW]

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

auto_indent_mode[RW]

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

or

irb_context.auto_indent_mode = false

or

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

or

irb_context.echo_on_assignment = :truncate or true or false

or

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

or

irb_context.echo_on_assignment = :truncate or true or false

or

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) click to toggle source

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 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
        @use_multiline = IRB.conf[:USE_RELINE]
      elsif IRB.conf.has_key?(:USE_REIDLINE)
        warn <<~MSG.strip
          USE_REIDLINE is deprecated, please use USE_RELINE 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)
Alias for: set_last_value
change_workspace(*_main) click to toggle source

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 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) click to toggle source

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 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) click to toggle source

Exits the current session, see IRB.irb_exit

Calls superclass method
# File irb/context.rb, line 508
def exit(ret = 0)
  IRB.irb_exit(@irb, ret)
rescue UncaughtThrowError
  super
end
Also aliased as: __exit__
file_input?() click to toggle source

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

# File irb/context.rb, line 418
def file_input?
  @io.class == FileInputMethod
end
history_file() click to toggle source

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

# File irb/ext/save-history.rb, line 48
def history_file
  IRB.conf[:HISTORY_FILE]
end
history_file=(hist) click to toggle source

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

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

Inherited from TOPLEVEL_BINDING.

# File irb/ext/change-ws.rb, line 17
def home_workspace
  if defined? @home_workspace
    @home_workspace
  else
    @home_workspace = @workspace
  end
end
inspect?() click to toggle source

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

# File irb/context.rb, line 412
def inspect?
  @inspect_mode.nil? or @inspect_mode
end
inspect_mode=(opt) click to toggle source

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 irb/context.rb, line 435
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() click to toggle source

Size of the current WorkSpace stack

# File irb/ext/workspaces.rb, line 17
def irb_level
  workspace_stack.size
end
main() click to toggle source

The top-level workspace, see WorkSpace#main

# File irb/context.rb, line 157
def main
  @workspace.main
end
pop_workspace() click to toggle source

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 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) click to toggle source

Sets the mode of the prompt in this context.

See Customizing the IRB Prompt at IRB for more information.

# File irb/context.rb, line 395
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?() click to toggle source

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

# File irb/context.rb, line 376
def prompting?
  verbose? || (STDIN.tty? && @io.kind_of?(StdioInputMethod) ||
               @io.kind_of?(RelineInputMethod) ||
               (defined?(ReadlineInputMethod) && @io.kind_of?(ReadlineInputMethod)))
end
push_workspace(*_main) click to toggle source

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 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() click to toggle source

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

# File irb/ext/save-history.rb, line 24
def save_history
  IRB.conf[:SAVE_HISTORY]
end
save_history=(val) click to toggle source

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 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) click to toggle source

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

# File irb/context.rb, line 387
def set_last_value(value)
  @last_value = value
  @workspace.local_variable_set :_, value
end
Also aliased as: _set_last_value
symbol_alias(command) click to toggle source

Return a command name if it’s aliased from the argument and it’s not an identifier.

# File irb/context.rb, line 546
def symbol_alias(command)
  return nil if command.match?(/\A\w+\z/)
  command_aliases[command.to_sym]
end
use_loader() click to toggle source

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

This mode is globally affected (irb-wide).

# File irb/ext/use-loader.rb, line 43
def use_loader
  IRB.conf[:USE_LOADER]
end
Also aliased as: use_loader?
use_loader=(opt) click to toggle source

Sets IRB.conf[:USE_LOADER]

See use_loader for more information.

# File 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) click to toggle source
# File irb/ext/tracer.rb, line 19
def use_tracer=(opt)
  # do nothing
end
verbose?() click to toggle source

Returns whether messages are displayed or not.

# File irb/context.rb, line 357
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() click to toggle source

WorkSpaces in the current stack

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