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 enable auto-indentation in irb:

IRB.conf[:AUTO_INDENT] = true

irb_context.auto_indent_mode = true

IRB.CurrentContext.auto_indent_mode = true

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.

debug_level[R]

The debug level of irb

See debug_level= for more information.

echo[RW]

Whether to echo the return value to output or not.

Uses IRB.conf 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 if available, or defaults to true.

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

eval_history[R]

The command result history limit.

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, 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]

math?[R]

Returns whether bc mode is enabled.

See math_mode=

math_mode[R]

Returns whether bc mode is enabled.

See math_mode=

prompt_c[RW]

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

See IRB for more information.

prompt_i[RW]

Standard IRB prompt

See 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 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_readline[R]

Whether Readline is enabled or not.

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

See use_readline= for more information.

use_readline?[R]

Whether Readline is enabled or not.

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

See use_readline= for more information.

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, output_method = nil) click to toggle source

Creates a new IRB context.

The optional input_method argument:

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

# File lib/irb/context.rb, line 26
def initialize(irb, workspace = nil, input_method = nil, output_method = nil)
  @irb = irb
  if workspace
    @workspace = workspace
  else
    @workspace = WorkSpace.new
  end
  @thread = Thread.current if defined? Thread

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

  @use_readline = IRB.conf[:USE_READLINE]
  @verbose = IRB.conf[:VERBOSE]
  @io = nil

  self.inspect_mode = IRB.conf[:INSPECT_MODE]
  self.math_mode = IRB.conf[:MATH_MODE] if IRB.conf[:MATH_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
    case use_readline?
    when nil
      if (defined?(ReadlineInputMethod) && STDIN.tty? &&
          IRB.conf[:PROMPT_MODE] != :INF_RUBY)
        @io = ReadlineInputMethod.new
      else
        @io = StdioInputMethod.new
      end
    when false
      @io = StdioInputMethod.new
    when true
      if defined?(ReadlineInputMethod)
        @io = ReadlineInputMethod.new
      else
        @io = StdioInputMethod.new
      end
    end

  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]

  if output_method
    @output_method = output_method
  else
    @output_method = StdioOutputMethod.new
  end

  @echo = IRB.conf[:ECHO]
  if @echo.nil?
    @echo = true
  end
  self.debug_level = IRB.conf[:DEBUG_LEVEL]
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) 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 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

debug?() click to toggle source

Whether or not debug mode is enabled, see debug_level=.

# File lib/irb/context.rb, line 374
def debug?
  @debug_level > 0
end

debug_level=(value) click to toggle source

Sets the debug level of irb

Can also be set using the --irb_debug command line option.

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

# File lib/irb/context.rb, line 368
def debug_level=(value)
  @debug_level = value
  RubyLex.debug_level = value
end

eval_history=(no) click to toggle source

Sets command result history limit.

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).

# File lib/irb/ext/history.rb, line 44
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

# File lib/irb/context.rb, line 389
def exit(ret = 0)
  IRB.irb_exit(@irb, ret)
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 lib/irb/context.rb, line 292
def file_input?
  @io.class == FileInputMethod
end

history_file() click to toggle source

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

# File lib/irb/ext/save-history.rb, line 50
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 lib/irb/ext/save-history.rb, line 55
def history_file=(hist)
  IRB.conf[:HISTORY_FILE] = hist
end

home_workspace() click to toggle source

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?() click to toggle source

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

# File lib/irb/context.rb, line 286
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 lib/irb/context.rb, line 309
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 lib/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 lib/irb/context.rb, line 107
def main
  @workspace.main
end

math_mode=(opt) click to toggle source

Sets bc mode, which loads lib/mathn.rb so fractions or matrix are available.

Also available as the -m command line option.

See Command line options at IRB and the unix manpage bc(1) for more information.

# File lib/irb/ext/math-mode.rb, line 30
def math_mode=(opt)
  if @math_mode == true && !opt
    IRB.fail CantReturnToNormalMode
    return
  end

  @math_mode = opt
  if math_mode
    main.extend Math
    print "start math mode\n" if verbose?
  end
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 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) click to toggle source

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 270
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]
  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 ReadlineInputMethod, see io for more information.

# File lib/irb/context.rb, line 252
def prompting?
  verbose? || (STDIN.tty? && @io.kind_of?(StdioInputMethod) ||
               (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 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() click to toggle source

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

# File lib/irb/ext/save-history.rb, line 26
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 lib/irb/ext/save-history.rb, line 40
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 lib/irb/context.rb, line 262
def set_last_value(value)
  @last_value = value
  @workspace.evaluate self, "_ = IRB.CurrentContext.last_value"
end

Also aliased as: _set_last_value

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 lib/irb/ext/use-loader.rb, line 41
def use_loader
  IRB.conf[:USE_LOADER]
end

Also aliased as: use_loader?

use_loader=(opt) click to toggle source

Sets IRB.conf

See use_loader for more information.

# File lib/irb/ext/use-loader.rb, line 50
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_readline=(opt) click to toggle source

Obsolete method.

Can be set using the --noreadline and --readline command line options.

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

# File lib/irb/context.rb, line 358
def use_readline=(opt)
  print "This method is obsolete."
  print "Do nothing."
end

use_tracer=(opt) click to toggle source

Sets whether or not to use the Tracer library when evaluating statements in this context.

See lib/tracer.rb for more information.

# File lib/irb/ext/tracer.rb, line 37
def use_tracer=(opt)
  if opt
    Tracer.set_get_line_procs(@irb_path) {
      |line_no, *rests|
      @io.line(line_no)
    }
  elsif !opt && @use_tracer
    Tracer.off
  end
  @use_tracer=opt
end

verbose?() click to toggle source

Returns whether messages are displayed or not.

# File lib/irb/context.rb, line 236
def verbose?
  if @verbose.nil?
    if 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 lib/irb/ext/workspaces.rb, line 22
def workspaces
  if defined? @workspaces
    @workspaces
  else
    @workspaces = []
  end
end