class IRB::Inspector

An irb inspector

In order to create your own custom inspector there are two things you should be aware of:

Inspector uses inspect_value, or inspect_proc, for output of return values.

This also allows for an optional init+, or init_proc, which is called when the inspector is activated.

Knowing this, you can create a rudimentary inspector as follows:

irb(main):001:0> ins = IRB::Inspector.new(proc{ |v| "omg! #{v}" })
irb(main):001:0> IRB.CurrentContext.inspect_mode = ins # => omg! #<IRB::Inspector:0x007f46f7ba7d28>
irb(main):001:0> "what?" #=> omg! what?

Constants

INSPECTORS

Default inspectors available to irb, this includes:

:pp: Using Kernel#pretty_inspect
:yaml: Using YAML.dump
:marshal: Using Marshal.dump

KERNEL_INSPECT

Public Class Methods

def_inspector (key, arg=nil, &block)

Source

# File lib/irb/inspector.rb, line 58
def def_inspector(key, arg=nil, &block)
  if block_given?
    inspector = IRB::Inspector(block, arg)
  else
    inspector = arg
  end

  case key
  when Array
    for k in key
      def_inspector(k, inspector)
    end
  when Symbol
    INSPECTORS[key] = inspector
    INSPECTORS[key.to_s] = inspector
  when String
    INSPECTORS[key] = inspector
    INSPECTORS[key.intern] = inspector
  else
    INSPECTORS[key] = inspector
  end
end

Example

Inspector.def_inspector(key, init_p=nil){|v| v.inspect}
Inspector.def_inspector([key1,..], init_p=nil){|v| v.inspect}
Inspector.def_inspector(key, inspector)
Inspector.def_inspector([key1,...], inspector)

keys_with_inspector (inspector)

Source

# File lib/irb/inspector.rb, line 48
def keys_with_inspector(inspector)
  INSPECTORS.select{|k, v| v == inspector}.collect{|k, v| k}
end

Determines the inspector to use where inspector is one of the keys passed during inspector definition.

new (inspect_proc, init_proc = nil)

Source

# File lib/irb/inspector.rb, line 84
def initialize(inspect_proc, init_proc = nil)
  @init = init_proc
  @inspect = inspect_proc
end

Creates a new inspector object, using the given inspect_proc when output return values in irb.

Public Instance Methods

init ()

Source

# File lib/irb/inspector.rb, line 91
def init
  @init.call if @init
end

Proc to call when the inspector is activated, good for requiring dependent libraries.

inspect_value (v)

Source

# File lib/irb/inspector.rb, line 96
def inspect_value(v)
  @inspect.call(v)
rescue => e
  puts "An error occurred when inspecting the object: #{e.inspect}"

  begin
    puts "Result of Kernel#inspect: #{KERNEL_INSPECT.bind_call(v)}"
    ''
  rescue => e
    puts "An error occurred when running Kernel#inspect: #{e.inspect}"
    puts e.backtrace.join("\n")
    ''
  end
end

Proc to call when the input is evaluated and output in irb.