Gecko [ gandhischool.edu.np ]

Name	Size	Permission
benchmark	[ DIR ]	drwxr-xr-x
bigdecimal	[ DIR ]	drwxr-xr-x
bundler	[ DIR ]	drwxr-xr-x
cgi	[ DIR ]	drwxr-xr-x
csv	[ DIR ]	drwxr-xr-x
did_you_mean	[ DIR ]	drwxr-xr-x
digest	[ DIR ]	drwxr-xr-x
drb	[ DIR ]	drwxr-xr-x
fiddle	[ DIR ]	drwxr-xr-x
forwardable	[ DIR ]	drwxr-xr-x
io	[ DIR ]	drwxr-xr-x
irb	[ DIR ]	drwxr-xr-x
json	[ DIR ]	drwxr-xr-x
logger	[ DIR ]	drwxr-xr-x
matrix	[ DIR ]	drwxr-xr-x
net	[ DIR ]	drwxr-xr-x
openssl	[ DIR ]	drwxr-xr-x
optparse	[ DIR ]	drwxr-xr-x
psych	[ DIR ]	drwxr-xr-x
racc	[ DIR ]	drwxr-xr-x
rdoc	[ DIR ]	drwxr-xr-x
reline	[ DIR ]	drwxr-xr-x
rinda	[ DIR ]	drwxr-xr-x
ripper	[ DIR ]	drwxr-xr-x
rubygems	[ DIR ]	drwxr-xr-x
set	[ DIR ]	drwxr-xr-x
syslog	[ DIR ]	drwxr-xr-x
unicode_normalize	[ DIR ]	drwxr-xr-x
uri	[ DIR ]	drwxr-xr-x
yaml	[ DIR ]	drwxr-xr-x
English.rb	6.11 KB	-rw-r--r--
abbrev.rb	3.45 KB	-rw-r--r--
base64.rb	3.3 KB	-rw-r--r--
benchmark.rb	18.02 KB	-rw-r--r--
bigdecimal.rb	24 B	-rw-r--r--
bundler.rb	23.79 KB	-rw-r--r--
cgi.rb	9.82 KB	-rw-r--r--
coverage.rb	368 B	-rw-r--r--
csv.rb	86.71 KB	-rw-r--r--
date.rb	1012 B	-rw-r--r--
debug.rb	29.91 KB	-rw-r--r--
delegate.rb	11.68 KB	-rw-r--r--
did_you_mean.rb	3.85 KB	-rw-r--r--
digest.rb	2.83 KB	-rw-r--r--
drb.rb	50 B	-rw-r--r--
erb.rb	28.81 KB	-rw-r--r--
expect.rb	2.17 KB	-rw-r--r--
fiddle.rb	1.71 KB	-rw-r--r--
fileutils.rb	48.26 KB	-rw-r--r--
find.rb	2.47 KB	-rw-r--r--
forwardable.rb	8.98 KB	-rw-r--r--
getoptlong.rb	15.45 KB	-rw-r--r--
ipaddr.rb	19.52 KB	-rw-r--r--
irb.rb	29.13 KB	-rw-r--r--
json.rb	19.3 KB	-rw-r--r--
kconv.rb	5.72 KB	-rw-r--r--
logger.rb	16.48 KB	-rw-r--r--
matrix.rb	61.83 KB	-rw-r--r--
mkmf.rb	86.35 KB	-rw-r--r--
monitor.rb	6.76 KB	-rw-r--r--
mutex_m.rb	2.23 KB	-rw-r--r--
objspace.rb	2.66 KB	-rw-r--r--
observer.rb	6.38 KB	-rw-r--r--
open-uri.rb	24.74 KB	-rw-r--r--
open3.rb	21.93 KB	-rw-r--r--
openssl.rb	1.03 KB	-rw-r--r--
optionparser.rb	59 B	-rw-r--r--
optparse.rb	59.53 KB	-rw-r--r--
ostruct.rb	12.38 KB	-rw-r--r--
pathname.rb	16.46 KB	-rw-r--r--
pp.rb	15.81 KB	-rw-r--r--
prettyprint.rb	15.9 KB	-rw-r--r--
prime.rb	15.13 KB	-rw-r--r--
pstore.rb	14.73 KB	-rw-r--r--
psych.rb	22.28 KB	-rw-r--r--
racc.rb	137 B	-rw-r--r--
rdoc.rb	5.38 KB	-rw-r--r--
readline.rb	113 B	-rw-r--r--
reline.rb	13.9 KB	-rw-r--r--
resolv-replace.rb	1.76 KB	-rw-r--r--
resolv.rb	74.35 KB	-rw-r--r--
ripper.rb	2.44 KB	-rw-r--r--
rubygems.rb	36.58 KB	-rw-r--r--
securerandom.rb	8.86 KB	-rw-r--r--
set.rb	19.42 KB	-rw-r--r--
shellwords.rb	7.09 KB	-rw-r--r--
singleton.rb	4.08 KB	-rw-r--r--
socket.rb	43.65 KB	-rw-r--r--
tempfile.rb	12.43 KB	-rw-r--r--
time.rb	24.27 KB	-rw-r--r--
timeout.rb	4 KB	-rw-r--r--
tmpdir.rb	4.4 KB	-rw-r--r--
tracer.rb	6.5 KB	-rw-r--r--
tsort.rb	14.3 KB	-rw-r--r--
un.rb	10.11 KB	-rw-r--r--
uri.rb	3.04 KB	-rw-r--r--
weakref.rb	1.46 KB	-rw-r--r--
yaml.rb	1.8 KB	-rw-r--r--

Code Editor : singleton.rb

# frozen_string_literal: false

# The Singleton module implements the Singleton pattern.
#
# == Usage
#
# To use Singleton, include the module in your class.
#
#    class Klass
#       include Singleton
#       # ...
#    end
#
# This ensures that only one instance of Klass can be created.
#
#      a,b = Klass.instance, Klass.instance
#
#      a == b
#      # => true
#
#      Klass.new
#      # => NoMethodError - new is private ...
#
# The instance is created at upon the first call of Klass.instance().
#
#      class OtherKlass
#        include Singleton
#        # ...
#      end
#
#      ObjectSpace.each_object(OtherKlass){}
#      # => 0
#
#      OtherKlass.instance
#      ObjectSpace.each_object(OtherKlass){}
#      # => 1
#
#
# This behavior is preserved under inheritance and cloning.
#
# == Implementation
#
# This above is achieved by:
#
# *  Making Klass.new and Klass.allocate private.
#
# *  Overriding Klass.inherited(sub_klass) and Klass.clone() to ensure that the
#    Singleton properties are kept when inherited and cloned.
#
# *  Providing the Klass.instance() method that returns the same object each
#    time it is called.
#
# *  Overriding Klass._load(str) to call Klass.instance().
#
# *  Overriding Klass#clone and Klass#dup to raise TypeErrors to prevent
#    cloning or duping.
#
# == Singleton and Marshal
#
# By default Singleton's #_dump(depth) returns the empty string. Marshalling by
# default will strip state information, e.g. instance variables from the instance.
# Classes using Singleton can provide custom _load(str) and _dump(depth) methods
# to retain some of the previous state of the instance.
#
#    require 'singleton'
#
#    class Example
#      include Singleton
#      attr_accessor :keep, :strip
#      def _dump(depth)
#        # this strips the @strip information from the instance
#        Marshal.dump(@keep, depth)
#      end
#
#      def self._load(str)
#        instance.keep = Marshal.load(str)
#        instance
#      end
#    end
#
#    a = Example.instance
#    a.keep = "keep this"
#    a.strip = "get rid of this"
#
#    stored_state = Marshal.dump(a)
#
#    a.keep = nil
#    a.strip = nil
#    b = Marshal.load(stored_state)
#    p a == b  #  => true
#    p a.keep  #  => "keep this"
#    p a.strip #  => nil
#
module Singleton
  VERSION = "0.1.1"

# Raises a TypeError to prevent cloning.
  def clone
    raise TypeError, "can't clone instance of singleton #{self.class}"
  end

# Raises a TypeError to prevent duping.
  def dup
    raise TypeError, "can't dup instance of singleton #{self.class}"
  end

# By default, do not retain any state when marshalling.
  def _dump(depth = -1)
    ''
  end

module SingletonClassMethods # :nodoc:

def clone # :nodoc:
      Singleton.__init__(super)
    end

# By default calls instance(). Override to retain singleton state.
    def _load(str)
      instance
    end

def instance # :nodoc:
      return @singleton__instance__ if @singleton__instance__
      @singleton__mutex__.synchronize {
        return @singleton__instance__ if @singleton__instance__
        @singleton__instance__ = new()
      }
      @singleton__instance__
    end

private

def inherited(sub_klass)
      super
      Singleton.__init__(sub_klass)
    end
  end

class << Singleton # :nodoc:
    def __init__(klass) # :nodoc:
      klass.instance_eval {
        @singleton__instance__ = nil
        @singleton__mutex__ = Thread::Mutex.new
      }
      klass
    end

private

# extending an object with Singleton is a bad idea
    undef_method :extend_object

def append_features(mod)
      #  help out people counting on transitive mixins
      unless mod.instance_of?(Class)
        raise TypeError, "Inclusion of the OO-Singleton module in module #{mod}"
      end
      super
    end

def included(klass)
      super
      klass.private_class_method :new, :allocate
      klass.extend SingletonClassMethods
      Singleton.__init__(klass)
    end
  end

##
  # :singleton-method: _load
  #  By default calls instance(). Override to retain singleton state.

##
  # :singleton-method: instance
  #  Returns the singleton instance.
end

${this.title}

Code Editor : singleton.rb