Returns an empty resolution state @return [ResolutionState] an empty state
Trap attempts to add methods to Numeric
objects. Always raises a TypeError
.
Numerics should be values; singleton_methods should not be added to them.
Returns the value of the given instance variable, or nil if the instance variable is not set. The @
part of the variable name should be included for regular instance variables. Throws a NameError
exception if the supplied symbol is not valid as an instance variable name. String arguments are converted to symbols.
class Fred def initialize(p1, p2) @a, @b = p1, p2 end end fred = Fred.new('cat', 99) fred.instance_variable_get(:@a) #=> "cat" fred.instance_variable_get("@b") #=> 99
Returns true
if the given instance variable is defined in obj. String arguments are converted to symbols.
class Fred def initialize(p1, p2) @a, @b = p1, p2 end end fred = Fred.new('cat', 99) fred.instance_variable_defined?(:@a) #=> true fred.instance_variable_defined?("@b") #=> true fred.instance_variable_defined?("@c") #=> false
Removes the named instance variable from obj, returning that variable’s value.
class Dummy attr_reader :var def initialize @var = 99 end def remove remove_instance_variable(:@var) end end d = Dummy.new d.var #=> 99 d.remove #=> 99 d.var #=> nil
Defines a singleton method in the receiver. The method parameter can be a Proc
, a Method
or an UnboundMethod
object. If a block is specified, it is used as the method body.
class A class << self def class_name to_s end end end A.define_singleton_method(:who_am_i) do "I am: #{class_name}" end A.who_am_i # ==> "I am: A" guy = "Bob" guy.define_singleton_method(:hello) { "#{self}: Hello there!" } guy.hello #=> "Bob: Hello there!"
DO NOT USE THIS DIRECTLY.
Hook method to return whether the obj can respond to id method or not.
When the method name parameter is given as a string, the string is converted to a symbol.
See respond_to?
, and the example of BasicObject
.
Removes the definition of the sym, returning that constant’s value.
class Dummy @@var = 99 puts @@var remove_class_variable(:@@var) p(defined? @@var) end
produces:
99 nil
Returns the value of the given class variable (or throws a NameError
exception). The @@
part of the variable name should be included for regular class variables. String arguments are converted to symbols.
class Fred @@foo = 99 end Fred.class_variable_get(:@@foo) #=> 99
Returns true
if the given class variable is defined in obj. String arguments are converted to symbols.
class Fred @@foo = 99 end Fred.class_variable_defined?(:@@foo) #=> true Fred.class_variable_defined?(:@@bar) #=> false
Packs port and host as an AF_INET/AF_INET6 sockaddr string.
Socket.sockaddr_in(80, "127.0.0.1") #=> "\x02\x00\x00P\x7F\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00" Socket.sockaddr_in(80, "::1") #=> "\n\x00\x00P\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00"
Packs path as an AF_UNIX sockaddr string.
Socket.sockaddr_un("/tmp/sock") #=> "\x01\x00/tmp/sock\x00\x00..."
Returns reference counter of Dispatch interface of WIN32OLE
object. You should not use this method because this method exists only for debugging WIN32OLE
.
Returns true when OLE object has OLE method, otherwise returns false.
ie = WIN32OLE.new('InternetExplorer.Application') ie.ole_respond_to?("gohome") => true
Invoked as a callback whenever a singleton method is added to the receiver.
module Chatty def Chatty.singleton_method_added(id) puts "Adding #{id.id2name}" end def self.one() end def two() end def Chatty.three() end end
produces:
Adding singleton_method_added Adding one Adding three
Invoked as a callback whenever a singleton method is removed from the receiver.
module Chatty def Chatty.singleton_method_removed(id) puts "Removing #{id.id2name}" end def self.one() end def two() end def Chatty.three() end class << self remove_method :three remove_method :one end end
produces:
Removing three Removing one
Invoked as a callback whenever a singleton method is undefined in the receiver.
module Chatty def Chatty.singleton_method_undefined(id) puts "Undefining #{id.id2name}" end def Chatty.one() end class << self undef_method(:one) end end
produces:
Undefining one
Checks for a method provided by this the delegate object by forwarding the call through _getobj_.
Returns the directories in the current shell’s PATH environment variable as an array of directory names. This sets the system_path
for all instances of Shell
.
Example: If in your current shell, you did:
$ echo $PATH /usr/bin:/bin:/usr/local/bin
Running this method in the above shell would then return:
["/usr/bin", "/bin", "/usr/local/bin"]
Sets the system_path
that new instances of Shell
should have as their initial system_path.
path
should be an array of directory name strings.