Results for: "partition"

If a class variable is written within a method definition, it has a different type than everywhere else.

Foo
^^^

"foo #@bar"
     ^^^^^

foo => [*, bar, *]
       ^^^^^^^^^^^

super
^^^^^

super {}
^^^^^^^^

foo => {}
       ^^

foo { |bar,| }
          ^

foo[bar], = 1
^^^^^^^^

/(?<foo>foo)/ =~ bar
^^^^^^^^^^^^^^^^^^^^

foo = 1 and bar => ^foo
                   ^^^^

class << self; end
^^^^^^^^^^^^^^^^^^

Example:

x.foo += 42
         ^^

Example:

x[1] += 42
  ^^^^^^^^

Same as Enumerator#with_index(0), i.e. there is no starting offset.

If no block is given, a new Enumerator is returned that includes the index.

Iterates the given block for each element with an arbitrary object, obj, and returns obj

If no block is given, returns a new Enumerator.

Example

to_three = Enumerator.new do |y|
  3.times do |x|
    y << x
  end
end

to_three_with_string = to_three.with_object("foo")
to_three_with_string.each do |x,string|
  puts "#{string}: #{x}"
end

# => foo: 0
# => foo: 1
# => foo: 2

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

Sets the instance variable named by symbol to the given object. This may circumvent the encapsulation intended by the author of the class, so it should be used with care. The variable does not have to exist prior to this call. If the instance variable name is passed as a string, that string is converted to a symbol.

class Fred
  def initialize(p1, p2)
    @a, @b = p1, p2
  end
end
fred = Fred.new('cat', 99)
fred.instance_variable_set(:@a, 'dog')   #=> "dog"
fred.instance_variable_set(:@c, 'cat')   #=> "cat"
fred.inspect                             #=> "#<Fred:0x401b3da8 @a=\"dog\", @b=99, @c=\"cat\">"

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. The name can be passed as a symbol or as a string.

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 public 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. If a block or a method has parameters, they’re used as method parameters.

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!"

chris = "Chris"
chris.define_singleton_method(:greet) {|greeting| "#{greeting}, I'm Chris!" }
chris.greet("Hi") #=> "Hi, I'm Chris!"

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.

Sets the temporary name of the module. This name is reflected in introspection of the module and the values that are related to it, such as instances, constants, and methods.

The name should be nil or a non-empty string that is not a valid constant path (to avoid confusing between permanent and temporary names).

The method can be useful to distinguish dynamically generated classes and modules without assigning them to constants.

If the module is given a permanent name by assigning it to a constant, the temporary name is discarded. A temporary name can’t be assigned to modules that have a permanent name.

If the given name is nil, the module becomes anonymous again.

Example:

m = Module.new # => #<Module:0x0000000102c68f38>
m.name #=> nil

m.set_temporary_name("fake_name") # => fake_name
m.name #=> "fake_name"

m.set_temporary_name(nil) # => #<Module:0x0000000102c68f38>
m.name #=> nil

c = Class.new
c.set_temporary_name("MyClass(with description)")

c.new # => #<MyClass(with description):0x0....>

c::M = m
c::M.name #=> "MyClass(with description)::M"

# Assigning to a constant replaces the name with a permanent one
C = c

C.name #=> "C"
C::M.name #=> "C::M"
c.new # => #<C:0x0....>

Removes the named class variable from the receiver, returning that variable’s value.

class Example
  @@var = 99
  puts 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