mruby-class-ext

This mrbgem extends the Module and Class classes in mruby, providing additional methods for reflection and class manipulation.

Module Methods

mod < other

Returns true if mod is a subclass/submodule of other. Returns false if mod is the same as other. Returns nil if there's no relationship between the two. (Think of the relationship in terms of the class definition: "class A < B" implies "A < B".)

mod <= other

Returns true if mod is a subclass/submodule of other or is the same as other. Returns nil if there's no relationship between the two. (Think of the relationship in terms of the class definition: "class A < B" implies "A <= B".)

mod > other

Returns true if mod is an ancestor of other. Returns false if mod is the same as other. Returns nil if there's no relationship between the two. (Think of the relationship in terms of the class definition: "class A < B" implies "B > A".)

mod >= other

Returns true if mod is an ancestor of other, or the two modules are the same. Returns nil if there's no relationship between the two. (Think of the relationship in terms of the class definition: "class A < B" implies "B >= A".)

module <=> other_module

Comparison---Returns -1, 0, +1 or nil depending on whether module includes other_module, they are the same, or if module is included by other_module.

Returns nil if module has no relationship with other_module, if other_module is not a module, or if the two values are incomparable.

name

Returns the name of the module.

singleton_class?

Returns true if the module is a singleton class.

module_exec(arg...) {|var...| block } -> obj

class_exec(arg...) {|var...| block } -> obj

Evaluates the given block in the context of the class/module. The method defined in the block will belong to the receiver. Any arguments passed to the method will be passed to the block. This can be used if the block needs to access instance variables.

class Thing
end
Thing.class_exec{
  def hello() "Hello there!" end
}
puts Thing.new.hello()

Class Methods

subclasses -> array

Returns an array of classes where the receiver is the direct superclass of the class, excluding singleton classes. The order of the returned array is not defined.

class A; end
class B < A; end
class C < B; end
class D < A; end

A.subclasses        #=> [D, B]
B.subclasses        #=> [C]
C.subclasses        #=> []

attached_object -> object

Returns the object for which the receiver is the singleton class. Raises a TypeError if the class is not a singleton class.

class Foo; end

Foo.singleton_class.attached_object        #=> Foo
Foo.attached_object                        #=> TypeError: not a singleton class
Foo.new.singleton_class.attached_object    #=> #<Foo:0x000000010491a370>
TrueClass.attached_object                  #=> TypeError: not a singleton class
NilClass.attached_object                   #=> TypeError: not a singleton class