Class: Module
| Relationships & Source Files | |
| Extension / Inclusion / Inheritance Descendants | |
| Subclasses: | |
| Inherits: | Object | 
| Defined in: | class.c, eval.c, load.c, object.c, proc.c, variable.c, vm_eval.c, vm_method.c | 
Overview
A Module is a collection of methods and constants. The methods in a module may be instance methods or module methods. Instance methods appear as methods in a class when the module is included, module methods do not. Conversely, module methods may be called without creating an encapsulating object, while instance methods may not. (See #module_function.)
In the descriptions that follow, the parameter sym refers to a symbol, which is either a quoted string or a ::Symbol (such as :name).
module Mod
  include Math
  CONST = 1
  def meth
    #  ...
  end
end
Mod.class              #=> Module
Mod.constants          #=> [:CONST, :PI, :E]
Mod.instance_methods   #=> [:meth]Class Method Summary
- 
    
      .constants  ⇒ Array 
    
    In the first form, returns an array of the names of all constants accessible from the point of call. 
- 
    
      .nesting  ⇒ Array 
    
    Returns the list of Modulesnested at the point of call.
- 
    
      .new  ⇒ mod 
    
    constructor
    Creates a new anonymous module. 
- 
    
      .used_modules  ⇒ Array 
    
    Returns an array of all modules used in the current scope. 
Instance Attribute Summary
- 
    
      #singleton_class?  ⇒ Boolean 
    
    readonly
    Returns trueif mod is a singleton class orfalseif it is an ordinary class or module.
Instance Method Summary
- 
    
      #<(other)  ⇒ true, ... 
    
    Returns true if mod is a subclass of other. 
- 
    
      #<=(other)  ⇒ true, ... 
    
    Returns true if mod is a subclass of other or is the same as other. 
- 
    
      #<=>(other_module)  ⇒ 1, ... 
    
    Comparison—Returns -1, 0, +1 or nil depending on whether moduleincludesother_module, they are the same, or ifmoduleis included byother_module.
- 
    
      #==(other)  ⇒ Boolean 
    
    Alias for Object#eql?. 
- 
    
      #===(obj)  ⇒ Boolean 
    
    Case Equality—Returns trueif obj is an instance of mod or an instance of one of mod’s descendants.
- 
    
      #>(other)  ⇒ true, ... 
    
    Returns true if mod is an ancestor of other. 
- 
    
      #>=(other)  ⇒ true, ... 
    
    Returns true if mod is an ancestor of other, or the two modules are the same. 
- 
    
      #alias_method(new_name, old_name)  ⇒ Symbol 
    
    Makes new_name a new copy of the method old_name. 
- 
    
      #ancestors  ⇒ Array 
    
    Returns a list of modules included/prepended in mod (including mod itself). 
- 
    
      #attr(name, ...)  ⇒ Array 
    
    The first form is equivalent to #attr_reader. 
- 
    
      #attr_accessor(symbol, ...)  ⇒ Array 
    
    Defines a named attribute for this module, where the name is symbol. id2name, creating an instance variable (@name) and a corresponding access method to read it.
- 
    
      #attr_reader(symbol, ...)  ⇒ Array 
    
    Creates instance variables and corresponding methods that return the value of each instance variable. 
- 
    
      #attr_writer(symbol, ...)  ⇒ Array 
    
    Creates an accessor method to allow assignment to the attribute symbol .id2name.
- 
    
      #autoload(module, filename)  ⇒ nil 
    
    Registers filename to be loaded (using Kernel.require) the first time that module (which may be a ::Stringor a symbol) is accessed in the namespace of mod.
- 
    
      #autoload?(name, inherit = true)  ⇒ String? 
    
    Returns filename to be loaded if name is registered as #autoload in the namespace of mod or one of its ancestors. 
- 
    
      #class_eval(string [, filename [, lineno]])  ⇒ Object 
      (also: #module_eval)
    
    Evaluates the string or block in the context of mod, except that when a block is given, constant/class variable lookup is not affected. 
- 
    
      #class_exec(arg...) {|var...| ... } ⇒ Object 
      (also: #module_exec)
    
    Evaluates the given block in the context of the class/module. 
- 
    
      #class_variable_defined?(symbol)  ⇒ Boolean 
    
    Returns trueif the given class variable is defined in obj.
- 
    
      #class_variable_get(symbol)  ⇒ Object 
    
    Returns the value of the given class variable (or throws a ::NameErrorexception).
- 
    
      #class_variable_set(symbol, obj)  ⇒ Object 
    
    Sets the class variable named by symbol to the given object. 
- 
    
      #class_variables(inherit = true)  ⇒ Array 
    
    Returns an array of the names of class variables in mod. 
- 
    
      #const_defined?(sym, inherit = true)  ⇒ Boolean 
    
    Says whether mod or its ancestors have a constant with the given name: 
- 
    
      #const_get(sym, inherit = true)  ⇒ Object 
    
    Checks for a constant with the given name in mod. 
- 
    
      #const_missing(sym)  ⇒ Object 
    
    Invoked when a reference is made to an undefined constant in mod. 
- 
    
      #const_set(sym, obj)  ⇒ Object 
    
    Sets the named constant to the given object, returning that object. 
- 
    
      #const_source_location(sym, inherit = true)  ⇒ Array, Integer 
    
    Returns the Ruby source filename and line number containing the definition of the constant specified. 
- 
    
      #constants(inherit = true)  ⇒ Array 
    
    Returns an array of the names of the constants accessible in mod. 
- 
    
      #define_method(symbol, method)  ⇒ Symbol 
    
    Defines an instance method in the receiver. 
- 
    
      #deprecate_constant(symbol, ...)  ⇒ mod 
    
    Makes a list of existing constants deprecated. 
- 
    
      #freeze  ⇒ mod 
    
    Prevents further modifications to mod. 
- 
    
      #include(module, ...)  ⇒ self 
    
    Invokes #append_features on each parameter in reverse order. 
- 
    
      #include?(module)  ⇒ Boolean 
    
    Returns trueif module is included or prepended in mod or one of mod’s ancestors.
- 
    
      #included_modules  ⇒ Array 
    
    Returns the list of modules included or prepended in mod or one of mod’s ancestors. 
- 
    
      #inspect  ⇒ String 
    
    Alias for #to_s. 
- 
    
      #instance_method(symbol)  ⇒ unbound_method 
    
    Returns an ::UnboundMethodrepresenting the given instance method in mod.
- 
    
      #instance_methods(include_super = true)  ⇒ Array 
    
    Returns an array containing the names of the public and protected instance methods in the receiver. 
- 
    
      #method_defined?(symbol, inherit = true)  ⇒ Boolean 
    
    Returns trueif the named method is defined by mod.
- 
    
      #module_eval(string [, filename [, lineno]])  ⇒ Object 
    
    Alias for #class_eval. 
- 
    
      #module_exec(arg...) {|var...| ... } ⇒ Object 
    
    Alias for #class_exec. 
- 
    
      #name  ⇒ String 
    
    Returns the name of the module mod. 
- 
    
      #prepend(module, ...)  ⇒ self 
    
    Invokes #prepend_features on each parameter in reverse order. 
- 
    
      #private_class_method(symbol, ...)  ⇒ mod 
    
    Makes existing class methods private. 
- 
    
      #private_constant(symbol, ...)  ⇒ mod 
    
    Makes a list of existing constants private. 
- 
    
      #private_instance_methods(include_super = true)  ⇒ Array 
    
    Returns a list of the private instance methods defined in mod. 
- 
    
      #private_method_defined?(symbol, inherit = true)  ⇒ Boolean 
    
    Returns trueif the named private method is defined by mod.
- 
    
      #protected_instance_methods(include_super = true)  ⇒ Array 
    
    Returns a list of the protected instance methods defined in mod. 
- 
    
      #protected_method_defined?(symbol, inherit = true)  ⇒ Boolean 
    
    Returns trueif the named protected method is defined mod.
- 
    
      #public_class_method(symbol, ...)  ⇒ mod 
    
    Makes a list of existing class methods public. 
- 
    
      #public_constant(symbol, ...)  ⇒ mod 
    
    Makes a list of existing constants public. 
- 
    
      #public_instance_method(symbol)  ⇒ unbound_method 
    
    Similar to instance_method, searches public method only. 
- 
    
      #public_instance_methods(include_super = true)  ⇒ Array 
    
    Returns a list of the public instance methods defined in mod. 
- 
    
      #public_method_defined?(symbol, inherit = true)  ⇒ Boolean 
    
    Returns trueif the named public method is defined by mod.
- 
    
      #remove_class_variable(sym)  ⇒ Object 
    
    Removes the named class variable from the receiver, returning that variable’s value. 
- 
    
      #remove_method(symbol)  ⇒ self 
    
    Removes the method identified by symbol from the current class. 
- 
    
      #to_s  ⇒ String 
      (also: #inspect)
    
    Returns a string representing this module or class. 
- 
    
      #undef_method(symbol)  ⇒ self 
    
    Prevents the current class from responding to calls to the named method. 
- 
    
      #append_features(mod)  ⇒ mod 
    
    private
    When this module is included in another, Ruby calls #append_features in this module, passing it the receiving module in mod. 
- 
    
      #extend_object(obj)  ⇒ Object 
    
    private
    Extends the specified object by adding this module’s constants and methods (which are added as singleton methods). 
- 
    
      #extended(_y)  
      (also: #prepended, #method_added, #method_removed, #method_undefined)
    
    private
    Alias for Class#inherited. 
- 
    
      #extended(symbol)  
    
    private
    Alias for Class#inherited. 
- 
    
      #method_added(symbol)  
    
    private
    Alias for #extended. 
- 
    
      #method_removed(symbol)  
    
    private
    Alias for #extended. 
- 
    
      #method_undefined(symbol)  
    
    private
    Alias for #extended. 
- 
    
      #module_function(symbol, ...)  ⇒ self 
    
    private
    Creates module functions for the named methods. 
- 
    
      #prepend_features(mod)  ⇒ mod 
    
    private
    When this module is prepended in another, Ruby calls #prepend_features in this module, passing it the receiving module in mod. 
- 
    
      #prepended(symbol)  
    
    private
    Alias for #extended. 
- 
    
      #private  ⇒ self 
    
    private
    With no arguments, sets the default visibility for subsequently defined methods to private. 
- 
    
      #protected  ⇒ self 
    
    private
    With no arguments, sets the default visibility for subsequently defined methods to protected. 
- 
    
      #public  ⇒ self 
    
    private
    With no arguments, sets the default visibility for subsequently defined methods to public. 
- 
    
      #refine(mod)  ⇒ Module 
    
    private
    Refine mod in the receiver. 
- 
    
      #remove_const(sym)  ⇒ Object 
    
    private
    Removes the definition of the given constant, returning that constant’s previous value. 
- 
    
      #ruby2_keywords(method_name, ...)  ⇒ nil 
    
    private
    For the given method names, marks the method as passing keywords through a normal argument splat. 
- 
    
      #using(module)  ⇒ self 
    
    private
    Import class refinements from module into the current class or module definition. 
- #initialize_clone(*args) Internal use only
- #initialize_copy(orig) Internal use only
Constructor Details
    
      .new  ⇒ mod 
      .new {|mod| ... } ⇒ mod 
    
  
mod 
      .new {|mod| ... } ⇒ mod 
    Creates a new anonymous module. If a block is given, it is passed the module object, and the block is evaluated in the context of this module like #module_eval.
fred = Module.new do
  def meth1
    "hello"
  end
  def meth2
    "bye"
  end
end
a = "my string"
a.extend(fred)   #=> "my string"
a.meth1          #=> "hello"
a.meth2          #=> "bye"Assign the module to a constant (name starting uppercase) if you want to treat it like a regular module.
# File 'object.c', line 1911
static VALUE
rb_mod_initialize(VALUE module)
{
    if (rb_block_given_p()) {
	rb_mod_module_exec(1, &module, module);
    }
    return Qnil;
}
  Class Method Details
In the first form, returns an array of the names of all constants accessible from the point of call. This list includes the names of all modules and classes defined in the global scope.
Module.constants.first(4)
   # => [:ARGF, :ARGV, :ArgumentError, :Array]
Module.constants.include?(:SEEK_SET)   # => false
class IO
  Module.constants.include?(:SEEK_SET) # => true
endThe second form calls the instance method constants.
# File 'eval.c', line 440
static VALUE
rb_mod_s_constants(int argc, VALUE *argv, VALUE mod)
{
    const rb_cref_t *cref = rb_vm_cref();
    VALUE klass;
    VALUE cbase = 0;
    void *data = 0;
    if (argc > 0 || mod != rb_cModule) {
	return rb_mod_constants(argc, argv, mod);
    }
    while (cref) {
	klass = CREF_CLASS(cref);
	if (!CREF_PUSHED_BY_EVAL(cref) &&
	    !NIL_P(klass)) {
	    data = rb_mod_const_at(CREF_CLASS(cref), data);
	    if (!cbase) {
		cbase = klass;
	    }
	}
	cref = CREF_NEXT(cref);
    }
    if (cbase) {
	data = rb_mod_const_of(cbase, data);
    }
    return rb_const_list(data);
}
  .nesting ⇒ Array
Returns the list of Modules nested at the point of call.
module M1
  module M2
    $a = Module.nesting
  end
end
$a           #=> [M1::M2, M1]
$a[0].name   #=> "M1::M2"# File 'eval.c', line 401
static VALUE
rb_mod_nesting(VALUE _)
{
    VALUE ary = rb_ary_new();
    const rb_cref_t *cref = rb_vm_cref();
    while (cref && CREF_NEXT(cref)) {
	VALUE klass = CREF_CLASS(cref);
	if (!CREF_PUSHED_BY_EVAL(cref) &&
	    !NIL_P(klass)) {
	    rb_ary_push(ary, klass);
	}
	cref = CREF_NEXT(cref);
    }
    return ary;
}
  .used_modules ⇒ Array
# File 'eval.c', line 1683
static VALUE
rb_mod_s_used_modules(VALUE _)
{
    const rb_cref_t *cref = rb_vm_cref();
    VALUE ary = rb_ary_new();
    while (cref) {
	if (!NIL_P(CREF_REFINEMENTS(cref))) {
	    rb_hash_foreach(CREF_REFINEMENTS(cref), used_modules_i, ary);
	}
	cref = CREF_NEXT(cref);
    }
    return rb_funcall(ary, rb_intern("uniq"), 0);
}
  Instance Attribute Details
    #singleton_class?  ⇒ Boolean  (readonly)  
Returns true if mod is a singleton class or false if it is an ordinary class or module.
class C
end
C.singleton_class?                  #=> false
C.singleton_class.singleton_class?  #=> true# File 'object.c', line 3040
static VALUE
rb_mod_singleton_p(VALUE klass)
{
    if (RB_TYPE_P(klass, T_CLASS) && FL_TEST(klass, FL_SINGLETON))
	return Qtrue;
    return Qfalse;
}
  Instance Method Details
    #<(other)  ⇒ true, ...   
Returns true if mod is a subclass of 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”.)
# File 'object.c', line 1792
static VALUE
rb_mod_lt(VALUE mod, VALUE arg)
{
    if (mod == arg) return Qfalse;
    return rb_class_inherited_p(mod, arg);
}
  
    #<=(other)  ⇒ true, ...   
Returns true if mod is a subclass 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”.)
# File 'object.c', line 1764
VALUE
rb_class_inherited_p(VALUE mod, VALUE arg)
{
    if (mod == arg) return Qtrue;
    if (!CLASS_OR_MODULE_P(arg) && !RB_TYPE_P(arg, T_ICLASS)) {
	rb_raise(rb_eTypeError, "compared with non class/module");
    }
    if (class_search_ancestor(mod, RCLASS_ORIGIN(arg))) {
	return Qtrue;
    }
    /* not mod < arg; check if mod > arg */
    if (class_search_ancestor(arg, mod)) {
	return Qfalse;
    }
    return Qnil;
}
  
    #<=>(other_module)  ⇒ 1, ...   
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.
# File 'object.c', line 1852
static VALUE
rb_mod_cmp(VALUE mod, VALUE arg)
{
    VALUE cmp;
    if (mod == arg) return INT2FIX(0);
    if (!CLASS_OR_MODULE_P(arg)) {
	return Qnil;
    }
    cmp = rb_class_inherited_p(mod, arg);
    if (NIL_P(cmp)) return Qnil;
    if (cmp) {
	return INT2FIX(-1);
    }
    return INT2FIX(1);
}
  
    #==(other)  ⇒ Boolean   
Alias for Object#eql?. Equality — At the ::Object level, #== returns true only if obj and other are the same object.  Typically, this method is overridden in descendant classes to provide class-specific meaning.
Unlike #==, the #equal? method should never be overridden by subclasses as it is used to determine object identity (that is, a.equal?(b) if and only if a is the same object as b):
obj = "a"
other = obj.dup
obj == other      #=> true
obj.equal? other  #=> false
obj.equal? obj    #=> trueThe #eql? method returns true if obj and other refer to the same hash key.  This is used by ::Hash to test members for equality.  For any pair of objects where #eql? returns true, the #hash value of both objects must be equal. So any subclass that overrides #eql? should also override #hash appropriately.
For objects of class ::Object, #eql?  is synonymous with #==.  Subclasses normally continue this tradition by aliasing #eql? to their overridden #== method, but there are exceptions. ::Numeric types, for example, perform type conversion across #==, but not across #eql?, so:
1 == 1.0     #=> true
1.eql? 1.0   #=> false
    #===(obj)  ⇒ Boolean   
Case Equality—Returns true if obj is an instance of mod or an instance of one of mod’s descendants. Of limited use for modules, but can be used in case statements to classify objects by class.
# File 'object.c', line 1738
static VALUE
rb_mod_eqq(VALUE mod, VALUE arg)
{
    return rb_obj_is_kind_of(arg, mod);
}
  
    #>(other)  ⇒ true, ...   
Returns true if mod is an ancestor of 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”.)
# File 'object.c', line 1833
static VALUE
rb_mod_gt(VALUE mod, VALUE arg)
{
    if (mod == arg) return Qfalse;
    return rb_mod_ge(mod, arg);
}
  
    #>=(other)  ⇒ true, ...   
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”.)
# File 'object.c', line 1812
static VALUE
rb_mod_ge(VALUE mod, VALUE arg)
{
    if (!CLASS_OR_MODULE_P(arg)) {
	rb_raise(rb_eTypeError, "compared with non class/module");
    }
    return rb_class_inherited_p(arg, mod);
}
  #alias_method(new_name, old_name) ⇒ Symbol
Makes new_name a new copy of the method old_name. This can be used to retain access to methods that are overridden.
module Mod
  alias_method :orig_exit, :exit #=> :orig_exit
  def exit(code=0)
    puts "Exiting with code #{code}"
    orig_exit(code)
  end
end
include Mod
exit(99)produces:
Exiting with code 99# File 'vm_method.c', line 2001
static VALUE
rb_mod_alias_method(VALUE mod, VALUE newname, VALUE oldname)
{
    ID oldid = rb_check_id(&oldname);
    if (!oldid) {
	rb_print_undef_str(mod, oldname);
    }
    VALUE id = rb_to_id(newname);
    rb_alias(mod, id, oldid);
    return ID2SYM(id);
}
  #ancestors ⇒ Array
Returns a list of modules included/prepended in mod (including mod itself).
module Mod
  include Math
  include Comparable
  prepend Enumerable
end
Mod.ancestors        #=> [Enumerable, Mod, Comparable, Math]
Math.ancestors       #=> [Math]
Enumerable.ancestors #=> [Enumerable]# File 'class.c', line 1300
VALUE
rb_mod_ancestors(VALUE mod)
{
    VALUE p, ary = rb_ary_new();
    for (p = mod; p; p = RCLASS_SUPER(p)) {
        if (p != RCLASS_ORIGIN(p)) continue;
	if (BUILTIN_TYPE(p) == T_ICLASS) {
	    rb_ary_push(ary, RBASIC(p)->klass);
	}
        else {
	    rb_ary_push(ary, p);
	}
    }
    return ary;
}
  
    #append_features(mod)  ⇒ mod  (private)  
When this module is included in another, Ruby calls #append_features in this module, passing it the receiving module in mod. Ruby’s default implementation is to add the constants, methods, and module variables of this module to mod if this module has not already been added to mod or one of its ancestors. See also #include.
# File 'eval.c', line 1296
static VALUE
rb_mod_append_features(VALUE module, VALUE include)
{
    if (!CLASS_OR_MODULE_P(include)) {
	Check_Type(include, T_CLASS);
    }
    rb_include_module(include, module);
    return module;
}
  The first form is equivalent to #attr_reader. The second form is equivalent to attr_accessor(name) but deprecated. The last form is equivalent to attr_reader(name) but deprecated. Returns an array of defined method names as symbols.
# File 'object.c', line 2298
VALUE
rb_mod_attr(int argc, VALUE *argv, VALUE klass)
{
    if (argc == 2 && (argv[1] == Qtrue || argv[1] == Qfalse)) {
	ID id = id_for_attr(klass, argv[0]);
	VALUE names = rb_ary_new();
	rb_category_warning(RB_WARN_CATEGORY_DEPRECATED, "optional boolean argument is obsoleted");
	rb_attr(klass, id, 1, RTEST(argv[1]), TRUE);
	rb_ary_push(names, ID2SYM(id));
	if (argv[1] == Qtrue) rb_ary_push(names, ID2SYM(rb_id_attrset(id)));
	return names;
    }
    return rb_mod_attr_reader(argc, argv, klass);
}
  Defines a named attribute for this module, where the name is symbol.id2name, creating an instance variable (@name) and a corresponding access method to read it. Also creates a method called name= to set the attribute. ::String arguments are converted to symbols. Returns an array of defined method names as symbols.
module Mod
  attr_accessor(:one, :two) #=> [:one, :one=, :two, :two=]
end
Mod.instance_methods.sort   #=> [:one, :one=, :two, :two=]# File 'object.c', line 2357
static VALUE
rb_mod_attr_accessor(int argc, VALUE *argv, VALUE klass)
{
    int i;
    VALUE names = rb_ary_new2(argc * 2);
    for (i=0; i<argc; i++) {
	ID id = id_for_attr(klass, argv[i]);
	rb_attr(klass, id, TRUE, TRUE, TRUE);
	rb_ary_push(names, ID2SYM(id));
	rb_ary_push(names, ID2SYM(rb_id_attrset(id)));
    }
    return names;
}
  Creates instance variables and corresponding methods that return the value of each instance variable. Equivalent to calling “attr:name” on each name in turn. ::String arguments are converted to symbols. Returns an array of defined method names as symbols.
# File 'object.c', line 2269
static VALUE
rb_mod_attr_reader(int argc, VALUE *argv, VALUE klass)
{
    int i;
    VALUE names = rb_ary_new2(argc);
    for (i=0; i<argc; i++) {
	ID id = id_for_attr(klass, argv[i]);
	rb_attr(klass, id, TRUE, FALSE, TRUE);
	rb_ary_push(names, ID2SYM(id));
    }
    return names;
}
  Creates an accessor method to allow assignment to the attribute symbol.id2name. ::String arguments are converted to symbols. Returns an array of defined method names as symbols.
# File 'object.c', line 2325
static VALUE
rb_mod_attr_writer(int argc, VALUE *argv, VALUE klass)
{
    int i;
    VALUE names = rb_ary_new2(argc);
    for (i=0; i<argc; i++) {
	ID id = id_for_attr(klass, argv[i]);
	rb_attr(klass, id, FALSE, TRUE, TRUE);
	rb_ary_push(names, ID2SYM(rb_id_attrset(id)));
    }
    return names;
}
  
    #autoload(module, filename)  ⇒ nil   
Registers filename to be loaded (using Kernel.require) the first time that module (which may be a ::String or a symbol) is accessed in the namespace of mod.
module A
end
A.autoload(:B, "b")
A::B.doit            # autoloads "b"# File 'load.c', line 1243
static VALUE
rb_mod_autoload(VALUE mod, VALUE sym, VALUE file)
{
    ID id = rb_to_id(sym);
    FilePathValue(file);
    rb_autoload_str(mod, id, file);
    return Qnil;
}
  #autoload?(name, inherit = true) ⇒ String?
Returns filename to be loaded if name is registered as #autoload in the namespace of mod or one of its ancestors.
module A
end
A.autoload(:B, "b")
A.autoload?(:B)            #=> "b"If inherit is false, the lookup only checks the autoloads in the receiver:
class A
  autoload :CONST, "const.rb"
end
class B < A
end
B.autoload?(:CONST)          #=> "const.rb", found in A (ancestor)
B.autoload?(:CONST, false)   #=> nil, not found in B itself# File 'load.c', line 1279
static VALUE
rb_mod_autoload_p(int argc, VALUE *argv, VALUE mod)
{
    int recur = (rb_check_arity(argc, 1, 2) == 1) ? TRUE : RTEST(argv[1]);
    VALUE sym = argv[0];
    ID id = rb_check_id(&sym);
    if (!id) {
	return Qnil;
    }
    return rb_autoload_at_p(mod, id, recur);
}
  
    
      #class_eval(string [, filename [, lineno]])  ⇒ Object 
      #class_eval {|mod| ... } ⇒ Object 
      #module_eval(string [, filename [, lineno]])  ⇒ Object 
      #module_eval {|mod| ... } ⇒ Object 
    
    Also known as: #module_eval
  
Evaluates the string or block in the context of mod, except that when a block is given, constant/class variable lookup is not affected. This can be used to add methods to a class. #module_eval returns the result of evaluating its argument. The optional filename and lineno parameters set the text for error messages.
class Thing
end
a = %q{def hello() "Hello there!" end}
Thing.module_eval(a)
puts Thing.new.hello()
Thing.module_eval("invalid code", "dummy", 123)produces:
Hello there!
dummy:123:in `module_eval': undefined local variable
    or method `code' for Thing:Class# File 'vm_eval.c', line 2157
static VALUE
rb_mod_module_eval_internal(int argc, const VALUE *argv, VALUE mod)
{
    return specific_eval(argc, argv, mod, mod, RB_PASS_CALLED_KEYWORDS);
}
  Also known as: #module_exec
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()produces:
Hello there!# File 'vm_eval.c', line 2191
static VALUE
rb_mod_module_exec_internal(int argc, const VALUE *argv, VALUE mod)
{
    return yield_under(mod, mod, argc, argv, RB_PASS_CALLED_KEYWORDS);
}
  
    
      #class_variable_defined?(symbol)  ⇒ Boolean 
      #class_variable_defined?(string)  ⇒ Boolean 
    
  
Boolean 
      #class_variable_defined?(string)  ⇒ Boolean 
    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# File 'object.c', line 3016
static VALUE
rb_mod_cvar_defined(VALUE obj, VALUE iv)
{
    ID id = id_for_var(obj, iv, class);
    if (!id) {
	return Qfalse;
    }
    return rb_cvar_defined(obj, id);
}
  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# File 'object.c', line 2959
static VALUE
rb_mod_cvar_get(VALUE obj, VALUE iv)
{
    ID id = id_for_var(obj, iv, class);
    if (!id) {
	rb_name_err_raise("uninitialized class variable %1$s in %2$s",
			  obj, iv);
    }
    return rb_cvar_get(obj, id);
}
  Sets the class variable named by symbol to the given object. If the class variable name is passed as a string, that string is converted to a symbol.
class Fred
  @@foo = 99
  def foo
    @@foo
  end
end
Fred.class_variable_set(:@@foo, 101)     #=> 101
Fred.new.foo                             #=> 101# File 'object.c', line 2991
static VALUE
rb_mod_cvar_set(VALUE obj, VALUE iv, VALUE val)
{
    ID id = id_for_var(obj, iv, class);
    if (!id) id = rb_intern_str(iv);
    rb_cvar_set(obj, id, val);
    return val;
}
  #class_variables(inherit = true) ⇒ Array
Returns an array of the names of class variables in mod. This includes the names of class variables in any included modules, unless the inherit parameter is set to false.
class One
  @@var1 = 1
end
class Two < One
  @@var2 = 2
end
One.class_variables          #=> [:@@var1]
Two.class_variables          #=> [:@@var2, :@@var1]
Two.class_variables(false)   #=> [:@@var2]# File 'variable.c', line 3511
VALUE
rb_mod_class_variables(int argc, const VALUE *argv, VALUE mod)
{
    bool inherit = true;
    st_table *tbl;
    if (rb_check_arity(argc, 0, 1)) inherit = RTEST(argv[0]);
    if (inherit) {
	tbl = mod_cvar_of(mod, 0);
    }
    else {
	tbl = mod_cvar_at(mod, 0);
    }
    return cvar_list(tbl);
}
  
    
      #const_defined?(sym, inherit = true)  ⇒ Boolean 
      #const_defined?(str, inherit = true)  ⇒ Boolean 
    
  
Boolean 
      #const_defined?(str, inherit = true)  ⇒ Boolean 
    Says whether mod or its ancestors have a constant with the given name:
Float.const_defined?(:EPSILON)      #=> true, found in Float itself
Float.const_defined?("String")      #=> true, found in Object (ancestor)
BasicObject.const_defined?(:Hash)   #=> falseIf mod is a Module, additionally ::Object and its ancestors are checked:
Math.const_defined?(:String)   #=> true, found in ObjectIn each of the checked classes or modules, if the constant is not present but there is an autoload for it, true is returned directly without autoloading:
module Admin
  autoload :User, 'admin/user'
end
Admin.const_defined?(:User)   #=> trueIf the constant is not found the callback #const_missing is not called and the method returns false.
If inherit is false, the lookup only checks the constants in the receiver:
IO.const_defined?(:SYNC)          #=> true, found in File::Constants (ancestor)
IO.const_defined?(:SYNC, false)   #=> false, not found in IO itselfIn this case, the same logic for autoloading applies.
If the argument is not a valid constant name a ::NameError is raised with the message “wrong constant name name”:
Hash.const_defined? 'foobar'   #=> NameError: wrong constant name foobar# File 'object.c', line 2586
static VALUE
rb_mod_const_defined(int argc, VALUE *argv, VALUE mod)
{
    VALUE name, recur;
    rb_encoding *enc;
    const char *pbeg, *p, *path, *pend;
    ID id;
    rb_check_arity(argc, 1, 2);
    name = argv[0];
    recur = (argc == 1) ? Qtrue : argv[1];
    if (SYMBOL_P(name)) {
	if (!rb_is_const_sym(name)) goto wrong_name;
	id = rb_check_id(&name);
	if (!id) return Qfalse;
	return RTEST(recur) ? rb_const_defined(mod, id) : rb_const_defined_at(mod, id);
    }
    path = StringValuePtr(name);
    enc = rb_enc_get(name);
    if (!rb_enc_asciicompat(enc)) {
	rb_raise(rb_eArgError, "invalid class path encoding (non ASCII)");
    }
    pbeg = p = path;
    pend = path + RSTRING_LEN(name);
    if (p >= pend || !*p) {
        goto wrong_name;
    }
    if (p + 2 < pend && p[0] == ':' && p[1] == ':') {
	mod = rb_cObject;
	p += 2;
	pbeg = p;
    }
    while (p < pend) {
	VALUE part;
	long len, beglen;
	while (p < pend && *p != ':') p++;
	if (pbeg == p) goto wrong_name;
	id = rb_check_id_cstr(pbeg, len = p-pbeg, enc);
	beglen = pbeg-path;
	if (p < pend && p[0] == ':') {
	    if (p + 2 >= pend || p[1] != ':') goto wrong_name;
	    p += 2;
	    pbeg = p;
	}
	if (!id) {
	    part = rb_str_subseq(name, beglen, len);
	    OBJ_FREEZE(part);
	    if (!rb_is_const_name(part)) {
		name = part;
		goto wrong_name;
	    }
	    else {
		return Qfalse;
	    }
	}
	if (!rb_is_const_id(id)) {
	    name = ID2SYM(id);
	    goto wrong_name;
	}
#if 0
        mod = rb_const_search(mod, id, beglen > 0 || !RTEST(recur), RTEST(recur), FALSE);
        if (mod == Qundef) return Qfalse;
#else
        if (!RTEST(recur)) {
	    if (!rb_const_defined_at(mod, id))
		return Qfalse;
            if (p == pend) return Qtrue;
	    mod = rb_const_get_at(mod, id);
	}
        else if (beglen == 0) {
            if (!rb_const_defined(mod, id))
                return Qfalse;
            if (p == pend) return Qtrue;
            mod = rb_const_get(mod, id);
        }
        else {
            if (!rb_const_defined_from(mod, id))
                return Qfalse;
            if (p == pend) return Qtrue;
            mod = rb_const_get_from(mod, id);
        }
#endif
	if (p < pend && !RB_TYPE_P(mod, T_MODULE) && !RB_TYPE_P(mod, T_CLASS)) {
	    rb_raise(rb_eTypeError, "%"PRIsVALUE" does not refer to class/module",
		     QUOTE(name));
	}
    }
    return Qtrue;
  wrong_name:
    rb_name_err_raise(wrong_constant_name, mod, name);
    UNREACHABLE_RETURN(Qundef);
}
  Checks for a constant with the given name in mod. If inherit is set, the lookup will also search the ancestors (and ::Object if mod is a Module).
The value of the constant is returned if a definition is found, otherwise a ::NameError is raised.
Math.const_get(:PI)   #=> 3.14159265358979This method will recursively look up constant names if a namespaced class name is provided. For example:
module Foo; class Bar; end end
Object.const_get 'Foo::Bar'The inherit flag is respected on each lookup.  For example:
module Foo
  class Bar
    VAL = 10
  end
  class Baz < Bar; end
end
Object.const_get 'Foo::Baz::VAL'         # => 10
Object.const_get 'Foo::Baz::VAL', false  # => NameErrorIf the argument is not a valid constant name a ::NameError will be raised with a warning “wrong constant name”.
Object.const_get 'foobar' #=> NameError: wrong constant name foobar# File 'object.c', line 2413
static VALUE
rb_mod_const_get(int argc, VALUE *argv, VALUE mod)
{
    VALUE name, recur;
    rb_encoding *enc;
    const char *pbeg, *p, *path, *pend;
    ID id;
    rb_check_arity(argc, 1, 2);
    name = argv[0];
    recur = (argc == 1) ? Qtrue : argv[1];
    if (SYMBOL_P(name)) {
	if (!rb_is_const_sym(name)) goto wrong_name;
	id = rb_check_id(&name);
	if (!id) return rb_const_missing(mod, name);
	return RTEST(recur) ? rb_const_get(mod, id) : rb_const_get_at(mod, id);
    }
    path = StringValuePtr(name);
    enc = rb_enc_get(name);
    if (!rb_enc_asciicompat(enc)) {
	rb_raise(rb_eArgError, "invalid class path encoding (non ASCII)");
    }
    pbeg = p = path;
    pend = path + RSTRING_LEN(name);
    if (p >= pend || !*p) {
        goto wrong_name;
    }
    if (p + 2 < pend && p[0] == ':' && p[1] == ':') {
	mod = rb_cObject;
	p += 2;
	pbeg = p;
    }
    while (p < pend) {
	VALUE part;
	long len, beglen;
	while (p < pend && *p != ':') p++;
	if (pbeg == p) goto wrong_name;
	id = rb_check_id_cstr(pbeg, len = p-pbeg, enc);
	beglen = pbeg-path;
	if (p < pend && p[0] == ':') {
	    if (p + 2 >= pend || p[1] != ':') goto wrong_name;
	    p += 2;
	    pbeg = p;
	}
	if (!RB_TYPE_P(mod, T_MODULE) && !RB_TYPE_P(mod, T_CLASS)) {
	    rb_raise(rb_eTypeError, "%"PRIsVALUE" does not refer to class/module",
		     QUOTE(name));
	}
	if (!id) {
	    part = rb_str_subseq(name, beglen, len);
	    OBJ_FREEZE(part);
	    if (!rb_is_const_name(part)) {
		name = part;
		goto wrong_name;
	    }
	    else if (!rb_method_basic_definition_p(CLASS_OF(mod), id_const_missing)) {
		part = rb_str_intern(part);
		mod = rb_const_missing(mod, part);
		continue;
	    }
	    else {
		rb_mod_const_missing(mod, part);
	    }
	}
	if (!rb_is_const_id(id)) {
	    name = ID2SYM(id);
	    goto wrong_name;
	}
#if 0
        mod = rb_const_get_0(mod, id, beglen > 0 || !RTEST(recur), RTEST(recur), FALSE);
#else
        if (!RTEST(recur)) {
            mod = rb_const_get_at(mod, id);
        }
        else if (beglen == 0) {
            mod = rb_const_get(mod, id);
        }
        else {
            mod = rb_const_get_from(mod, id);
        }
#endif
    }
    return mod;
  wrong_name:
    rb_name_err_raise(wrong_constant_name, mod, name);
    UNREACHABLE_RETURN(Qundef);
}
  #const_missing(sym) ⇒ Object
Invoked when a reference is made to an undefined constant in mod. It is passed a symbol for the undefined constant, and returns a value to be used for that constant. The following code is an example of the same:
def Foo.const_missing(name)
  name # return the constant name as Symbol
end
Foo::UNDEFINED_CONST    #=> :UNDEFINED_CONST: symbol returnedIn the next example when a reference is made to an undefined constant, it attempts to load a file whose name is the lowercase version of the constant (thus class Fred is assumed to be in file fred.rb).  If found, it returns the loaded class. It therefore implements an autoload feature similar to Kernel.autoload and #autoload.
def Object.const_missing(name)
  @looked_for ||= {}
  str_name = name.to_s
  raise "Class not found: #{name}" if @looked_for[str_name]
  @looked_for[str_name] = 1
  file = str_name.downcase
  require file
  klass = const_get(name)
  return klass if klass
  raise "Class not found: #{name}"
end# File 'variable.c', line 1959
VALUE
rb_mod_const_missing(VALUE klass, VALUE name)
{
    VALUE ref = GET_EC()->private_const_reference;
    rb_vm_pop_cfunc_frame();
    if (ref) {
	rb_name_err_raise("private constant %2$s::%1$s referenced",
			  ref, name);
    }
    uninitialized_constant(klass, name);
    UNREACHABLE_RETURN(Qnil);
}
  Sets the named constant to the given object, returning that object. Creates a new constant if no constant with the given name previously existed.
Math.const_set("HIGH_SCHOOL_PI", 22.0/7.0)   #=> 3.14285714285714
Math::HIGH_SCHOOL_PI - Math::PI              #=> 0.00126448926734968If sym or str is not a valid constant name a ::NameError will be raised with a warning “wrong constant name”.
Object.const_set('foobar', 42) #=> NameError: wrong constant name foobar# File 'object.c', line 2535
static VALUE
rb_mod_const_set(VALUE mod, VALUE name, VALUE value)
{
    ID id = id_for_var(mod, name, const);
    if (!id) id = rb_intern_str(name);
    rb_const_set(mod, id, value);
    return value;
}
  Returns the Ruby source filename and line number containing the definition of the constant specified. If the named constant is not found, nil is returned. If the constant is found, but its source location can not be extracted (constant is defined in C code), empty array is returned.
inherit specifies whether to lookup in mod.ancestors (true by default).
# test.rb:
class A         # line 1
  C1 = 1
  C2 = 2
end
module M        # line 6
  C3 = 3
end
class B < A     # line 10
  include M
  C4 = 4
end
class A # continuation of A definition
  C2 = 8 # constant redefinition; warned yet allowed
end
p B.const_source_location('C4')           # => ["test.rb", 12]
p B.const_source_location('C3')           # => ["test.rb", 7]
p B.const_source_location('C1')           # => ["test.rb", 2]
p B.const_source_location('C3', false)    # => nil  -- don't lookup in ancestors
p A.const_source_location('C2')           # => ["test.rb", 16] -- actual (last) definition place
p Object.const_source_location('B')       # => ["test.rb", 10] -- top-level constant could be looked through Object
p Object.const_source_location('A')       # => ["test.rb", 1] -- class reopening is NOT considered new definition
p B.const_source_location('A')            # => ["test.rb", 1]  -- because Object is in ancestors
p M.const_source_location('A')            # => ["test.rb", 1]  -- Object is not ancestor, but additionally checked for modules
p Object.const_source_location('A::C1')   # => ["test.rb", 2]  -- nesting is supported
p Object.const_source_location('String')  # => []  -- constant is defined in C code# File 'object.c', line 2746
static VALUE
rb_mod_const_source_location(int argc, VALUE *argv, VALUE mod)
{
    VALUE name, recur, loc = Qnil;
    rb_encoding *enc;
    const char *pbeg, *p, *path, *pend;
    ID id;
    rb_check_arity(argc, 1, 2);
    name = argv[0];
    recur = (argc == 1) ? Qtrue : argv[1];
    if (SYMBOL_P(name)) {
        if (!rb_is_const_sym(name)) goto wrong_name;
        id = rb_check_id(&name);
        if (!id) return Qnil;
        return RTEST(recur) ? rb_const_source_location(mod, id) : rb_const_source_location_at(mod, id);
    }
    path = StringValuePtr(name);
    enc = rb_enc_get(name);
    if (!rb_enc_asciicompat(enc)) {
        rb_raise(rb_eArgError, "invalid class path encoding (non ASCII)");
    }
    pbeg = p = path;
    pend = path + RSTRING_LEN(name);
    if (p >= pend || !*p) {
        goto wrong_name;
    }
    if (p + 2 < pend && p[0] == ':' && p[1] == ':') {
        mod = rb_cObject;
        p += 2;
        pbeg = p;
    }
    while (p < pend) {
        VALUE part;
        long len, beglen;
        while (p < pend && *p != ':') p++;
        if (pbeg == p) goto wrong_name;
        id = rb_check_id_cstr(pbeg, len = p-pbeg, enc);
        beglen = pbeg-path;
        if (p < pend && p[0] == ':') {
            if (p + 2 >= pend || p[1] != ':') goto wrong_name;
            p += 2;
            pbeg = p;
        }
        if (!id) {
            part = rb_str_subseq(name, beglen, len);
            OBJ_FREEZE(part);
            if (!rb_is_const_name(part)) {
                name = part;
                goto wrong_name;
            }
            else {
                return Qnil;
            }
        }
        if (!rb_is_const_id(id)) {
            name = ID2SYM(id);
            goto wrong_name;
        }
        if (p < pend) {
            if (RTEST(recur)) {
                mod = rb_const_get(mod, id);
            }
            else {
                mod = rb_const_get_at(mod, id);
            }
            if (!RB_TYPE_P(mod, T_MODULE) && !RB_TYPE_P(mod, T_CLASS)) {
                rb_raise(rb_eTypeError, "%"PRIsVALUE" does not refer to class/module",
                         QUOTE(name));
            }
        }
        else {
            if (RTEST(recur)) {
                loc = rb_const_source_location(mod, id);
            }
            else {
                loc = rb_const_source_location_at(mod, id);
            }
            break;
        }
        recur = Qfalse;
    }
    return loc;
  wrong_name:
    rb_name_err_raise(wrong_constant_name, mod, name);
    UNREACHABLE_RETURN(Qundef);
}
  #constants(inherit = true) ⇒ Array
Returns an array of the names of the constants accessible in mod. This includes the names of constants in any included modules (example at start of section), unless the inherit parameter is set to false.
The implementation makes no guarantees about the order in which the constants are yielded.
IO.constants.include?(:SYNC)        #=> true
IO.constants(false).include?(:SYNC) #=> falseAlso see #const_defined?.
# File 'variable.c', line 2871
VALUE
rb_mod_constants(int argc, const VALUE *argv, VALUE mod)
{
    bool inherit = true;
    if (rb_check_arity(argc, 0, 1)) inherit = RTEST(argv[0]);
    if (inherit) {
	return rb_const_list(rb_mod_const_of(mod, 0));
    }
    else {
	return rb_local_constants(mod);
    }
}
  Defines an instance 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 the method parameter has parameters, they’re used as method parameters. This block is evaluated using #instance_eval.
class A
  def fred
    puts "In Fred"
  end
  def create_method(name, &block)
    self.class.define_method(name, &block)
  end
  define_method(:wilma) { puts "Charge it!" }
  define_method(:flint) {|name| puts "I'm #{name}!"}
end
class B < A
  define_method(:, instance_method(:fred))
end
a = B.new
a.
a.wilma
a.flint('Dino')
a.create_method(:betty) { p self }
a.bettyproduces:
In Fred
Charge it!
I'm Dino!
#<B:0x401b39e8># File 'proc.c', line 2170
static VALUE
rb_mod_define_method(int argc, VALUE *argv, VALUE mod)
{
    ID id;
    VALUE body;
    VALUE name;
    const rb_cref_t *cref = rb_vm_cref_in_context(mod, mod);
    const rb_scope_visibility_t default_scope_visi = {METHOD_VISI_PUBLIC, FALSE};
    const rb_scope_visibility_t *scope_visi = &default_scope_visi;
    int is_method = FALSE;
    if (cref) {
	scope_visi = CREF_SCOPE_VISI(cref);
    }
    rb_check_arity(argc, 1, 2);
    name = argv[0];
    id = rb_check_id(&name);
    if (argc == 1) {
	body = rb_block_lambda();
    }
    else {
	body = argv[1];
	if (rb_obj_is_method(body)) {
	    is_method = TRUE;
	}
	else if (rb_obj_is_proc(body)) {
	    is_method = FALSE;
	}
	else {
	    rb_raise(rb_eTypeError,
		     "wrong argument type %s (expected Proc/Method/UnboundMethod)",
		     rb_obj_classname(body));
	}
    }
    if (!id) id = rb_to_id(name);
    if (is_method) {
	struct METHOD *method = (struct METHOD *)DATA_PTR(body);
	if (method->me->owner != mod && !RB_TYPE_P(method->me->owner, T_MODULE) &&
	    !RTEST(rb_class_inherited_p(mod, method->me->owner))) {
	    if (FL_TEST(method->me->owner, FL_SINGLETON)) {
		rb_raise(rb_eTypeError,
			 "can't bind singleton method to a different class");
	    }
	    else {
		rb_raise(rb_eTypeError,
			 "bind argument must be a subclass of % "PRIsVALUE,
			 method->me->owner);
	    }
	}
	rb_method_entry_set(mod, id, method->me, scope_visi->method_visi);
	if (scope_visi->module_func) {
	    rb_method_entry_set(rb_singleton_class(mod), id, method->me, METHOD_VISI_PUBLIC);
	}
	RB_GC_GUARD(body);
    }
    else {
	VALUE procval = rb_proc_dup(body);
	if (vm_proc_iseq(procval) != NULL) {
	    rb_proc_t *proc;
	    GetProcPtr(procval, proc);
	    proc->is_lambda = TRUE;
	    proc->is_from_method = TRUE;
	}
	rb_add_method(mod, id, VM_METHOD_TYPE_BMETHOD, (void *)procval, scope_visi->method_visi);
	if (scope_visi->module_func) {
	    rb_add_method(rb_singleton_class(mod), id, VM_METHOD_TYPE_BMETHOD, (void *)body, METHOD_VISI_PUBLIC);
	}
    }
    return ID2SYM(id);
}
  
    #deprecate_constant(symbol, ...)  ⇒ mod   
Makes a list of existing constants deprecated. Attempt to refer to them will produce a warning.
module HTTP
  NotFound = Exception.new
  NOT_FOUND = NotFound # previous version of the library used this name
  deprecate_constant :NOT_FOUND
end
HTTP::NOT_FOUND
# warning: constant HTTP::NOT_FOUND is deprecated# File 'variable.c', line 3280
VALUE
rb_mod_deprecate_constant(int argc, const VALUE *argv, VALUE obj)
{
    set_const_visibility(obj, argc, argv, CONST_DEPRECATED, CONST_DEPRECATED);
    return obj;
}
  #extend_object(obj) ⇒ Object (private)
Extends the specified object by adding this module’s constants and methods (which are added as singleton methods). This is the callback method used by Object#extend.
module Picky
  def Picky.extend_object(o)
    if String === o
      puts "Can't add Picky to a String"
    else
      puts "Picky added to #{o.class}"
      super
    end
  end
end
(s = Array.new).extend Picky  # Call Object.extend
(s = "quick brown fox").extend Pickyproduces:
Picky added to Array
Can't add Picky to a String# File 'eval.c', line 1762
static VALUE
rb_mod_extend_object(VALUE mod, VALUE obj)
{
    rb_extend_object(obj, mod);
    return obj;
}
  #extended(_y) (private) Also known as: #prepended, #method_added, #method_removed, #method_undefined
Alias for Class#inherited. Callback invoked whenever the receiver is included in another module or class. This should be used in preference to #append_features if your code wants to perform some action when a module is included in another.
module A
  def A.included(mod)
    puts "#{self} included in #{mod}"
  end
end
module Enumerable
  include A
end
 # => prints "A included in Enumerable"
    #freeze  ⇒ mod   
Prevents further modifications to mod.
This method returns self.
# File 'object.c', line 1721
static VALUE
rb_mod_freeze(VALUE mod)
{
    rb_class_name(mod);
    return rb_obj_freeze(mod);
}
  
    #include(module, ...)  ⇒ self   
Invokes #append_features on each parameter in reverse order.
# File 'eval.c', line 1314
static VALUE
rb_mod_include(int argc, VALUE *argv, VALUE module)
{
    int i;
    ID id_append_features, id_included;
    CONST_ID(id_append_features, "append_features");
    CONST_ID(id_included, "included");
    rb_check_arity(argc, 1, UNLIMITED_ARGUMENTS);
    for (i = 0; i < argc; i++)
	Check_Type(argv[i], T_MODULE);
    while (argc--) {
	rb_funcall(argv[argc], id_append_features, 1, module);
	rb_funcall(argv[argc], id_included, 1, module);
    }
    return module;
}
  
    #include?(module)  ⇒ Boolean   
Returns true if module is included or prepended in mod or one of mod’s ancestors.
module A
end
class B
  include A
end
class C < B
end
B.include?(A)   #=> true
C.include?(A)   #=> true
A.include?(A)   #=> false# File 'class.c', line 1268
VALUE
rb_mod_include_p(VALUE mod, VALUE mod2)
{
    VALUE p;
    Check_Type(mod2, T_MODULE);
    for (p = RCLASS_SUPER(mod); p; p = RCLASS_SUPER(p)) {
        if (BUILTIN_TYPE(p) == T_ICLASS && !FL_TEST(p, RICLASS_IS_ORIGIN)) {
	    if (RBASIC(p)->klass == mod2) return Qtrue;
	}
    }
    return Qfalse;
}
  #extended(symbol) (private)
Alias for Class#inherited. Callback invoked whenever the receiver is included in another module or class. This should be used in preference to #append_features if your code wants to perform some action when a module is included in another.
module A
  def A.included(mod)
    puts "#{self} included in #{mod}"
  end
end
module Enumerable
  include A
end
 # => prints "A included in Enumerable"#included_modules ⇒ Array
# File 'class.c', line 1232
VALUE
rb_mod_included_modules(VALUE mod)
{
    VALUE ary = rb_ary_new();
    VALUE p;
    VALUE origin = RCLASS_ORIGIN(mod);
    for (p = RCLASS_SUPER(mod); p; p = RCLASS_SUPER(p)) {
        if (p != origin && RCLASS_ORIGIN(p) == p && BUILTIN_TYPE(p) == T_ICLASS) {
	    VALUE m = RBASIC(p)->klass;
	    if (RB_TYPE_P(m, T_MODULE))
		rb_ary_push(ary, m);
	}
    }
    return ary;
}
  #initialize_clone(*args)
# File 'object.c', line 1921
static VALUE
rb_mod_initialize_clone(int argc, VALUE* argv, VALUE clone)
{
    VALUE ret, orig, opts;
    rb_scan_args(argc, argv, "1:", &orig, &opts);
    ret = rb_obj_init_clone(argc, argv, clone);
    if (OBJ_FROZEN(orig))
        rb_class_name(clone);
    return ret;
}
  #initialize_copy(orig)
# File 'class.c', line 358
VALUE
rb_mod_init_copy(VALUE clone, VALUE orig)
{
    if (RB_TYPE_P(clone, T_CLASS)) {
        class_init_copy_check(clone, orig);
    }
    if (!OBJ_INIT_COPY(clone, orig)) return clone;
    /* cloned flag is refer at constant inline cache
     * see vm_get_const_key_cref() in vm_insnhelper.c
     */
    FL_SET(clone, RCLASS_CLONED);
    FL_SET(orig , RCLASS_CLONED);
    if (!FL_TEST(CLASS_OF(clone), FL_SINGLETON)) {
        RBASIC_SET_CLASS(clone, rb_singleton_class_clone(orig));
        rb_singleton_class_attached(RBASIC(clone)->klass, (VALUE)clone);
    }
    RCLASS_EXT(clone)->allocator = RCLASS_EXT(orig)->allocator;
    copy_tables(clone, orig);
    if (RCLASS_M_TBL(orig)) {
	struct clone_method_arg arg;
	arg.old_klass = orig;
	arg.new_klass = clone;
	RCLASS_M_TBL_INIT(clone);
	rb_id_table_foreach(RCLASS_M_TBL(orig), clone_method_i, &arg);
    }
    if (RCLASS_ORIGIN(orig) == orig) {
        RCLASS_SET_SUPER(clone, RCLASS_SUPER(orig));
    }
    else {
        VALUE p = RCLASS_SUPER(orig);
        VALUE orig_origin = RCLASS_ORIGIN(orig);
        VALUE prev_clone_p = clone;
        VALUE origin_stack = rb_ary_tmp_new(2);
        VALUE origin[2];
        VALUE clone_p = 0;
        long origin_len;
        int add_subclass;
        VALUE clone_origin;
        ensure_origin(clone);
        clone_origin = RCLASS_ORIGIN(clone);
        while (p && p != orig_origin) {
            if (BUILTIN_TYPE(p) != T_ICLASS) {
                rb_bug("non iclass between module/class and origin");
            }
            clone_p = class_alloc(RBASIC(p)->flags, RBASIC(p)->klass);
            RCLASS_SET_SUPER(prev_clone_p, clone_p);
            prev_clone_p = clone_p;
            RCLASS_M_TBL(clone_p) = RCLASS_M_TBL(p);
            RCLASS_CONST_TBL(clone_p) = RCLASS_CONST_TBL(p);
            RCLASS_IV_TBL(clone_p) = RCLASS_IV_TBL(p);
            RCLASS_EXT(clone_p)->allocator = RCLASS_EXT(p)->allocator;
            if (RB_TYPE_P(clone, T_CLASS)) {
                RCLASS_SET_INCLUDER(clone_p, clone);
            }
            add_subclass = TRUE;
            if (p != RCLASS_ORIGIN(p)) {
                origin[0] = clone_p;
                origin[1] = RCLASS_ORIGIN(p);
                rb_ary_cat(origin_stack, origin, 2);
            }
            else if ((origin_len = RARRAY_LEN(origin_stack)) > 1 &&
                     RARRAY_AREF(origin_stack, origin_len - 1) == p) {
                RCLASS_SET_ORIGIN(RARRAY_AREF(origin_stack, (origin_len -= 2)), clone_p);
                RICLASS_SET_ORIGIN_SHARED_MTBL(clone_p);
                rb_ary_resize(origin_stack, origin_len);
                add_subclass = FALSE;
            }
            if (add_subclass) {
                rb_module_add_to_subclasses_list(RBASIC(p)->klass, clone_p);
            }
            p = RCLASS_SUPER(p);
        }
        if (p == orig_origin) {
            if (clone_p) {
                RCLASS_SET_SUPER(clone_p, clone_origin);
                RCLASS_SET_SUPER(clone_origin, RCLASS_SUPER(orig_origin));
            }
            copy_tables(clone_origin, orig_origin);
            if (RCLASS_M_TBL(orig_origin)) {
                struct clone_method_arg arg;
                arg.old_klass = orig;
                arg.new_klass = clone;
                RCLASS_M_TBL_INIT(clone_origin);
                rb_id_table_foreach(RCLASS_M_TBL(orig_origin), clone_method_i, &arg);
            }
        }
        else {
            rb_bug("no origin for class that has origin");
        }
    }
    return clone;
}
  Alias for #to_s.
    #instance_method(symbol)  ⇒ unbound_method   
Returns an ::UnboundMethod representing the given instance method in mod.
class Interpreter
  def do_a() print "there, "; end
  def do_d() print "Hello ";  end
  def do_e() print "!\n";     end
  def do_v() print "Dave";    end
  Dispatcher = {
    "a" => instance_method(:do_a),
    "d" => instance_method(:do_d),
    "e" => instance_method(:do_e),
    "v" => instance_method(:do_v)
  }
  def interpret(string)
    string.each_char {|b| Dispatcher[b].bind(self).call }
  end
end
interpreter = Interpreter.new
interpreter.interpret('dave')produces:
Hello there, Dave!# File 'proc.c', line 2103
static VALUE
rb_mod_instance_method(VALUE mod, VALUE vid)
{
    ID id = rb_check_id(&vid);
    if (!id) {
	rb_method_name_error(mod, vid);
    }
    return mnew(mod, Qundef, id, rb_cUnboundMethod, FALSE);
}
  #instance_methods(include_super = true) ⇒ Array
Returns an array containing the names of the public and protected instance methods in the receiver. For a module, these are the public and protected methods; for a class, they are the instance (not singleton) methods. If the optional parameter is false, the methods of any ancestors are not included.
module A
  def method1()  end
end
class B
  include A
  def method2()  end
end
class C < B
  def method3()  end
end
A.instance_methods(false)                   #=> [:method1]
B.instance_methods(false)                   #=> [:method2]
B.instance_methods(true).include?(:method1) #=> true
C.instance_methods(false)                   #=> [:method3]
C.instance_methods.include?(:method2)       #=> true# File 'class.c', line 1473
VALUE
rb_class_instance_methods(int argc, const VALUE *argv, VALUE mod)
{
    return class_instance_method_list(argc, argv, mod, 0, ins_methods_i);
}
  
    
      #extended(symbol)   (private)
      #method_added(symbol)  
    
  
    
      #method_defined?(symbol, inherit = true)  ⇒ Boolean 
      #method_defined?(string, inherit = true)  ⇒ Boolean 
    
  
Boolean 
      #method_defined?(string, inherit = true)  ⇒ Boolean 
    Returns true if the named method is defined by mod.  If inherit is set, the lookup will also search mod’s ancestors. Public and protected methods are matched. ::String arguments are converted to symbols.
module A
  def method1()  end
  def protected_method1()  end
  protected :protected_method1
end
class B
  def method2()  end
  def private_method2()  end
  private :private_method2
end
class C < B
  include A
  def method3()  end
end
A.method_defined? :method1              #=> true
C.method_defined? "method1"             #=> true
C.method_defined? "method2"             #=> true
C.method_defined? "method2", true       #=> true
C.method_defined? "method2", false      #=> false
C.method_defined? "method3"             #=> true
C.method_defined? "protected_method1"   #=> true
C.method_defined? "method4"             #=> false
C.method_defined? "private_method2"     #=> false# File 'vm_method.c', line 1699
static VALUE
rb_mod_method_defined(int argc, VALUE *argv, VALUE mod)
{
    rb_method_visibility_t visi = check_definition_visibility(mod, argc, argv);
    return (visi == METHOD_VISI_PUBLIC || visi == METHOD_VISI_PROTECTED) ? Qtrue : Qfalse;
}
  
    
      #extended(symbol)   (private)
      #method_removed(symbol)  
    
  
Alias for #extended. Invoked as a callback whenever an instance method is removed from the receiver.
module Chatty
  def self.method_removed(method_name)
    puts "Removing #{method_name.inspect}"
  end
  def self.some_class_method() end
  def some_instance_method() end
  class << self
    remove_method :some_class_method
  end
  remove_method :some_instance_method
endproduces:
Removing :some_instance_method
    
      #extended(symbol)   (private)
      #method_undefined(symbol)  
    
  
Alias for #extended.
Alias for #class_eval.
Alias for #class_exec.
    
      #module_function(symbol, ...)  ⇒ self  (private)
      #module_function(string, ...)  ⇒ self 
    
  
self  (private)
      #module_function(string, ...)  ⇒ self 
    Creates module functions for the named methods. These functions may be called with the module as a receiver, and also become available as instance methods to classes that mix in the module. Module functions are copies of the original, and so may be changed independently. The instance-method versions are made private. If used with no arguments, subsequently defined methods become module functions. ::String arguments are converted to symbols.
module Mod
  def one
    "This is one"
  end
  module_function :one
end
class Cls
  include Mod
  def call_one
    one
  end
end
Mod.one     #=> "This is one"
c = Cls.new
c.call_one  #=> "This is one"
module Mod
  def one
    "This is the new one"
  end
end
Mod.one     #=> "This is one"
c.call_one  #=> "This is the new one"# File 'vm_method.c', line 2392
static VALUE
rb_mod_modfunc(int argc, VALUE *argv, VALUE module)
{
    int i;
    ID id;
    const rb_method_entry_t *me;
    if (!RB_TYPE_P(module, T_MODULE)) {
	rb_raise(rb_eTypeError, "module_function must be called for modules");
    }
    if (argc == 0) {
	rb_scope_module_func_set();
	return module;
    }
    set_method_visibility(module, argc, argv, METHOD_VISI_PRIVATE);
    for (i = 0; i < argc; i++) {
	VALUE m = module;
	id = rb_to_id(argv[i]);
	for (;;) {
	    me = search_method(m, id, 0);
	    if (me == 0) {
		me = search_method(rb_cObject, id, 0);
	    }
	    if (UNDEFINED_METHOD_ENTRY_P(me)) {
		rb_print_undef(module, id, METHOD_VISI_UNDEF);
	    }
	    if (me->def->type != VM_METHOD_TYPE_ZSUPER) {
		break; /* normal case: need not to follow 'super' link */
	    }
	    m = RCLASS_SUPER(m);
	    if (!m)
		break;
	}
	rb_method_entry_set(rb_singleton_class(module), id, me, METHOD_VISI_PUBLIC);
    }
    return module;
}
  #name ⇒ String
Returns the name of the module mod. Returns nil for anonymous modules.
# File 'variable.c', line 117
VALUE
rb_mod_name(VALUE mod)
{
    int permanent;
    return classname(mod, &permanent);
}
  
    #prepend(module, ...)  ⇒ self   
Invokes #prepend_features on each parameter in reverse order.
# File 'eval.c', line 1363
static VALUE
rb_mod_prepend(int argc, VALUE *argv, VALUE module)
{
    int i;
    ID id_prepend_features, id_prepended;
    CONST_ID(id_prepend_features, "prepend_features");
    CONST_ID(id_prepended, "prepended");
    rb_check_arity(argc, 1, UNLIMITED_ARGUMENTS);
    for (i = 0; i < argc; i++)
	Check_Type(argv[i], T_MODULE);
    while (argc--) {
	rb_funcall(argv[argc], id_prepend_features, 1, module);
	rb_funcall(argv[argc], id_prepended, 1, module);
    }
    return module;
}
  
    #prepend_features(mod)  ⇒ mod  (private)  
When this module is prepended in another, Ruby calls #prepend_features in this module, passing it the receiving module in mod. Ruby’s default implementation is to overlay the constants, methods, and module variables of this module to mod if this module has not already been added to mod or one of its ancestors. See also #prepend.
# File 'eval.c', line 1345
static VALUE
rb_mod_prepend_features(VALUE module, VALUE prepend)
{
    if (!CLASS_OR_MODULE_P(prepend)) {
	Check_Type(prepend, T_CLASS);
    }
    rb_prepend_module(prepend, module);
    return module;
}
  
    
      #extended(symbol)   (private)
      #prepended(symbol)  
    
  
Alias for #extended. The equivalent of #included, but for prepended modules.
module A
  def self.prepended(mod)
    puts "#{self} prepended to #{mod}"
  end
end
module Enumerable
  prepend A
end
 # => prints "A prepended to Enumerable"
    
      #private  ⇒ self  (private)
      #private(symbol, ...)  ⇒ self 
      #private(string, ...)  ⇒ self 
      #private(array)  ⇒ self 
    
  
self  (private)
      #private(symbol, ...)  ⇒ self 
      #private(string, ...)  ⇒ self 
      #private(array)  ⇒ self 
    With no arguments, sets the default visibility for subsequently defined methods to private. With arguments, sets the named methods to have private visibility. ::String arguments are converted to symbols. An Array of Symbols and/or Strings are also accepted.
module Mod
  def a()  end
  def b()  end
  private
  def c()  end
  private :a
end
Mod.private_instance_methods   #=> [:a, :c]Note that to show a private method on RDoc, use :doc:.
# File 'vm_method.c', line 2138
static VALUE
rb_mod_private(int argc, VALUE *argv, VALUE module)
{
    return set_visibility(argc, argv, module, METHOD_VISI_PRIVATE);
}
  
    
      #private_class_method(symbol, ...)  ⇒ mod 
      #private_class_method(string, ...)  ⇒ mod 
      #private_class_method(array)  ⇒ mod 
    
  
mod 
      #private_class_method(string, ...)  ⇒ mod 
      #private_class_method(array)  ⇒ mod 
    Makes existing class methods private. Often used to hide the default constructor .new.
::String arguments are converted to symbols. An Array of Symbols and/or Strings are also accepted.
class SimpleSingleton  # Not thread safe
  private_class_method :new
  def SimpleSingleton.create(*args, &block)
    @me = new(*args, &block) if ! @me
    @me
  end
end# File 'vm_method.c', line 2293
static VALUE
rb_mod_private_method(int argc, VALUE *argv, VALUE obj)
{
    set_method_visibility(rb_singleton_class(obj), argc, argv, METHOD_VISI_PRIVATE);
    return obj;
}
  
    #private_constant(symbol, ...)  ⇒ mod   
Makes a list of existing constants private.
# File 'variable.c', line 3240
VALUE
rb_mod_private_constant(int argc, const VALUE *argv, VALUE obj)
{
    set_const_visibility(obj, argc, argv, CONST_PRIVATE, CONST_VISIBILITY_MASK);
    return obj;
}
  #private_instance_methods(include_super = true) ⇒ Array
Returns a list of the private instance methods defined in mod. If the optional parameter is false, the methods of any ancestors are not included.
module Mod
  def method1()  end
  private :method1
  def method2()  end
end
Mod.instance_methods           #=> [:method2]
Mod.private_instance_methods   #=> [:method1]# File 'class.c', line 1511
VALUE
rb_class_private_instance_methods(int argc, const VALUE *argv, VALUE mod)
{
    return class_instance_method_list(argc, argv, mod, 0, ins_methods_priv_i);
}
  
    
      #private_method_defined?(symbol, inherit = true)  ⇒ Boolean 
      #private_method_defined?(string, inherit = true)  ⇒ Boolean 
    
  
Boolean 
      #private_method_defined?(string, inherit = true)  ⇒ Boolean 
    Returns true if the named private method is defined by mod.  If inherit is set, the lookup will also search mod’s ancestors. ::String arguments are converted to symbols.
module A
  def method1()  end
end
class B
  private
  def method2()  end
end
class C < B
  include A
  def method3()  end
end
A.method_defined? :method1                   #=> true
C.private_method_defined? "method1"          #=> false
C.private_method_defined? "method2"          #=> true
C.private_method_defined? "method2", true    #=> true
C.private_method_defined? "method2", false   #=> false
C.method_defined? "method2"                  #=> false# File 'vm_method.c', line 1778
static VALUE
rb_mod_private_method_defined(int argc, VALUE *argv, VALUE mod)
{
    return check_definition(mod, argc, argv, METHOD_VISI_PRIVATE);
}
  
    
      #protected  ⇒ self  (private)
      #protected(symbol, ...)  ⇒ self 
      #protected(string, ...)  ⇒ self 
      #protected(array)  ⇒ self 
    
  
self  (private)
      #protected(symbol, ...)  ⇒ self 
      #protected(string, ...)  ⇒ self 
      #protected(array)  ⇒ self 
    With no arguments, sets the default visibility for subsequently defined methods to protected. With arguments, sets the named methods to have protected visibility. ::String arguments are converted to symbols. An Array of Symbols and/or Strings are also accepted.
If a method has protected visibility, it is callable only where self of the context is the same as the method. (method definition or instance_eval). This behavior is different from Java’s protected method. Usually #private should be used.
Note that a protected method is slow because it can’t use inline cache.
To show a private method on RDoc, use :doc: instead of this.
# File 'vm_method.c', line 2107
static VALUE
rb_mod_protected(int argc, VALUE *argv, VALUE module)
{
    return set_visibility(argc, argv, module, METHOD_VISI_PROTECTED);
}
  #protected_instance_methods(include_super = true) ⇒ Array
Returns a list of the protected instance methods defined in mod. If the optional parameter is false, the methods of any ancestors are not included.
# File 'class.c', line 1488
VALUE
rb_class_protected_instance_methods(int argc, const VALUE *argv, VALUE mod)
{
    return class_instance_method_list(argc, argv, mod, 0, ins_methods_prot_i);
}
  
    
      #protected_method_defined?(symbol, inherit = true)  ⇒ Boolean 
      #protected_method_defined?(string, inherit = true)  ⇒ Boolean 
    
  
Boolean 
      #protected_method_defined?(string, inherit = true)  ⇒ Boolean 
    Returns true if the named protected method is defined mod.  If inherit is set, the lookup will also search mod’s ancestors. ::String arguments are converted to symbols.
module A
  def method1()  end
end
class B
  protected
  def method2()  end
end
class C < B
  include A
  def method3()  end
end
A.method_defined? :method1                    #=> true
C.protected_method_defined? "method1"         #=> false
C.protected_method_defined? "method2"         #=> true
C.protected_method_defined? "method2", true   #=> true
C.protected_method_defined? "method2", false  #=> false
C.method_defined? "method2"                   #=> true# File 'vm_method.c', line 1814
static VALUE
rb_mod_protected_method_defined(int argc, VALUE *argv, VALUE mod)
{
    return check_definition(mod, argc, argv, METHOD_VISI_PROTECTED);
}
  
    
      #public  ⇒ self  (private)
      #public(symbol, ...)  ⇒ self 
      #public(string, ...)  ⇒ self 
      #public(array)  ⇒ self 
    
  
self  (private)
      #public(symbol, ...)  ⇒ self 
      #public(string, ...)  ⇒ self 
      #public(array)  ⇒ self 
    With no arguments, sets the default visibility for subsequently defined methods to public. With arguments, sets the named methods to have public visibility. ::String arguments are converted to symbols. An Array of Symbols and/or Strings are also accepted.
# File 'vm_method.c', line 2078
static VALUE
rb_mod_public(int argc, VALUE *argv, VALUE module)
{
    return set_visibility(argc, argv, module, METHOD_VISI_PUBLIC);
}
  
    
      #public_class_method(symbol, ...)  ⇒ mod 
      #public_class_method(string, ...)  ⇒ mod 
      #public_class_method(array)  ⇒ mod 
    
  
mod 
      #public_class_method(string, ...)  ⇒ mod 
      #public_class_method(array)  ⇒ mod 
    Makes a list of existing class methods public.
::String arguments are converted to symbols. An Array of Symbols and/or Strings are also accepted.
# File 'vm_method.c', line 2265
static VALUE
rb_mod_public_method(int argc, VALUE *argv, VALUE obj)
{
    set_method_visibility(rb_singleton_class(obj), argc, argv, METHOD_VISI_PUBLIC);
    return obj;
}
  
    #public_constant(symbol, ...)  ⇒ mod   
Makes a list of existing constants public.
# File 'variable.c', line 3254
VALUE
rb_mod_public_constant(int argc, const VALUE *argv, VALUE obj)
{
    set_const_visibility(obj, argc, argv, CONST_PUBLIC, CONST_VISIBILITY_MASK);
    return obj;
}
  
    #public_instance_method(symbol)  ⇒ unbound_method   
Similar to instance_method, searches public method only.
# File 'proc.c', line 2120
static VALUE
rb_mod_public_instance_method(VALUE mod, VALUE vid)
{
    ID id = rb_check_id(&vid);
    if (!id) {
	rb_method_name_error(mod, vid);
    }
    return mnew(mod, Qundef, id, rb_cUnboundMethod, TRUE);
}
  #public_instance_methods(include_super = true) ⇒ Array
Returns a list of the public instance methods defined in mod. If the optional parameter is false, the methods of any ancestors are not included.
# File 'class.c', line 1526
VALUE
rb_class_public_instance_methods(int argc, const VALUE *argv, VALUE mod)
{
    return class_instance_method_list(argc, argv, mod, 0, ins_methods_pub_i);
}
  
    
      #public_method_defined?(symbol, inherit = true)  ⇒ Boolean 
      #public_method_defined?(string, inherit = true)  ⇒ Boolean 
    
  
Boolean 
      #public_method_defined?(string, inherit = true)  ⇒ Boolean 
    Returns true if the named public method is defined by mod.  If inherit is set, the lookup will also search mod’s ancestors. ::String arguments are converted to symbols.
module A
  def method1()  end
end
class B
  protected
  def method2()  end
end
class C < B
  include A
  def method3()  end
end
A.method_defined? :method1                 #=> true
C.public_method_defined? "method1"         #=> true
C.public_method_defined? "method1", true   #=> true
C.public_method_defined? "method1", false  #=> true
C.public_method_defined? "method2"         #=> false
C.method_defined? "method2"                #=> true# File 'vm_method.c', line 1742
static VALUE
rb_mod_public_method_defined(int argc, VALUE *argv, VALUE mod)
{
    return check_definition(mod, argc, argv, METHOD_VISI_PUBLIC);
}
  
    #refine(mod)  ⇒ Module  (private)  
Refine mod in the receiver.
Returns a module, where refined methods are defined.
# File 'eval.c', line 1560
static VALUE
rb_mod_refine(VALUE module, VALUE klass)
{
    VALUE refinement;
    ID id_refinements, id_activated_refinements,
       id_refined_class, id_defined_at;
    VALUE refinements, activated_refinements;
    rb_thread_t *th = GET_THREAD();
    VALUE block_handler = rb_vm_frame_block_handler(th->ec->cfp);
    if (block_handler == VM_BLOCK_HANDLER_NONE) {
	rb_raise(rb_eArgError, "no block given");
    }
    if (vm_block_handler_type(block_handler) != block_handler_type_iseq) {
	rb_raise(rb_eArgError, "can't pass a Proc as a block to Module#refine");
    }
    ensure_class_or_module(klass);
    CONST_ID(id_refinements, "__refinements__");
    refinements = rb_attr_get(module, id_refinements);
    if (NIL_P(refinements)) {
	refinements = hidden_identity_hash_new();
	rb_ivar_set(module, id_refinements, refinements);
    }
    CONST_ID(id_activated_refinements, "__activated_refinements__");
    activated_refinements = rb_attr_get(module, id_activated_refinements);
    if (NIL_P(activated_refinements)) {
	activated_refinements = hidden_identity_hash_new();
	rb_ivar_set(module, id_activated_refinements,
		    activated_refinements);
    }
    refinement = rb_hash_lookup(refinements, klass);
    if (NIL_P(refinement)) {
	VALUE superclass = refinement_superclass(klass);
	refinement = rb_module_new();
	RCLASS_SET_SUPER(refinement, superclass);
	FL_SET(refinement, RMODULE_IS_REFINEMENT);
	CONST_ID(id_refined_class, "__refined_class__");
	rb_ivar_set(refinement, id_refined_class, klass);
	CONST_ID(id_defined_at, "__defined_at__");
	rb_ivar_set(refinement, id_defined_at, module);
	rb_hash_aset(refinements, klass, refinement);
	add_activated_refinement(activated_refinements, klass, refinement);
    }
    rb_yield_refine_block(refinement, activated_refinements);
    return refinement;
}
  #remove_class_variable(sym) ⇒ Object
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)
endproduces:
99
nil# File 'variable.c', line 3546
VALUE
rb_mod_remove_cvar(VALUE mod, VALUE name)
{
    const ID id = id_for_var_message(mod, name, class, "wrong class variable name %1$s");
    st_data_t val, n = id;
    if (!id) {
        goto not_defined;
    }
    rb_check_frozen(mod);
    if (RCLASS_IV_TBL(mod) && st_delete(RCLASS_IV_TBL(mod), &n, &val)) {
	return (VALUE)val;
    }
    if (rb_cvar_defined(mod, id)) {
	rb_name_err_raise("cannot remove %1$s for %2$s", mod, ID2SYM(id));
    }
  not_defined:
    rb_name_err_raise("class variable %1$s not defined for %2$s",
                      mod, name);
    UNREACHABLE_RETURN(Qundef);
}
  #remove_const(sym) ⇒ Object (private)
Removes the definition of the given constant, returning that constant’s previous value. If that constant referred to a module, this will not change that module’s name and can lead to confusion.
# File 'variable.c', line 2715
VALUE
rb_mod_remove_const(VALUE mod, VALUE name)
{
    const ID id = id_for_var(mod, name, a, constant);
    if (!id) {
        undefined_constant(mod, name);
    }
    return rb_const_remove(mod, id);
}
  
    
      #remove_method(symbol)  ⇒ self 
      #remove_method(string)  ⇒ self 
    
  
self 
      #remove_method(string)  ⇒ self 
    Removes the method identified by symbol from the current class. For an example, see #undef_method. ::String arguments are converted to symbols.
# File 'vm_method.c', line 1372
static VALUE
rb_mod_remove_method(int argc, VALUE *argv, VALUE mod)
{
    int i;
    for (i = 0; i < argc; i++) {
	VALUE v = argv[i];
	ID id = rb_check_id(&v);
	if (!id) {
	    rb_name_err_raise("method `%1$s' not defined in %2$s",
			      mod, v);
	}
	remove_method(mod, id);
    }
    return mod;
}
  
    #ruby2_keywords(method_name, ...)  ⇒ nil  (private)  
For the given method names, marks the method as passing keywords through a normal argument splat.  This should only be called on methods that accept an argument splat (*args) but not explicit keywords or a keyword splat.  It marks the method such that if the method is called with keyword arguments, the final hash argument is marked with a special flag such that if it is the final element of a normal argument splat to another method call, and that method call does not include explicit keywords or a keyword splat, the final element is interpreted as keywords. In other words, keywords will be passed through the method to other methods.
This should only be used for methods that delegate keywords to another method, and only for backwards compatibility with Ruby versions before 2.7.
This method will probably be removed at some point, as it exists only for backwards compatibility. As it does not exist in Ruby versions before 2.7, check that the module responds to this method before calling it. Also, be aware that if this method is removed, the behavior of the method will change so that it does not pass through keywords.
module Mod
  def foo(meth, *args, &block)
    send(:"do_#{meth}", *args, &block)
  end
  ruby2_keywords(:foo) if respond_to?(:ruby2_keywords, true)
end# File 'vm_method.c', line 2177
static VALUE
rb_mod_ruby2_keywords(int argc, VALUE *argv, VALUE module)
{
    int i;
    VALUE origin_class = RCLASS_ORIGIN(module);
    rb_check_arity(argc, 1, UNLIMITED_ARGUMENTS);
    rb_check_frozen(module);
    for (i = 0; i < argc; i++) {
        VALUE v = argv[i];
        ID name = rb_check_id(&v);
        rb_method_entry_t *me;
        VALUE defined_class;
        if (!name) {
            rb_print_undef_str(module, v);
        }
        me = search_method(origin_class, name, &defined_class);
        if (!me && RB_TYPE_P(module, T_MODULE)) {
            me = search_method(rb_cObject, name, &defined_class);
        }
        if (UNDEFINED_METHOD_ENTRY_P(me) ||
            UNDEFINED_REFINED_METHOD_P(me->def)) {
            rb_print_undef(module, name, METHOD_VISI_UNDEF);
        }
        if (module == defined_class || origin_class == defined_class) {
            switch (me->def->type) {
              case VM_METHOD_TYPE_ISEQ:
                if (me->def->body.iseq.iseqptr->body->param.flags.has_rest &&
                        !me->def->body.iseq.iseqptr->body->param.flags.has_kw &&
                        !me->def->body.iseq.iseqptr->body->param.flags.has_kwrest) {
                    me->def->body.iseq.iseqptr->body->param.flags.ruby2_keywords = 1;
                    rb_clear_method_cache(module, name);
                }
                else {
                    rb_warn("Skipping set of ruby2_keywords flag for %s (method accepts keywords or method does not accept argument splat)", rb_id2name(name));
                }
                break;
              case VM_METHOD_TYPE_BMETHOD: {
                VALUE procval = me->def->body.bmethod.proc;
                if (vm_block_handler_type(procval) == block_handler_type_proc) {
                    procval = vm_proc_to_block_handler(VM_BH_TO_PROC(procval));
                }
                if (vm_block_handler_type(procval) == block_handler_type_iseq) {
                    const struct rb_captured_block *captured = VM_BH_TO_ISEQ_BLOCK(procval);
                    const rb_iseq_t *iseq = rb_iseq_check(captured->code.iseq);
                    if (iseq->body->param.flags.has_rest &&
                            !iseq->body->param.flags.has_kw &&
                            !iseq->body->param.flags.has_kwrest) {
                        iseq->body->param.flags.ruby2_keywords = 1;
                        rb_clear_method_cache(module, name);
                    }
                    else {
                        rb_warn("Skipping set of ruby2_keywords flag for %s (method accepts keywords or method does not accept argument splat)", rb_id2name(name));
                    }
                    break;
                }
              }
              /* fallthrough */
              default:
                rb_warn("Skipping set of ruby2_keywords flag for %s (method not defined in Ruby)", rb_id2name(name));
                break;
            }
        }
        else {
            rb_warn("Skipping set of ruby2_keywords flag for %s (can only set in method defining module)", rb_id2name(name));
        }
    }
    return Qnil;
}
  #to_s ⇒ String Also known as: #inspect
Returns a string representing this module or class. For basic classes and modules, this is the name. For singletons, we show information on the thing we’re attached to as well.
# File 'object.c', line 1677
static VALUE
rb_mod_to_s(VALUE klass)
{
    ID id_defined_at;
    VALUE refined_class, defined_at;
    if (FL_TEST(klass, FL_SINGLETON)) {
	VALUE s = rb_usascii_str_new2("#<Class:");
	VALUE v = rb_ivar_get(klass, id__attached__);
	if (CLASS_OR_MODULE_P(v)) {
	    rb_str_append(s, rb_inspect(v));
	}
	else {
	    rb_str_append(s, rb_any_to_s(v));
	}
	rb_str_cat2(s, ">");
	return s;
    }
    refined_class = rb_refinement_module_get_refined_class(klass);
    if (!NIL_P(refined_class)) {
	VALUE s = rb_usascii_str_new2("#<refinement:");
	rb_str_concat(s, rb_inspect(refined_class));
	rb_str_cat2(s, "@");
	CONST_ID(id_defined_at, "__defined_at__");
	defined_at = rb_attr_get(klass, id_defined_at);
	rb_str_concat(s, rb_inspect(defined_at));
	rb_str_cat2(s, ">");
	return s;
    }
    return rb_class_name(klass);
}
  
    
      #undef_method(symbol)  ⇒ self 
      #undef_method(string)  ⇒ self 
    
  
self 
      #undef_method(string)  ⇒ self 
    Prevents the current class from responding to calls to the named method. Contrast this with #remove_method, which deletes the method from the particular class; Ruby will still search superclasses and mixed-in modules for a possible receiver. ::String arguments are converted to symbols.
class Parent
  def hello
    puts "In parent"
  end
end
class Child < Parent
  def hello
    puts "In child"
  end
end
c = Child.new
c.hello
class Child
  remove_method :hello  # remove from child, still in parent
end
c.hello
class Child
  undef_method :hello   # prevent any calls to 'hello'
end
c.helloproduces:
In child
In parent
prog.rb:23: undefined method `hello' for #<Child:0x401b3bb4> (NoMethodError)# File 'vm_method.c', line 1617
static VALUE
rb_mod_undef_method(int argc, VALUE *argv, VALUE mod)
{
    int i;
    for (i = 0; i < argc; i++) {
	VALUE v = argv[i];
	ID id = rb_check_id(&v);
	if (!id) {
	    rb_method_name_error(mod, v);
	}
	rb_undef(mod, id);
    }
    return mod;
}
  
    #using(module)  ⇒ self  (private)  
Import class refinements from module into the current class or module definition.
# File 'eval.c', line 1627
static VALUE
mod_using(VALUE self, VALUE module)
{
    rb_control_frame_t *prev_cfp = previous_frame(GET_EC());
    if (prev_frame_func()) {
	rb_raise(rb_eRuntimeError,
		 "Module#using is not permitted in methods");
    }
    if (prev_cfp && prev_cfp->self != self) {
	rb_raise(rb_eRuntimeError, "Module#using is not called on self");
    }
    if (rb_block_given_p()) {
	ignored_block(module, "Module#");
    }
    rb_using_module(rb_vm_cref_replace_with_duplicated_cref(), module);
    return self;
}