Class: Object
Overview
Object is the default root of all Ruby objects. Object inherits from BasicObject which allows creating alternate object hierarchies. Methods on Object are available to all classes unless explicitly overridden.
Object mixes in the Kernel module, making the built-in kernel functions globally accessible. Although the instance methods of Object are defined by the Kernel module, we have chosen to document them here for clarity.
When referencing constants in classes inheriting from Object you do not need to use the full namespace. For example, referencing File
inside YourClass
will find the top-level File class.
In the descriptions of Object’s methods, the parameter symbol refers to a symbol, which is either a quoted string or a Symbol (such as :name
).
Constant Summary collapse
- Bignum =
An obsolete class, use Integer
rb_cInteger
- Fixnum =
An obsolete class, use Integer
rb_cInteger
Instance Method Summary collapse
-
#!~(other) ⇒ Boolean
Returns true if two objects do not match (using the =~ method), otherwise false.
-
#<=>(other) ⇒ 0?
Returns 0 if
obj
andother
are the same object orobj == other
, otherwise nil. - #=== ⇒ Object
-
#=~(other) ⇒ nil
This method is deprecated.
-
#define_singleton_method(*args) ⇒ Object
Defines a singleton method in the receiver.
-
#display(port = $>) ⇒ nil
Prints obj on the given port (default
$>
). -
#dup ⇒ Object
Produces a shallow copy of obj—the instance variables of obj are copied, but not the objects they reference.
-
#enum_for(*args) ⇒ Object
Creates a new Enumerator which will enumerate by calling
method
onobj
, passingargs
if any. -
#eql?(obj2) ⇒ Object
Equality — At the Object level, #== returns
true
only ifobj
andother
are the same object. -
#extend ⇒ Object
Adds to obj the instance methods from each module given as a parameter.
-
#freeze ⇒ Object
Prevents further modifications to obj.
- #hash ⇒ Object
-
#initialize_clone(*args) ⇒ Object
! :nodoc:.
-
#initialize_copy(orig) ⇒ Object
:nodoc:.
-
#initialize_dup(orig) ⇒ Object
! :nodoc:.
-
#inspect ⇒ String
Returns a string containing a human-readable representation of obj.
-
#instance_of? ⇒ Boolean
Returns
true
if obj is an instance of the given class. -
#instance_variable_defined?(iv) ⇒ Object
Returns
true
if the given instance variable is defined in obj. -
#instance_variable_get(iv) ⇒ Object
Returns the value of the given instance variable, or nil if the instance variable is not set.
-
#instance_variable_set(iv, val) ⇒ Object
Sets the instance variable named by symbol to the given object.
-
#instance_variables ⇒ Array
Returns an array of instance variable names for the receiver.
-
#is_a?(c) ⇒ Object
Returns
true
if class is the class of obj, or if class is one of the superclasses of obj or modules included in obj. -
#itself ⇒ Object
Returns the receiver.
-
#kind_of?(c) ⇒ Object
Returns
true
if class is the class of obj, or if class is one of the superclasses of obj or modules included in obj. -
#method(sym) ⇒ Object
Looks up the named method as a receiver in obj, returning a Method object (or raising NameError).
-
#methods(regular = true) ⇒ Array
Returns a list of the names of public and protected methods of obj.
-
#nil? ⇒ Boolean
Only the object nil responds
true
tonil?
. -
#object_id ⇒ Object
call-seq: obj.__id__ -> integer obj.object_id -> integer.
-
#private_methods(all = true) ⇒ Array
Returns the list of private methods accessible to obj.
-
#protected_methods(all = true) ⇒ Array
Returns the list of protected methods accessible to obj.
-
#public_method(sym) ⇒ Object
Similar to method, searches public method only.
-
#public_methods(all = true) ⇒ Array
Returns the list of public methods accessible to obj.
-
#public_send(*args) ⇒ Object
Invokes the method identified by symbol, passing it any arguments specified.
-
#remove_instance_variable(name) ⇒ Object
Removes the named instance variable from obj, returning that variable’s value.
-
#respond_to?(*args) ⇒ Object
Returns
true
if obj responds to the given method. -
#respond_to_missing?(mid, priv) ⇒ Object
DO NOT USE THIS DIRECTLY.
-
#send(*args) ⇒ Object
Invokes the method identified by symbol, passing it any arguments specified.
-
#singleton_class ⇒ Class
Returns the singleton class of obj.
-
#singleton_method(sym) ⇒ Object
Similar to method, searches singleton method only.
-
#singleton_methods(all = true) ⇒ Array
Returns an array of the names of singleton methods for obj.
-
#taint ⇒ Object
Returns object.
-
#tainted? ⇒ false
Returns false.
-
#to_enum(*args) ⇒ Object
Creates a new Enumerator which will enumerate by calling
method
onobj
, passingargs
if any. -
#to_s ⇒ String
Returns a string representing obj.
-
#trust ⇒ Object
Returns object.
-
#untaint ⇒ Object
Returns object.
-
#untrust ⇒ Object
Returns object.
-
#untrusted? ⇒ false
Returns false.
Methods included from Kernel
#Array, #Complex, #Hash, #Integer, #Rational, #String, #__callee__, #__dir__, #__method__, #`, #abort, #at_exit, #autoload, #autoload?, #binding, #block_given?, #callcc, #caller, #caller_locations, #catch, #eval, #exec, #exit, #exit!, #fail, #fork, #format, #gets, #global_variables, #iterator?, #lambda, #load, #local_variables, #loop, #open, #p, #print, #printf, #proc, #putc, #puts, #raise, #rand, #readline, #readlines, #require, #require_relative, #select, #set_trace_func, #sleep, #spawn, #sprintf, #srand, #syscall, #system, #test, #throw, #trace_var, #trap, #untrace_var
Instance Method Details
#!~(other) ⇒ Boolean
Returns true if two objects do not match (using the =~ method), otherwise false.
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# File 'object.c', line 1606
static VALUE
rb_obj_not_match(VALUE obj1, VALUE obj2)
{
VALUE result = rb_funcall(obj1, id_match, 1, obj2);
return RTEST(result) ? Qfalse : Qtrue;
}
|
#<=>(other) ⇒ 0?
Returns 0 if obj
and other
are the same object or obj == other
, otherwise nil.
The #<=> is used by various methods to compare objects, for example Enumerable#sort, Enumerable#max etc.
Your implementation of #<=> should return one of the following values: -1, 0, 1 or nil. -1 means self is smaller than other. 0 means self is equal to other. 1 means self is bigger than other. Nil means the two values could not be compared.
When you define #<=>, you can include Comparable to gain the methods #<=, #<, #==, #>=, #> and #between?.
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# File 'object.c', line 1632
static VALUE
rb_obj_cmp(VALUE obj1, VALUE obj2)
{
if (rb_equal(obj1, obj2))
return INT2FIX(0);
return Qnil;
}
|
#=== ⇒ Object
#=~(other) ⇒ nil
This method is deprecated.
This is not only useless but also troublesome because it may hide a type error.
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# File 'object.c', line 1588
static VALUE
rb_obj_match(VALUE obj1, VALUE obj2)
{
if (rb_warning_category_enabled_p(RB_WARN_CATEGORY_DEPRECATED)) {
rb_category_warn(RB_WARN_CATEGORY_DEPRECATED, "deprecated Object#=~ is called on %"PRIsVALUE
"; it always returns nil", rb_obj_class(obj1));
}
return Qnil;
}
|
#define_singleton_method(symbol, method) ⇒ Object #define_singleton_method(symbol) { ... } ⇒ Object
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. 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!"
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# File 'proc.c', line 2276
static VALUE
rb_obj_define_method(int argc, VALUE *argv, VALUE obj)
{
VALUE klass = rb_singleton_class(obj);
return rb_mod_define_method(argc, argv, klass);
}
|
#display(port = $>) ⇒ nil
Prints obj on the given port (default $>
). Equivalent to:
def display(port=$>)
port.write self
nil
end
For example:
1.display
"cat".display
[ 4, 5, 6 ].display
puts
produces:
1cat[4, 5, 6]
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# File 'io.c', line 8028
static VALUE
rb_obj_display(int argc, VALUE *argv, VALUE self)
{
VALUE out;
out = (!rb_check_arity(argc, 0, 1) ? rb_ractor_stdout() : argv[0]);
rb_io_write(out, self);
return Qnil;
}
|
#dup ⇒ Object
Produces a shallow copy of obj—the instance variables of obj are copied, but not the objects they reference.
This method may have class-specific behavior. If so, that behavior will be documented under the #initialize_copy
method of the class.
on dup vs clone
In general, #clone and #dup may have different semantics in descendant classes. While #clone is used to duplicate an object, including its internal state, #dup typically uses the class of the descendant object to create the new instance.
When using #dup, any modules that the object has been extended with will not be copied.
class Klass
attr_accessor :str
end
module Foo
def foo; 'foo'; end
end
s1 = Klass.new #=> #<Klass:0x401b3a38> s1.extend(Foo) #=> #<Klass:0x401b3a38> s1.foo #=> “foo”
s2 = s1.clone #=> #<Klass:0x401be280> s2.foo #=> “foo”
s3 = s1.dup #=> #<Klass:0x401c1084> s3.foo #=> NoMethodError: undefined method ‘foo’ for #<Klass:0x401c1084>
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# File 'object.c', line 558
VALUE
rb_obj_dup(VALUE obj)
{
VALUE dup;
if (special_object_p(obj)) {
return obj;
}
dup = rb_obj_alloc(rb_obj_class(obj));
init_copy(dup, obj);
rb_funcall(dup, id_init_dup, 1, obj);
return dup;
}
|
#to_enum(method = :each, *args) ⇒ Enumerator #enum_for(method = :each, *args) ⇒ Enumerator #to_enum(method = :each, *args) {|*args| ... } ⇒ Enumerator #enum_for(method = :each, *args) {|*args| ... } ⇒ Enumerator
Creates a new Enumerator which will enumerate by calling method
on obj
, passing args
if any. What was yielded by method becomes values of enumerator.
If a block is given, it will be used to calculate the size of the enumerator without the need to iterate it (see Enumerator#size).
Examples
str = "xyz"
enum = str.enum_for(:each_byte)
enum.each { |b| puts b }
# => 120
# => 121
# => 122
# protect an array from being modified by some_method
a = [1, 2, 3]
some_method(a.to_enum)
# String#split in block form is more memory-effective:
very_large_string.split("|") { |chunk| return chunk if chunk.include?('DATE') }
# This could be rewritten more idiomatically with to_enum:
very_large_string.to_enum(:split, "|").lazy.grep(/DATE/).first
It is typical to call to_enum when defining methods for a generic Enumerable, in case no block is passed.
Here is such an example, with parameter passing and a sizing block:
module Enumerable
# a generic method to repeat the values of any enumerable
def repeat(n)
raise ArgumentError, "#{n} is negative!" if n < 0
unless block_given?
return to_enum(__method__, n) do # __method__ is :repeat here
sz = size # Call size and multiply by n...
sz * n if sz # but return nil if size itself is nil
end
end
each do |*val|
n.times { yield *val }
end
end
end
%i[hello world].repeat(2) { |w| puts w }
# => Prints 'hello', 'hello', 'world', 'world'
enum = (1..14).repeat(3)
# => returns an Enumerator when called without a block
enum.first(4) # => [1, 1, 1, 2]
enum.size # => 42
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# File 'enumerator.c', line 368
static VALUE
obj_to_enum(int argc, VALUE *argv, VALUE obj)
{
VALUE enumerator, meth = sym_each;
if (argc > 0) {
--argc;
meth = *argv++;
}
enumerator = rb_enumeratorize_with_size(obj, meth, argc, argv, 0);
if (rb_block_given_p()) {
enumerator_ptr(enumerator)->size = rb_block_proc();
}
return enumerator;
}
|
#==(other) ⇒ Boolean #equal?(other) ⇒ Boolean #eql?(other) ⇒ Boolean
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 #=> true
The #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
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# File 'object.c', line 234
MJIT_FUNC_EXPORTED VALUE
rb_obj_equal(VALUE obj1, VALUE obj2)
{
if (obj1 == obj2) return Qtrue;
return Qfalse;
}
|
#extend ⇒ Object
Adds to obj the instance methods from each module given as a parameter.
module Mod
def hello
"Hello from Mod.\n"
end
end
class Klass
def hello
"Hello from Klass.\n"
end
end
k = Klass.new
k.hello #=> "Hello from Klass.\n"
k.extend(Mod) #=> #<Klass:0x401b3bc8>
k.hello #=> "Hello from Mod.\n"
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# File 'eval.c', line 1790
static VALUE
rb_obj_extend(int argc, VALUE *argv, VALUE obj)
{
int i;
ID id_extend_object, id_extended;
CONST_ID(id_extend_object, "extend_object");
CONST_ID(id_extended, "extended");
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_extend_object, 1, obj);
rb_funcall(argv[argc], id_extended, 1, obj);
}
return obj;
}
|
#freeze ⇒ Object
Prevents further modifications to obj. A RuntimeError will be raised if modification is attempted. There is no way to unfreeze a frozen object. See also Object#frozen?.
This method returns self.
a = [ "a", "b", "c" ]
a.freeze
a << "z"
produces:
prog.rb:3:in `<<': can't modify frozen Array (FrozenError)
from prog.rb:3
Objects of the following classes are always frozen: Integer, Float, Symbol.
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# File 'object.c', line 1277
VALUE
rb_obj_freeze(VALUE obj)
{
if (!OBJ_FROZEN(obj)) {
OBJ_FREEZE(obj);
if (SPECIAL_CONST_P(obj)) {
rb_bug("special consts should be frozen.");
}
}
return obj;
}
|
#hash ⇒ Object
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# File 'object.c', line 241 VALUE rb_obj_hash(VALUE obj); |
#initialize_clone(*args) ⇒ Object
!
:nodoc:
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# File 'object.c', line 647
static VALUE
rb_obj_init_clone(int argc, VALUE *argv, VALUE obj)
{
VALUE orig, opts;
rb_scan_args(argc, argv, "1:", &orig, &opts);
/* Ignore a freeze keyword */
if (argc == 2) (void)freeze_opt(1, &opts);
rb_funcall(obj, id_init_copy, 1, orig);
return obj;
}
|
#initialize_copy(orig) ⇒ Object
:nodoc:
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# File 'object.c', line 610
VALUE
rb_obj_init_copy(VALUE obj, VALUE orig)
{
if (obj == orig) return obj;
rb_check_frozen(obj);
if (TYPE(obj) != TYPE(orig) || rb_obj_class(obj) != rb_obj_class(orig)) {
rb_raise(rb_eTypeError, "initialize_copy should take same class object");
}
return obj;
}
|
#initialize_dup(orig) ⇒ Object
!
:nodoc:
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# File 'object.c', line 630
VALUE
rb_obj_init_dup_clone(VALUE obj, VALUE orig)
{
rb_funcall(obj, id_init_copy, 1, orig);
return obj;
}
|
#inspect ⇒ String
Returns a string containing a human-readable representation of obj. The default #inspect shows the object’s class name, an encoding of its memory address, and a list of the instance variables and their values (by calling #inspect on each of them). User defined classes should override this method to provide a better representation of obj. When overriding this method, it should return a string whose encoding is compatible with the default external encoding.
[ 1, 2, 3..4, 'five' ].inspect #=> "[1, 2, 3..4, \"five\"]"
Time.new.inspect #=> "2008-03-08 19:43:39 +0900"
class Foo
end
Foo.new.inspect #=> "#<Foo:0x0300c868>"
class Bar
def initialize
@bar = 1
end
end
Bar.new.inspect #=> "#<Bar:0x0300c868 @bar=1>"
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# File 'object.c', line 777
static VALUE
rb_obj_inspect(VALUE obj)
{
if (rb_ivar_count(obj) > 0) {
VALUE str;
VALUE c = rb_class_name(CLASS_OF(obj));
str = rb_sprintf("-<%"PRIsVALUE":%p", c, (void*)obj);
return rb_exec_recursive(inspect_obj, obj, str);
}
else {
return rb_any_to_s(obj);
}
}
|
#instance_of? ⇒ Boolean
Returns true
if obj is an instance of the given class. See also Object#kind_of?.
class A; end
class B < A; end
class C < B; end
b = B.new
b.instance_of? A #=> false
b.instance_of? B #=> true
b.instance_of? C #=> false
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# File 'object.c', line 833
VALUE
rb_obj_is_instance_of(VALUE obj, VALUE c)
{
c = class_or_module_required(c);
if (rb_obj_class(obj) == c) return Qtrue;
return Qfalse;
}
|
#instance_variable_defined?(symbol) ⇒ Boolean #instance_variable_defined?(string) ⇒ Boolean
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
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# File 'object.c', line 2932
static VALUE
rb_obj_ivar_defined(VALUE obj, VALUE iv)
{
ID id = id_for_var(obj, iv, instance);
if (!id) {
return Qfalse;
}
return rb_ivar_defined(obj, id);
}
|
#instance_variable_get(symbol) ⇒ Object #instance_variable_get(string) ⇒ Object
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
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# File 'object.c', line 2870
static VALUE
rb_obj_ivar_get(VALUE obj, VALUE iv)
{
ID id = id_for_var(obj, iv, instance);
if (!id) {
return Qnil;
}
return rb_ivar_get(obj, id);
}
|
#instance_variable_set(symbol, obj) ⇒ Object #instance_variable_set(string, obj) ⇒ Object
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\">"
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# File 'object.c', line 2904
static VALUE
rb_obj_ivar_set(VALUE obj, VALUE iv, VALUE val)
{
ID id = id_for_var(obj, iv, instance);
if (!id) id = rb_intern_str(iv);
return rb_ivar_set(obj, id, val);
}
|
#instance_variables ⇒ Array
Returns an array of instance variable names for the receiver. Note that simply defining an accessor does not create the corresponding instance variable.
class Fred
attr_accessor :a1
def initialize
@iv = 3
end
end
Fred.new.instance_variables #=> [:@iv]
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# File 'variable.c', line 1800
VALUE
rb_obj_instance_variables(VALUE obj)
{
VALUE ary;
ary = rb_ary_new();
rb_ivar_foreach(obj, ivar_i, ary);
return ary;
}
|
#is_a? ⇒ Boolean #kind_of? ⇒ Boolean
Returns true
if class is the class of obj, or if class is one of the superclasses of obj or modules included in obj.
module M; end
class A
include M
end
class B < A; end
class C < B; end
b = B.new
b.is_a? A #=> true
b.is_a? B #=> true
b.is_a? C #=> false
b.is_a? M #=> true
b.kind_of? A #=> true
b.kind_of? B #=> true
b.kind_of? C #=> false
b.kind_of? M #=> true
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# File 'object.c', line 877
VALUE
rb_obj_is_kind_of(VALUE obj, VALUE c)
{
VALUE cl = CLASS_OF(obj);
c = class_or_module_required(c);
return class_search_ancestor(cl, RCLASS_ORIGIN(c)) ? Qtrue : Qfalse;
}
|
#itself ⇒ Object
Returns the receiver.
string = "my string"
string.itself.object_id == string.object_id #=> true
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# File 'object.c', line 584
static VALUE
rb_obj_itself(VALUE obj)
{
return obj;
}
|
#is_a? ⇒ Boolean #kind_of? ⇒ Boolean
Returns true
if class is the class of obj, or if class is one of the superclasses of obj or modules included in obj.
module M; end
class A
include M
end
class B < A; end
class C < B; end
b = B.new
b.is_a? A #=> true
b.is_a? B #=> true
b.is_a? C #=> false
b.is_a? M #=> true
b.kind_of? A #=> true
b.kind_of? B #=> true
b.kind_of? C #=> false
b.kind_of? M #=> true
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# File 'object.c', line 877
VALUE
rb_obj_is_kind_of(VALUE obj, VALUE c)
{
VALUE cl = CLASS_OF(obj);
c = class_or_module_required(c);
return class_search_ancestor(cl, RCLASS_ORIGIN(c)) ? Qtrue : Qfalse;
}
|
#method(sym) ⇒ Object
Looks up the named method as a receiver in obj, returning a Method object (or raising NameError). The Method object acts as a closure in obj’s object instance, so instance variables and the value of self
remain available.
class Demo
def initialize(n)
@iv = n
end
def hello()
"Hello, @iv = #{@iv}"
end
end
k = Demo.new(99)
m = k.method(:hello)
m.call #=> "Hello, @iv = 99"
l = Demo.new('Fred')
m = l.method("hello")
m.call #=> "Hello, @iv = Fred"
Note that Method implements to_proc
method, which means it can be used with iterators.
[ 1, 2, 3 ].each(&method(:puts)) # => prints 3 lines to stdout
out = File.open('test.txt', 'w')
[ 1, 2, 3 ].each(&out.method(:puts)) # => prints 3 lines to file
require 'date'
%w[2017-03-01 2017-03-02].collect(&Date.method(:parse))
#=> [#<Date: 2017-03-01 ((2457814j,0s,0n),+0s,2299161j)>, #<Date: 2017-03-02 ((2457815j,0s,0n),+0s,2299161j)>]
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# File 'proc.c', line 1991
VALUE
rb_obj_method(VALUE obj, VALUE vid)
{
return obj_method(obj, vid, FALSE);
}
|
#methods(regular = true) ⇒ Array
Returns a list of the names of public and protected methods of obj. This will include all the methods accessible in obj’s ancestors. If the optional parameter is false
, it returns an array of obj’s public and protected singleton methods, the array will not include methods in modules included in obj.
class Klass
def klass_method()
end
end
k = Klass.new
k.methods[0..9] #=> [:klass_method, :nil?, :===,
# :==~, :!, :eql?
# :hash, :<=>, :class, :singleton_class]
k.methods.length #=> 56
k.methods(false) #=> []
def k.singleton_method; end
k.methods(false) #=> [:singleton_method]
module M123; def m123; end end
k.extend M123
k.methods(false) #=> [:singleton_method]
1549 1550 1551 1552 1553 1554 1555 1556 1557 |
# File 'class.c', line 1549
VALUE
rb_obj_methods(int argc, const VALUE *argv, VALUE obj)
{
rb_check_arity(argc, 0, 1);
if (argc > 0 && !RTEST(argv[0])) {
return rb_obj_singleton_methods(argc, argv, obj);
}
return class_instance_method_list(argc, argv, CLASS_OF(obj), 1, ins_methods_i);
}
|
#nil? ⇒ Boolean
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# File 'object.c', line 1571
MJIT_FUNC_EXPORTED VALUE
rb_false(VALUE obj)
{
return Qfalse;
}
|
#object_id ⇒ Object
call-seq:
obj.__id__ -> integer
obj.object_id -> integer
Returns an integer identifier for obj
.
The same number will be returned on all calls to object_id
for a given object, and no two active objects will share an id.
Note: that some objects of builtin classes are reused for optimization. This is the case for immediate values and frozen string literals.
BasicObject implements __id__
, Kernel implements object_id
.
Immediate values are not passed by reference but are passed by value: nil
, true
, false
, Fixnums, Symbols, and some Floats.
Object.new.object_id == Object.new.object_id # => false
(21 * 2).object_id == (21 * 2).object_id # => true
"hello".object_id == "hello".object_id # => false
"hi".freeze.object_id == "hi".freeze.object_id # => true
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# File 'gc.c', line 4115
VALUE
rb_obj_id(VALUE obj)
{
/*
* 32-bit VALUE space
* MSB ------------------------ LSB
* false 00000000000000000000000000000000
* true 00000000000000000000000000000010
* nil 00000000000000000000000000000100
* undef 00000000000000000000000000000110
* symbol ssssssssssssssssssssssss00001110
* object oooooooooooooooooooooooooooooo00 = 0 (mod sizeof(RVALUE))
* fixnum fffffffffffffffffffffffffffffff1
*
* object_id space
* LSB
* false 00000000000000000000000000000000
* true 00000000000000000000000000000010
* nil 00000000000000000000000000000100
* undef 00000000000000000000000000000110
* symbol 000SSSSSSSSSSSSSSSSSSSSSSSSSSS0 S...S % A = 4 (S...S = s...s * A + 4)
* object oooooooooooooooooooooooooooooo0 o...o % A = 0
* fixnum fffffffffffffffffffffffffffffff1 bignum if required
*
* where A = sizeof(RVALUE)/4
*
* sizeof(RVALUE) is
* 20 if 32-bit, double is 4-byte aligned
* 24 if 32-bit, double is 8-byte aligned
* 40 if 64-bit
*/
return rb_find_object_id(obj, cached_object_id);
}
|
#private_methods(all = true) ⇒ Array
Returns the list of private methods accessible to obj. If the all parameter is set to false
, only those methods in the receiver will be listed.
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# File 'class.c', line 1583
VALUE
rb_obj_private_methods(int argc, const VALUE *argv, VALUE obj)
{
return class_instance_method_list(argc, argv, CLASS_OF(obj), 1, ins_methods_priv_i);
}
|
#protected_methods(all = true) ⇒ Array
Returns the list of protected methods accessible to obj. If the all parameter is set to false
, only those methods in the receiver will be listed.
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# File 'class.c', line 1568
VALUE
rb_obj_protected_methods(int argc, const VALUE *argv, VALUE obj)
{
return class_instance_method_list(argc, argv, CLASS_OF(obj), 1, ins_methods_prot_i);
}
|
#public_method(sym) ⇒ Object
Similar to method, searches public method only.
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# File 'proc.c', line 2004
VALUE
rb_obj_public_method(VALUE obj, VALUE vid)
{
return obj_method(obj, vid, TRUE);
}
|
#public_methods(all = true) ⇒ Array
Returns the list of public methods accessible to obj. If the all parameter is set to false
, only those methods in the receiver will be listed.
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# File 'class.c', line 1598
VALUE
rb_obj_public_methods(int argc, const VALUE *argv, VALUE obj)
{
return class_instance_method_list(argc, argv, CLASS_OF(obj), 1, ins_methods_pub_i);
}
|
#public_send(symbol[, args...]) ⇒ Object #public_send(string[, args...]) ⇒ Object
Invokes the method identified by symbol, passing it any arguments specified. Unlike send, public_send calls public methods only. When the method is identified by a string, the string is converted to a symbol.
1.public_send(:puts, "hello") # causes NoMethodError
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# File 'vm_eval.c', line 1154
static VALUE
rb_f_public_send(int argc, VALUE *argv, VALUE recv)
{
return send_internal_kw(argc, argv, recv, CALL_PUBLIC);
}
|
#remove_instance_variable(symbol) ⇒ Object #remove_instance_variable(string) ⇒ Object
Removes the named instance variable from obj, returning that variable’s value. String arguments are converted to symbols.
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
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# File 'variable.c', line 1855
VALUE
rb_obj_remove_instance_variable(VALUE obj, VALUE name)
{
VALUE val = Qnil;
const ID id = id_for_var(obj, name, an, instance);
st_data_t n, v;
struct st_table *iv_index_tbl;
uint32_t index;
rb_check_frozen(obj);
if (!id) {
goto not_defined;
}
switch (BUILTIN_TYPE(obj)) {
case T_OBJECT:
iv_index_tbl = ROBJECT_IV_INDEX_TBL(obj);
if (iv_index_tbl_lookup(iv_index_tbl, id, &index) &&
index < ROBJECT_NUMIV(obj) &&
(val = ROBJECT_IVPTR(obj)[index]) != Qundef) {
ROBJECT_IVPTR(obj)[index] = Qundef;
return val;
}
break;
case T_CLASS:
case T_MODULE:
IVAR_ACCESSOR_SHOULD_BE_MAIN_RACTOR(id);
n = id;
if (RCLASS_IV_TBL(obj) && st_delete(RCLASS_IV_TBL(obj), &n, &v)) {
return (VALUE)v;
}
break;
default:
if (FL_TEST(obj, FL_EXIVAR)) {
if (generic_ivar_remove(obj, id, &val)) {
return val;
}
}
break;
}
not_defined:
rb_name_err_raise("instance variable %1$s not defined",
obj, name);
UNREACHABLE_RETURN(Qnil);
}
|
#respond_to?(symbol, include_all = false) ⇒ Boolean #respond_to?(string, include_all = false) ⇒ Boolean
Returns true
if obj responds to the given method. Private and protected methods are included in the search only if the optional second parameter evaluates to true
.
If the method is not implemented, as Process.fork on Windows, File.lchmod on GNU/Linux, etc., false is returned.
If the method is not defined, respond_to_missing?
method is called and the result is returned.
When the method name parameter is given as a string, the string is converted to a symbol.
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# File 'vm_method.c', line 2547
static VALUE
obj_respond_to(int argc, VALUE *argv, VALUE obj)
{
VALUE mid, priv;
ID id;
rb_execution_context_t *ec = GET_EC();
rb_scan_args(argc, argv, "11", &mid, &priv);
if (!(id = rb_check_id(&mid))) {
VALUE ret = basic_obj_respond_to_missing(ec, CLASS_OF(obj), obj,
rb_to_symbol(mid), priv);
if (ret == Qundef) ret = Qfalse;
return ret;
}
if (basic_obj_respond_to(ec, CLASS_OF(obj), obj, id, !RTEST(priv)))
return Qtrue;
return Qfalse;
}
|
#respond_to_missing?(symbol, include_all) ⇒ Boolean #respond_to_missing?(string, include_all) ⇒ Boolean
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.
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# File 'vm_method.c', line 2581
static VALUE
obj_respond_to_missing(VALUE obj, VALUE mid, VALUE priv)
{
return Qfalse;
}
|
#send(symbol[, args...]) ⇒ Object #__send__(symbol[, args...]) ⇒ Object #send(string[, args...]) ⇒ Object #__send__(string[, args...]) ⇒ Object
Invokes the method identified by symbol, passing it any
arguments specified.
When the method is identified by a string, the string is converted
to a symbol.
BasicObject implements +__send__+, Kernel implements +send+.
<code>__send__</code> is safer than +send+
when _obj_ has the same method name like <code>Socket</code>.
See also <code>public_send</code>.
class Klass
def hello(*args)
"Hello " + args.join(' ')
end
end
k = Klass.new
k.send :hello, "gentle", "readers" #=> "Hello gentle readers"
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# File 'vm_eval.c', line 1134
VALUE
rb_f_send(int argc, VALUE *argv, VALUE recv)
{
return send_internal_kw(argc, argv, recv, CALL_FCALL);
}
|
#singleton_class ⇒ Class
Returns the singleton class of obj. This method creates a new singleton class if obj does not have one.
If obj is nil
, true
, or false
, it returns NilClass, TrueClass, or FalseClass, respectively. If obj is an Integer, a Float or a Symbol, it raises a TypeError.
Object.new.singleton_class #=> #<Class:#<Object:0xb7ce1e24>>
String.singleton_class #=> #<Class:String>
nil.singleton_class #=> NilClass
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# File 'object.c', line 317
static VALUE
rb_obj_singleton_class(VALUE obj)
{
return rb_singleton_class(obj);
}
|
#singleton_method(sym) ⇒ Object
Similar to method, searches singleton method only.
class Demo
def initialize(n)
@iv = n
end
def hello()
"Hello, @iv = #{@iv}"
end
end
k = Demo.new(99)
def k.hi
"Hi, @iv = #{@iv}"
end
m = k.singleton_method(:hi)
m.call #=> "Hi, @iv = 99"
m = k.singleton_method(:hello) #=> NameError
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# File 'proc.c', line 2034
VALUE
rb_obj_singleton_method(VALUE obj, VALUE vid)
{
VALUE klass = rb_singleton_class_get(obj);
ID id = rb_check_id(&vid);
if (NIL_P(klass)) {
/* goto undef; */
}
else if (NIL_P(klass = RCLASS_ORIGIN(klass))) {
/* goto undef; */
}
else if (! id) {
VALUE m = mnew_missing_by_name(klass, obj, &vid, FALSE, rb_cMethod);
if (m) return m;
/* else goto undef; */
}
else {
const rb_method_entry_t *me = rb_method_entry_at(klass, id);
vid = ID2SYM(id);
if (UNDEFINED_METHOD_ENTRY_P(me)) {
/* goto undef; */
}
else if (UNDEFINED_REFINED_METHOD_P(me->def)) {
/* goto undef; */
}
else {
return mnew_from_me(me, klass, klass, obj, id, rb_cMethod, FALSE);
}
}
/* undef: */
rb_name_err_raise("undefined singleton method `%1$s' for `%2$s'",
obj, vid);
UNREACHABLE_RETURN(Qundef);
}
|
#singleton_methods(all = true) ⇒ Array
Returns an array of the names of singleton methods for obj. If the optional all parameter is true, the list will include methods in modules included in obj. Only public and protected singleton methods are returned.
module Other
def three() end
end
class Single
def Single.four() end
end
a = Single.new
def a.one()
end
class << a
include Other
def two()
end
end
Single.singleton_methods #=> [:four]
a.singleton_methods(false) #=> [:two, :one]
a.singleton_methods #=> [:two, :one, :three]
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# File 'class.c', line 1637
VALUE
rb_obj_singleton_methods(int argc, const VALUE *argv, VALUE obj)
{
VALUE ary, klass, origin;
struct method_entry_arg me_arg;
struct rb_id_table *mtbl;
int recur = TRUE;
if (rb_check_arity(argc, 0, 1)) recur = RTEST(argv[0]);
if (RB_TYPE_P(obj, T_CLASS) && FL_TEST(obj, FL_SINGLETON)) {
rb_singleton_class(obj);
}
klass = CLASS_OF(obj);
origin = RCLASS_ORIGIN(klass);
me_arg.list = st_init_numtable();
me_arg.recur = recur;
if (klass && FL_TEST(klass, FL_SINGLETON)) {
if ((mtbl = RCLASS_M_TBL(origin)) != 0) rb_id_table_foreach(mtbl, method_entry_i, &me_arg);
klass = RCLASS_SUPER(klass);
}
if (recur) {
while (klass && (FL_TEST(klass, FL_SINGLETON) || RB_TYPE_P(klass, T_ICLASS))) {
if (klass != origin && (mtbl = RCLASS_M_TBL(klass)) != 0) rb_id_table_foreach(mtbl, method_entry_i, &me_arg);
klass = RCLASS_SUPER(klass);
}
}
ary = rb_ary_new2(me_arg.list->num_entries);
st_foreach(me_arg.list, ins_methods_i, ary);
st_free_table(me_arg.list);
return ary;
}
|
#taint ⇒ Object
Returns object. This method is deprecated and will be removed in Ruby 3.2.
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# File 'object.c', line 1173
VALUE
rb_obj_taint(VALUE obj)
{
rb_warn_deprecated_to_remove("Object#taint", "3.2");
return obj;
}
|
#tainted? ⇒ false
Returns false. This method is deprecated and will be removed in Ruby 3.2.
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# File 'object.c', line 1159
VALUE
rb_obj_tainted(VALUE obj)
{
rb_warn_deprecated_to_remove("Object#tainted?", "3.2");
return Qfalse;
}
|
#to_enum(method = :each, *args) ⇒ Enumerator #enum_for(method = :each, *args) ⇒ Enumerator #to_enum(method = :each, *args) {|*args| ... } ⇒ Enumerator #enum_for(method = :each, *args) {|*args| ... } ⇒ Enumerator
Creates a new Enumerator which will enumerate by calling method
on obj
, passing args
if any. What was yielded by method becomes values of enumerator.
If a block is given, it will be used to calculate the size of the enumerator without the need to iterate it (see Enumerator#size).
Examples
str = "xyz"
enum = str.enum_for(:each_byte)
enum.each { |b| puts b }
# => 120
# => 121
# => 122
# protect an array from being modified by some_method
a = [1, 2, 3]
some_method(a.to_enum)
# String#split in block form is more memory-effective:
very_large_string.split("|") { |chunk| return chunk if chunk.include?('DATE') }
# This could be rewritten more idiomatically with to_enum:
very_large_string.to_enum(:split, "|").lazy.grep(/DATE/).first
It is typical to call to_enum when defining methods for a generic Enumerable, in case no block is passed.
Here is such an example, with parameter passing and a sizing block:
module Enumerable
# a generic method to repeat the values of any enumerable
def repeat(n)
raise ArgumentError, "#{n} is negative!" if n < 0
unless block_given?
return to_enum(__method__, n) do # __method__ is :repeat here
sz = size # Call size and multiply by n...
sz * n if sz # but return nil if size itself is nil
end
end
each do |*val|
n.times { yield *val }
end
end
end
%i[hello world].repeat(2) { |w| puts w }
# => Prints 'hello', 'hello', 'world', 'world'
enum = (1..14).repeat(3)
# => returns an Enumerator when called without a block
enum.first(4) # => [1, 1, 1, 2]
enum.size # => 42
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# File 'enumerator.c', line 368
static VALUE
obj_to_enum(int argc, VALUE *argv, VALUE obj)
{
VALUE enumerator, meth = sym_each;
if (argc > 0) {
--argc;
meth = *argv++;
}
enumerator = rb_enumeratorize_with_size(obj, meth, argc, argv, 0);
if (rb_block_given_p()) {
enumerator_ptr(enumerator)->size = rb_block_proc();
}
return enumerator;
}
|
#to_s ⇒ String
Returns a string representing obj. The default #to_s prints the object’s class and an encoding of the object id. As a special case, the top-level object that is the initial execution context of Ruby programs returns “main”.
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# File 'object.c', line 671
VALUE
rb_any_to_s(VALUE obj)
{
VALUE str;
VALUE cname = rb_class_name(CLASS_OF(obj));
str = rb_sprintf("#<%"PRIsVALUE":%p>", cname, (void*)obj);
return str;
}
|
#trust ⇒ Object
Returns object. This method is deprecated and will be removed in Ruby 3.2.
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# File 'object.c', line 1231
VALUE
rb_obj_trust(VALUE obj)
{
rb_warn_deprecated_to_remove("Object#trust", "3.2");
return obj;
}
|
#untaint ⇒ Object
Returns object. This method is deprecated and will be removed in Ruby 3.2.
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# File 'object.c', line 1188
VALUE
rb_obj_untaint(VALUE obj)
{
rb_warn_deprecated_to_remove("Object#untaint", "3.2");
return obj;
}
|
#untrust ⇒ Object
Returns object. This method is deprecated and will be removed in Ruby 3.2.
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# File 'object.c', line 1216
VALUE
rb_obj_untrust(VALUE obj)
{
rb_warn_deprecated_to_remove("Object#untrust", "3.2");
return obj;
}
|
#untrusted? ⇒ false
Returns false. This method is deprecated and will be removed in Ruby 3.2.
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# File 'object.c', line 1202
VALUE
rb_obj_untrusted(VALUE obj)
{
rb_warn_deprecated_to_remove("Object#untrusted?", "3.2");
return Qfalse;
}
|