BasicObject

Not documented

                
static VALUE
rb_obj_dummy(void)
{
    return Qnil;
}

Boolean negate.

                
VALUE
rb_obj_not(VALUE obj)
{
    return RTEST(obj) ? Qfalse : Qtrue;
}

Returns true if two objects are not-equal, otherwise false.

                
VALUE
rb_obj_not_equal(VALUE obj1, VALUE obj2)
{
    VALUE result = rb_funcall(obj1, id_eq, 1, obj2);
    return RTEST(result) ? Qfalse : Qtrue;
}

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: it is used to determine object identity (that is, a.equal?(b) iff a is the same object as b).

The eql? method returns true if obj and anObject have the same value. Used by Hash to test members for equality. For objects of class Object, eql? is synonymous with ==. Subclasses normally continue this tradition, 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

                
VALUE
rb_obj_equal(VALUE obj1, VALUE obj2)
{
    if (obj1 == obj2) return Qtrue;
    return Qfalse;
}

Returns an integer identifier for obj. The same number will be returned on all calls to id for a given object, and no two active objects will share an id. Object#object_id is a different concept from the :name notation, which returns the symbol id of name. Replaces the deprecated Object#id.

                
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
     */
    if (SYMBOL_P(obj)) {
        return (SYM2ID(obj) * sizeof(RVALUE) + (4 << 2)) | FIXNUM_FLAG;
    }
    if (SPECIAL_CONST_P(obj)) {
        return LONG2NUM((SIGNED_VALUE)obj);
    }
    return (VALUE)((SIGNED_VALUE)obj|FIXNUM_FLAG);
}

Invokes the method identified by symbol, passing it any arguments specified. You can use __send__ if the name send clashes with an existing method in obj.

class Klass
  def hello(*args)
    "Hello " + args.join(' ')
  end
end
k = Klass.new
k.send :hello, "gentle", "readers"   #=> "Hello gentle readers"

                
VALUE
rb_f_send(int argc, VALUE *argv, VALUE recv)
{
    return send_internal(argc, argv, recv, CALL_FCALL);
}

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: it is used to determine object identity (that is, a.equal?(b) iff a is the same object as b).

The eql? method returns true if obj and anObject have the same value. Used by Hash to test members for equality. For objects of class Object, eql? is synonymous with ==. Subclasses normally continue this tradition, 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

                
VALUE
rb_obj_equal(VALUE obj1, VALUE obj2)
{
    if (obj1 == obj2) return Qtrue;
    return Qfalse;
}

Evaluates a string containing Ruby source code, or the given block, within the context of the receiver (obj). In order to set the context, the variable self is set to obj while the code is executing, giving the code access to obj’s instance variables. In the version of instance_eval that takes a String, the optional second and third parameters supply a filename and starting line number that are used when reporting compilation errors.

class KlassWithSecret
  def initialize
    @secret = 99
  end
end
k = KlassWithSecret.new
k.instance_eval { @secret }   #=> 99

                
VALUE
rb_obj_instance_eval(int argc, VALUE *argv, VALUE self)
{
    VALUE klass;

    if (SPECIAL_CONST_P(self)) {
        klass = Qnil;
    }
    else {
        klass = rb_singleton_class(self);
    }
    return specific_eval(argc, argv, klass, self);
}

Executes the given block within the context of the receiver (obj). In order to set the context, the variable self is set to obj while the code is executing, giving the code access to obj’s instance variables. Arguments are passed as block parameters.

class KlassWithSecret
  def initialize
    @secret = 99
  end
end
k = KlassWithSecret.new
k.instance_exec(5) {|x| @secret+x }   #=> 104

                
VALUE
rb_obj_instance_exec(int argc, VALUE *argv, VALUE self)
{
    VALUE klass;

    if (SPECIAL_CONST_P(self)) {
        klass = Qnil;
    }
    else {
        klass = rb_singleton_class(self);
    }
    return yield_under(klass, self, rb_ary_new4(argc, argv));
}