The class of the singleton object nil
.
static VALUE
false_and(VALUE obj, VALUE obj2)
{
return Qfalse;
}
And—Returns false
. obj is always evaluated as it is the argument to a method call—there is no short-circuit evaluation in this case.
VALUE
rb_equal(VALUE obj1, VALUE obj2)
{
VALUE result;
if (obj1 == obj2) return Qtrue;
result = rb_equal_opt(obj1, obj2);
if (result == Qundef) {
result = rb_funcall(obj1, id_eq, 1, obj2);
}
if (RTEST(result)) return Qtrue;
return Qfalse;
}
Case Equality – For class Object
, effectively the same as calling #==
, but typically overridden by descendants to provide meaningful semantics in case
statements.
static VALUE
false_xor(VALUE obj, VALUE obj2)
{
return RTEST(obj2)?Qtrue:Qfalse;
}
Exclusive Or—If obj is nil
or false
, returns false
; otherwise, returns true
.
static VALUE
nil_inspect(VALUE obj)
{
return rb_usascii_str_new2("nil");
}
Always returns the string “nil”.
static VALUE
rb_true(VALUE obj)
{
return Qtrue;
}
Only the object nil responds true
to nil?
.
static VALUE
nilclass_rationalize(int argc, VALUE *argv, VALUE self)
{
rb_scan_args(argc, argv, "01", NULL);
return nilclass_to_r(self);
}
Returns zero as a rational. The optional argument eps
is always ignored.
static VALUE
nil_to_a(VALUE obj)
{
return rb_ary_new2(0);
}
Always returns an empty array.
nil.to_a #=> []
static VALUE
nilclass_to_c(VALUE self)
{
return rb_complex_new1(INT2FIX(0));
}
Returns zero as a complex.
static VALUE
nil_to_f(VALUE obj)
{
return DBL2NUM(0.0);
}
Always returns zero.
nil.to_f #=> 0.0
static VALUE
nil_to_h(VALUE obj)
{
return rb_hash_new();
}
Always returns an empty hash.
nil.to_h #=> {}
static VALUE
nil_to_i(VALUE obj)
{
return INT2FIX(0);
}
Always returns zero.
nil.to_i #=> 0
static VALUE
nilclass_to_r(VALUE self)
{
return rb_rational_new1(INT2FIX(0));
}
Returns zero as a rational.
static VALUE
nil_to_s(VALUE obj)
{
return rb_usascii_str_new(0, 0);
}
Always returns the empty string.
static VALUE
false_or(VALUE obj, VALUE obj2)
{
return RTEST(obj2)?Qtrue:Qfalse;
}
Or—Returns false
if obj is nil
or false
; true
otherwise.