Class: Numeric
| Relationships & Source Files | |
| Extension / Inclusion / Inheritance Descendants | |
| Subclasses: | |
| Super Chains via Extension / Inclusion / Inheritance | |
| Instance Chain: 
          self,
           ::Comparable | |
| Inherits: | Object | 
| Defined in: | numeric.c, complex.c, rational.c | 
Overview
Numeric is the class from which all higher-level numeric classes should inherit.
Numeric allows instantiation of heap-allocated objects. Other core numeric classes such as ::Integer are implemented as immediates, which means that each ::Integer is a single immutable object which is always passed by value.
a = 1
1.object_id == a.object_id   #=> trueThere can only ever be one instance of the integer 1, for example. Ruby ensures this by preventing instantiation. If duplication is attempted, the same instance is returned.
Integer.new(1)                   #=> NoMethodError: undefined method `new' for Integer:Class
1.dup                            #=> 1
1.object_id == 1.dup.object_id   #=> trueFor this reason, Numeric should be used when defining other numeric classes.
Classes which inherit from Numeric must implement #coerce, which returns a two-member ::Array containing an object that has been coerced into an instance of the new class and self (see #coerce).
Inheriting classes should also implement arithmetic operator methods (+, -, * and /) and the #<=> operator (see ::Comparable). These methods may rely on #coerce to ensure interoperability with instances of other numeric classes.
class Tally < Numeric
  def initialize(string)
    @string = string
  end
  def to_s
    @string
  end
  def to_i
    @string.size
  end
  def coerce(other)
    [self.class.new('|' * other.to_i), self]
  end
  def <=>(other)
    to_i <=> other.to_i
  end
  def +(other)
    self.class.new('|' * (to_i + other.to_i))
  end
  def -(other)
    self.class.new('|' * (to_i - other.to_i))
  end
  def *(other)
    self.class.new('|' * (to_i * other.to_i))
  end
  def /(other)
    self.class.new('|' * (to_i / other.to_i))
  end
end
tally = Tally.new('||')
puts tally * 2            #=> "||||"
puts tally > 1            #=> trueInstance Attribute Summary
- 
    
      #finite?  ⇒ Boolean 
    
    readonly
    Returns trueifnumis a finite number, otherwise returnsfalse.
- 
    
      #infinite?  ⇒ Boolean 
    
    readonly
    Returns nil, -1, or 1 depending on whether the value is finite,-Infinity, or+Infinity.
- 
    
      #integer?  ⇒ Boolean 
    
    readonly
    Returns trueifnumis an::Integer.
- 
    
      #negative?  ⇒ Boolean 
    
    readonly
    Returns trueifnumis less than 0.
- 
    
      #nonzero?  ⇒ Boolean 
    
    readonly
    Returns selfifnumis not zero,nilotherwise.
- 
    
      #positive?  ⇒ Boolean 
    
    readonly
    Returns trueifnumis greater than 0.
- 
    
      #real  ⇒ self 
    
    readonly
    Returns self. 
- 
    
      #real?  ⇒ Boolean 
    
    readonly
    Returns trueifnumis a real number (i.e.
- 
    
      #zero?  ⇒ Boolean 
    
    readonly
    Returns trueifnumhas a zero value.
Instance Method Summary
- 
    
      #modulo(numeric)  ⇒ Numeric 
      (also: #modulo)
    
    x.modulo(y)meansx-y*(x/y).floor.
- 
    
      #+  ⇒ Numeric 
    
    Unary Plus—Returns the receiver. 
- 
    
      #-  ⇒ Numeric 
    
    Unary Minus—Returns the receiver, negated. 
- 
    
      #<=>(other)  ⇒ 0? 
    
    Returns zero if numberequalsother, otherwise returnsnil.
- 
    
      #abs  ⇒ Numeric 
      (also: #magnitude)
    
    Returns the absolute value of num.
- 
    
      #abs2  ⇒ Numeric 
    
    Returns square of self. 
- 
    
      #angle  ⇒ 0, Float 
    
    Alias for #arg. 
- 
    
      #arg  ⇒ 0, Float 
      (also: #angle, #phase)
    
    Returns 0 if the value is positive, pi otherwise. 
- 
    
      #ceil([ndigits])  ⇒ Integer, Float 
    
    Returns the smallest number greater than or equal to numwith a precision ofndigitsdecimal digits (default: 0).
- 
    
      #clone(freeze: true)  ⇒ Numeric 
    
    Returns the receiver. 
- 
    
      #coerce(numeric)  ⇒ Array 
    
    If numericis the same type asnum, returns an array[numeric, num].
- 
    
      #conj  ⇒ self 
      (also: #conjugate)
    
    Returns self. 
- 
    
      #conjugate  ⇒ self 
    
    Alias for #conj. 
- 
    
      #denominator  ⇒ Integer 
    
    Returns the denominator (always positive). 
- 
    
      #div(numeric)  ⇒ Integer 
    
    Uses /to perform division, then converts the result to an integer.
- 
    
      #divmod(numeric)  ⇒ Array 
    
    Returns an array containing the quotient and modulus obtained by dividing numbynumeric.
- 
    
      #dup  ⇒ Numeric 
    
    Returns the receiver. 
- 
    
      #eql?(numeric)  ⇒ Boolean 
    
    Returns trueifnumandnumericare the same type and have equal values.
- 
    
      #fdiv(numeric)  ⇒ Float 
    
    Returns float division. 
- 
    
      #floor([ndigits])  ⇒ Integer, Float 
    
    Returns the largest number less than or equal to numwith a precision ofndigitsdecimal digits (default: 0).
- 
    
      #i  ⇒ Complex(0, num) 
    
    Returns the corresponding imaginary number. 
- 
    
      #imag  ⇒ 0 
      (also: #imaginary)
    
    Returns zero. 
- 
    
      #imaginary  ⇒ 0 
    
    Alias for #imag. 
- 
    
      #magnitude  ⇒ Numeric 
    
    Alias for #abs. 
- 
    
      #modulo(numeric)  ⇒ Numeric 
    
    Alias for #%. 
- 
    
      #numerator  ⇒ Integer 
    
    Returns the numerator. 
- 
    
      #phase  ⇒ 0, Float 
    
    Alias for #arg. 
- 
    
      #polar  ⇒ Array 
    
    Returns an array; [num.abs, num.arg]. 
- 
    
      #quo(int_or_rat)  ⇒ rat 
    
    Returns the most exact division (rational for integers, float for floats). 
- 
    
      #rect  ⇒ Array 
      (also: #rectangular)
    
    Returns an array; [num, 0]. 
- 
    
      #rectangular  ⇒ Array 
    
    Alias for #rect. 
- 
    
      #remainder(numeric)  ⇒ Numeric 
    
    x.remainder(y)meansx-y*(x/y).truncate.
- 
    
      #round([ndigits])  ⇒ Integer, Float 
    
    Returns numrounded to the nearest value with a precision ofndigitsdecimal digits (default: 0).
- 
    
      #step(by: step, to: limit) {|i| ... } ⇒ self 
    
    Invokes the given block with the sequence of numbers starting at num, incremented bystep(defaulted to1) on each call.
- 
    
      #to_c  ⇒ Complex 
    
    Returns the value as a complex. 
- 
    
      #to_int  ⇒ Integer 
    
    Invokes the child class’s to_imethod to convertnumto an integer.
- 
    
      #truncate([ndigits])  ⇒ Integer, Float 
    
    Returns numtruncated (toward zero) to a precision ofndigitsdecimal digits (default: 0).
- 
    
      #singleton_method_added(name)  
    
    Internal use only
    Trap attempts to add methods to Numericobjects.
::Comparable - Included
| #< | Compares two objects based on the receiver’s #<=> method, returning true if it returns a value less than 0. | 
| #<= | Compares two objects based on the receiver’s #<=> method, returning true if it returns a value less than or equal to 0. | 
| #== | Compares two objects based on the receiver’s #<=> method, returning true if it returns 0. | 
| #> | Compares two objects based on the receiver’s #<=> method, returning true if it returns a value greater than 0. | 
| #>= | Compares two objects based on the receiver’s #<=> method, returning true if it returns a value greater than or equal to 0. | 
| #between? | |
| #clamp | 
Instance Attribute Details
    #finite?  ⇒ Boolean  (readonly)  
Returns true if num is a finite number, otherwise returns false.
# File 'numeric.c', line 806
static VALUE
num_finite_p(VALUE num)
{
    return Qtrue;
}
  
    #infinite?  ⇒ Boolean  (readonly)  
Returns nil, -1, or 1 depending on whether the value is finite, -Infinity, or +Infinity.
# File 'numeric.c', line 819
static VALUE
num_infinite_p(VALUE num)
{
    return Qnil;
}
  
    #integer?  ⇒ Boolean  (readonly)  
Returns true if num is an ::Integer.
1.0.integer?   #=> false
1.integer?     #=> true# File 'numeric.c', line 722
static VALUE
num_int_p(VALUE num)
{
    return Qfalse;
}
  
    #negative?  ⇒ Boolean  (readonly)  
Returns true if num is less than 0.
# File 'numeric.c', line 872
static VALUE
num_negative_p(VALUE num)
{
    return rb_num_negative_int_p(num) ? Qtrue : Qfalse;
}
  
    #nonzero?  ⇒ Boolean  (readonly)  
Returns self if num is not zero, nil otherwise.
This behavior is useful when chaining comparisons:
a = %w( z Bb bB bb BB a aA Aa AA A )
b = a.sort {|a,b| (a.downcase <=> b.downcase).nonzero? || a <=> b }
b   #=> ["A", "a", "AA", "Aa", "aA", "BB", "Bb", "bB", "bb", "z"]# File 'numeric.c', line 791
static VALUE
num_nonzero_p(VALUE num)
{
    if (RTEST(num_funcall0(num, rb_intern("zero?")))) {
	return Qnil;
    }
    return num;
}
  
    #positive?  ⇒ Boolean  (readonly)  
Returns true if num is greater than 0.
# File 'numeric.c', line 849
static VALUE
num_positive_p(VALUE num)
{
    const ID mid = '>';
    if (FIXNUM_P(num)) {
	if (method_basic_p(rb_cInteger))
	    return (SIGNED_VALUE)num > (SIGNED_VALUE)INT2FIX(0) ? Qtrue : Qfalse;
    }
    else if (RB_TYPE_P(num, T_BIGNUM)) {
	if (method_basic_p(rb_cInteger))
	    return BIGNUM_POSITIVE_P(num) && !rb_bigzero_p(num) ? Qtrue : Qfalse;
    }
    return rb_num_compare_with_zero(num, mid);
}
  
    #real  ⇒ self  (readonly)  
Returns self.
# File 'complex.c', line 2152
static VALUE
numeric_real(VALUE self)
{
    return self;
}
  
    #real?  ⇒ Boolean  (readonly)  
Returns true if num is a real number (i.e. not ::Complex).
# File 'numeric.c', line 706
static VALUE
num_real_p(VALUE num)
{
    return Qtrue;
}
  
    #zero?  ⇒ Boolean  (readonly)  
Returns true if num has a zero value.
# File 'numeric.c', line 758
static VALUE
num_zero_p(VALUE num)
{
    if (FIXNUM_P(num)) {
	if (FIXNUM_ZERO_P(num)) {
	    return Qtrue;
	}
    }
    else if (RB_TYPE_P(num, T_BIGNUM)) {
	if (rb_bigzero_p(num)) {
	    /* this should not happen usually */
	    return Qtrue;
	}
    }
    else if (rb_equal(num, INT2FIX(0))) {
	return Qtrue;
    }
    return Qfalse;
}
  Instance Method Details
    #modulo(numeric)  ⇒ Numeric     Also known as: #modulo
  
# File 'numeric.c', line 618
static VALUE
num_modulo(VALUE x, VALUE y)
{
    VALUE q = num_funcall1(x, id_div, y);
    return rb_funcall(x, '-', 1,
		      rb_funcall(y, '*', 1, q));
}
  
    #+  ⇒ Numeric   
Unary Plus—Returns the receiver.
# File 'numeric.c', line 534
static VALUE
num_uplus(VALUE num)
{
    return num;
}
  
    #-  ⇒ Numeric   
Unary Minus—Returns the receiver, negated.
# File 'numeric.c', line 564
static VALUE
num_uminus(VALUE num)
{
    VALUE zero;
    zero = INT2FIX(0);
    do_coerce(&zero, &num, TRUE);
    return num_funcall1(zero, '-', num);
}
  
    #<=>(other)  ⇒ 0?   
Returns zero if number equals other, otherwise returns nil.
# File 'numeric.c', line 1352
static VALUE
num_cmp(VALUE x, VALUE y)
{
    if (x == y) return INT2FIX(0);
    return Qnil;
}
  
    
      #abs  ⇒ Numeric 
      #magnitude  ⇒ Numeric 
    
    Also known as: #magnitude
  
Numeric 
      #magnitude  ⇒ Numeric 
    Returns the absolute value of num.
12.abs         #=> 12
(-34.56).abs   #=> 34.56
-34.56.abs     #=> 34.56#magnitude is an alias for abs.
# File 'numeric.c', line 742
static VALUE
num_abs(VALUE num)
{
    if (rb_num_negative_int_p(num)) {
	return num_funcall0(num, idUMinus);
    }
    return num;
}
  
    #abs2  ⇒ Numeric   
Returns square of self.
# File 'complex.c', line 2177
static VALUE
numeric_abs2(VALUE self)
{
    return f_mul(self, self);
}
  Alias for #arg.
Also known as: #angle, #phase
Returns 0 if the value is positive, pi otherwise.
# File 'complex.c', line 2191
static VALUE
numeric_arg(VALUE self)
{
    if (f_positive_p(self))
        return INT2FIX(0);
    return DBL2NUM(M_PI);
}
  #ceil([ndigits]) ⇒ Integer, Float
Returns the smallest number greater than or equal to num with a precision of ndigits decimal digits (default: 0).
Numeric implements this by converting its value to a ::Float and invoking Float#ceil.
# File 'numeric.c', line 2459
static VALUE
num_ceil(int argc, VALUE *argv, VALUE num)
{
    return flo_ceil(argc, argv, rb_Float(num));
}
  
    #clone(freeze: true)  ⇒ Numeric   
Returns the receiver.  freeze cannot be false.
# File 'numeric.c', line 502
static VALUE
num_clone(int argc, VALUE *argv, VALUE x)
{
    return rb_immutable_obj_clone(argc, argv, x);
}
  #coerce(numeric) ⇒ Array
If numeric is the same type as num, returns an array [numeric, num]. Otherwise, returns an array with both numeric and num represented as ::Float objects.
This coercion mechanism is used by Ruby to handle mixed-type numeric operations: it is intended to find a compatible common type between the two operands of the operator.
1.coerce(2.5)   #=> [2.5, 1.0]
1.2.coerce(3)   #=> [3.0, 1.2]
1.coerce(2)     #=> [2, 1]# File 'numeric.c', line 399
static VALUE
num_coerce(VALUE x, VALUE y)
{
    if (CLASS_OF(x) == CLASS_OF(y))
	return rb_assoc_new(y, x);
    x = rb_Float(x);
    y = rb_Float(y);
    return rb_assoc_new(y, x);
}
  
    
      #conj  ⇒ self 
      #conjugate  ⇒ self 
    
    Also known as: #conjugate
  
self 
      #conjugate  ⇒ self 
    Returns self.
# File 'complex.c', line 2251
static VALUE
numeric_conj(VALUE self)
{
    return self;
}
  
    
      #conj  ⇒ self 
      #conjugate  ⇒ self 
    
  
self 
      #conjugate  ⇒ self 
    Alias for #conj.
#denominator ⇒ Integer
Returns the denominator (always positive).
# File 'rational.c', line 2010
static VALUE
numeric_denominator(VALUE self)
{
    return f_denominator(f_to_r(self));
}
  #div(numeric) ⇒ Integer
Uses / to perform division, then converts the result to an integer. Numeric does not define the / operator; this is left to subclasses.
Equivalent to num.divmod(numeric)[0].
See #divmod.
# File 'numeric.c', line 600
static VALUE
num_div(VALUE x, VALUE y)
{
    if (rb_equal(INT2FIX(0), y)) rb_num_zerodiv();
    return rb_funcall(num_funcall1(x, '/', y), rb_intern("floor"), 0);
}
  #divmod(numeric) ⇒ Array
Returns an array containing the quotient and modulus obtained by dividing num by numeric.
If q, r = x.divmod(y), then
q = floor(x/y)
x = q*y + rThe quotient is rounded toward negative infinity, as shown in the following table:
 a    |  b  |  a.divmod(b)  |   a/b   | a.modulo(b) | a.remainder(b)
------------------------------------------------+---------------
 13   |  4  |   3,    1     |   3     |    1        |     1
------------------------------------------------+---------------
 13   | -4  |  -4,   -3     |  -4     |   -3        |     1
------------------------------------------------+---------------
-13   |  4  |  -4,    3     |  -4     |    3        |    -1
------------------------------------------------+---------------
-13   | -4  |   3,   -1     |   3     |   -1        |    -1
------------------------------------------------+---------------
 11.5 |  4  |   2,    3.5   |   2.875 |    3.5      |     3.5
------------------------------------------------+---------------
 11.5 | -4  |  -3,   -0.5   |  -2.875 |   -0.5      |     3.5
------------------------------------------------+---------------
-11.5 |  4  |  -3,    0.5   |  -2.875 |    0.5      |    -3.5
------------------------------------------------+---------------
-11.5 | -4  |   2,   -3.5   |   2.875 |   -3.5      |    -3.5Examples
11.divmod(3)        #=> [3, 2]
11.divmod(-3)       #=> [-4, -1]
11.divmod(3.5)      #=> [3, 0.5]
(-11).divmod(3.5)   #=> [-4, 3.0]
11.5.divmod(3.5)    #=> [3, 1.0]# File 'numeric.c', line 693
static VALUE
num_divmod(VALUE x, VALUE y)
{
    return rb_assoc_new(num_div(x, y), num_modulo(x, y));
}
  
    #dup  ⇒ Numeric   
Returns the receiver.
# File 'numeric.c', line 518
static VALUE
num_dup(VALUE x)
{
    return x;
}
  
    #eql?(numeric)  ⇒ Boolean   
Returns true if num and numeric are the same type and have equal values.  Contrast this with Numeric#==, which performs type conversions.
1 == 1.0        #=> true
1.eql?(1.0)     #=> false
1.0.eql?(1.0)   #=> true# File 'numeric.c', line 1333
static VALUE
num_eql(VALUE x, VALUE y)
{
    if (TYPE(x) != TYPE(y)) return Qfalse;
    if (RB_TYPE_P(x, T_BIGNUM)) {
	return rb_big_eql(x, y);
    }
    return rb_equal(x, y);
}
  #fdiv(numeric) ⇒ Float
Returns float division.
# File 'numeric.c', line 582
static VALUE
num_fdiv(VALUE x, VALUE y)
{
    return rb_funcall(rb_Float(x), '/', 1, y);
}
  #floor([ndigits]) ⇒ Integer, Float
Returns the largest number less than or equal to num with a precision of ndigits decimal digits (default: 0).
Numeric implements this by converting its value to a ::Float and invoking Float#floor.
# File 'numeric.c', line 2442
static VALUE
num_floor(int argc, VALUE *argv, VALUE num)
{
    return flo_floor(argc, argv, rb_Float(num));
}
  
    #i  ⇒ Complex(0, num)   
Returns the corresponding imaginary number. Not available for complex numbers.
-42.i  #=> (0-42i)
2.0.i  #=> (0+2.0i)# File 'numeric.c', line 551
static VALUE
num_imaginary(VALUE num)
{
    return rb_complex_new(INT2FIX(0), num);
}
  
    
      #imag  ⇒ 0 
      #imaginary  ⇒ 0 
    
    Also known as: #imaginary
  
0 
      #imaginary  ⇒ 0 
    Returns zero.
# File 'complex.c', line 2165
static VALUE
numeric_imag(VALUE self)
{
    return INT2FIX(0);
}
  
    
      #imag  ⇒ 0 
      #imaginary  ⇒ 0 
    
  
0 
      #imaginary  ⇒ 0 
    Alias for #imag.
    
      #abs  ⇒ Numeric 
      #magnitude  ⇒ Numeric 
    
  
Numeric 
      #magnitude  ⇒ Numeric 
    Alias for #abs.
    
      #modulo(numeric)  ⇒ Numeric 
      #modulo(numeric)  ⇒ Numeric 
    
  
Numeric 
      #modulo(numeric)  ⇒ Numeric 
    Alias for #%.
#numerator ⇒ Integer
Returns the numerator.
# File 'rational.c', line 1998
static VALUE
numeric_numerator(VALUE self)
{
    return f_numerator(f_to_r(self));
}
  Alias for #arg.
#polar ⇒ Array
Returns an array; [num.abs, num.arg].
# File 'complex.c', line 2220
static VALUE
numeric_polar(VALUE self)
{
    VALUE abs, arg;
    if (RB_INTEGER_TYPE_P(self)) {
        abs = rb_int_abs(self);
        arg = numeric_arg(self);
    }
    else if (RB_FLOAT_TYPE_P(self)) {
        abs = rb_float_abs(self);
        arg = float_arg(self);
    }
    else if (RB_TYPE_P(self, T_RATIONAL)) {
        abs = rb_rational_abs(self);
        arg = numeric_arg(self);
    }
    else {
        abs = f_abs(self);
        arg = f_arg(self);
    }
    return rb_assoc_new(abs, arg);
}
  
    
      #quo(int_or_rat)  ⇒ rat 
      #quo(flo)  ⇒ flo 
    
  
rat 
      #quo(flo)  ⇒ flo 
    Returns the most exact division (rational for integers, float for floats).
# File 'rational.c', line 2025
VALUE
rb_numeric_quo(VALUE x, VALUE y)
{
    if (RB_TYPE_P(x, T_COMPLEX)) {
        return rb_complex_div(x, y);
    }
    if (RB_FLOAT_TYPE_P(y)) {
        return rb_funcallv(x, idFdiv, 1, &y);
    }
    if (canonicalization) {
        x = rb_rational_raw1(x);
    }
    else {
        x = rb_convert_type(x, T_RATIONAL, "Rational", "to_r");
    }
    return rb_rational_div(x, y);
}
  Also known as: #rectangular
Returns an array; [num, 0].
# File 'complex.c', line 2206
static VALUE
numeric_rect(VALUE self)
{
    return rb_assoc_new(self, INT2FIX(0));
}
  Alias for #rect.
    #remainder(numeric)  ⇒ Numeric   
x.remainder(y) means x-y*(x/y).truncate.
See #divmod.
# File 'numeric.c', line 635
static VALUE
num_remainder(VALUE x, VALUE y)
{
    VALUE z = num_funcall1(x, '%', y);
    if ((!rb_equal(z, INT2FIX(0))) &&
	((rb_num_negative_int_p(x) &&
	  rb_num_positive_int_p(y)) ||
	 (rb_num_positive_int_p(x) &&
	  rb_num_negative_int_p(y)))) {
	return rb_funcall(z, '-', 1, y);
    }
    return z;
}
  #round([ndigits]) ⇒ Integer, Float
Returns num rounded to the nearest value with a precision of ndigits decimal digits (default: 0).
Numeric implements this by converting its value to a ::Float and invoking Float#round.
# File 'numeric.c', line 2476
static VALUE
num_round(int argc, VALUE* argv, VALUE num)
{
    return flo_round(argc, argv, rb_Float(num));
}
  #singleton_method_added(name)
Trap attempts to add methods to Numeric objects. Always raises a ::TypeError.
Numerics should be values; singleton_methods should not be added to them.
# File 'numeric.c', line 481
static VALUE
num_sadded(VALUE x, VALUE name)
{
    ID mid = rb_to_id(name);
    /* ruby_frame = ruby_frame->prev; */ /* pop frame for "singleton_method_added" */
    rb_remove_method_id(rb_singleton_class(x), mid);
    rb_raise(rb_eTypeError,
	     "can't define singleton method \"%"PRIsVALUE"\" for %"PRIsVALUE,
	     rb_id2str(mid),
	     rb_obj_class(x));
    UNREACHABLE_RETURN(Qnil);
}
  
    
      #step(by: step, to: limit) {|i| ... } ⇒ self 
      #step(by: step, to: limit)  ⇒ Enumerator 
      #step(by: step, to: limit)  ⇒ an_arithmetic_sequence 
      #step(limit = nil, step = 1) {|i| ... } ⇒ self 
      #step(limit = nil, step = 1)  ⇒ Enumerator 
      #step(limit = nil, step = 1)  ⇒ an_arithmetic_sequence 
    
  
self 
      #step(by: step, to: limit)  ⇒ Enumerator 
      #step(by: step, to: limit)  ⇒ an_arithmetic_sequence 
      #step(limit = nil, step = 1) {|i| ... } ⇒ self 
      #step(limit = nil, step = 1)  ⇒ Enumerator 
      #step(limit = nil, step = 1)  ⇒ an_arithmetic_sequence 
    Invokes the given block with the sequence of numbers starting at num, incremented by step (defaulted to 1) on each call.
The loop finishes when the value to be passed to the block is greater than limit (if step is positive) or less than limit (if step is negative), where limit is defaulted to infinity.
In the recommended keyword argument style, either or both of step and limit (default infinity) can be omitted.  In the fixed position argument style, zero as a step (i.e. num.step(limit, 0)) is not allowed for historical compatibility reasons.
If all the arguments are integers, the loop operates using an integer counter.
If any of the arguments are floating point numbers, all are converted to floats, and the loop is executed floor(n + n*Float::EPSILON) + 1 times, where n = (limit - num)/step.
Otherwise, the loop starts at num, uses either the less-than (<) or greater-than (>) operator to compare the counter against limit, and increments itself using the + operator.
If no block is given, an ::Enumerator is returned instead. Especially, the enumerator is an ::Enumerator::ArithmeticSequence if both limit and step are kind of Numeric or nil.
For example:
p 1.step.take(4)
p 10.step(by: -1).take(4)
3.step(to: 5) {|i| print i, " " }
1.step(10, 2) {|i| print i, " " }
Math::E.step(to: Math::PI, by: 0.2) {|f| print f, " " }Will produce:
[1, 2, 3, 4]
[10, 9, 8, 7]
3 4 5
1 3 5 7 9
2.718281828459045 2.9182818284590453 3.118281828459045# File 'numeric.c', line 2755
static VALUE
num_step(int argc, VALUE *argv, VALUE from)
{
    VALUE to, step;
    int desc, inf;
    if (!rb_block_given_p()) {
        VALUE by = Qundef;
        num_step_extract_args(argc, argv, &to, &step, &by);
        if (by != Qundef) {
            step = by;
        }
        if (NIL_P(step)) {
            step = INT2FIX(1);
        }
        if ((NIL_P(to) || rb_obj_is_kind_of(to, rb_cNumeric)) &&
            rb_obj_is_kind_of(step, rb_cNumeric)) {
            return rb_arith_seq_new(from, ID2SYM(rb_frame_this_func()), argc, argv,
                                    num_step_size, from, to, step, FALSE);
        }
        return SIZED_ENUMERATOR(from, 2, ((VALUE [2]){to, step}), num_step_size);
    }
    desc = num_step_scan_args(argc, argv, &to, &step, TRUE, FALSE);
    if (rb_equal(step, INT2FIX(0))) {
	inf = 1;
    }
    else if (RB_TYPE_P(to, T_FLOAT)) {
	double f = RFLOAT_VALUE(to);
	inf = isinf(f) && (signbit(f) ? desc : !desc);
    }
    else inf = 0;
    if (FIXNUM_P(from) && (inf || FIXNUM_P(to)) && FIXNUM_P(step)) {
	long i = FIX2LONG(from);
	long diff = FIX2LONG(step);
	if (inf) {
	    for (;; i += diff)
		rb_yield(LONG2FIX(i));
	}
	else {
	    long end = FIX2LONG(to);
	    if (desc) {
		for (; i >= end; i += diff)
		    rb_yield(LONG2FIX(i));
	    }
	    else {
		for (; i <= end; i += diff)
		    rb_yield(LONG2FIX(i));
	    }
	}
    }
    else if (!ruby_float_step(from, to, step, FALSE, FALSE)) {
	VALUE i = from;
	if (inf) {
	    for (;; i = rb_funcall(i, '+', 1, step))
		rb_yield(i);
	}
	else {
	    ID cmp = desc ? '<' : '>';
	    for (; !RTEST(rb_funcall(i, cmp, 1, to)); i = rb_funcall(i, '+', 1, step))
		rb_yield(i);
	}
    }
    return from;
}
  #to_c ⇒ Complex
Returns the value as a complex.
# File 'complex.c', line 1697
static VALUE
numeric_to_c(VALUE self)
{
    return rb_complex_new1(self);
}
  #to_int ⇒ Integer
Invokes the child class’s to_i method to convert num to an integer.
1.0.class          #=> Float
1.0.to_int.class   #=> Integer
1.0.to_i.class     #=> Integer# File 'numeric.c', line 836
static VALUE
num_to_int(VALUE num)
{
    return num_funcall0(num, id_to_i);
}
  #truncate([ndigits]) ⇒ Integer, Float
Returns num truncated (toward zero) to a precision of ndigits decimal digits (default: 0).
Numeric implements this by converting its value to a ::Float and invoking Float#truncate.
# File 'numeric.c', line 2493
static VALUE
num_truncate(int argc, VALUE *argv, VALUE num)
{
    return flo_truncate(argc, argv, rb_Float(num));
}