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
There 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) 1.dup 1.object_id == 1.dup.object_id
For 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 > 1Whatâs Here¶ ↑
First, whatâs elsewhere. Class Numeric:
Inherits from class Object.
Includes module Comparable.
Here, class Numeric provides methods for:
Querying¶ ↑finite?
: Returns true unless self
is infinite or not a number.
infinite?
: Returns -1, nil
or +1, depending on whether self
is -Infinity<tt>, finite, or <tt>+Infinity
.
integer?
: Returns whether self
is an integer.
negative?
: Returns whether self
is negative.
nonzero?
: Returns whether self
is not zero.
positive?
: Returns whether self
is positive.
real?
: Returns whether self
is a real value.
zero?
: Returns whether self
is zero.
<=>
: Returns:
-1 if self
is less than the given value.
0 if self
is equal to the given value.
1 if self
is greater than the given value.
nil
if self
and the given value are not comparable.
eql?
: Returns whether self
and the given value have the same value and type.
%
(aliased as modulo
): Returns the remainder of self
divided by the given value.
-@
: Returns the value of self
, negated.
abs
(aliased as magnitude
): Returns the absolute value of self
.
abs2
: Returns the square of self
.
angle
(aliased as arg
and phase
): Returns 0 if self
is positive, Math::PI otherwise.
ceil
: Returns the smallest number greater than or equal to self
, to a given precision.
coerce
: Returns array [coerced_self, coerced_other]
for the given other value.
conj
(aliased as conjugate
): Returns the complex conjugate of self
.
denominator
: Returns the denominator (always positive) of the Rational
representation of self
.
div
: Returns the value of self
divided by the given value and converted to an integer.
divmod
: Returns array [quotient, modulus]
resulting from dividing self
the given divisor.
fdiv
: Returns the Float
result of dividing self
by the given divisor.
floor
: Returns the largest number less than or equal to self
, to a given precision.
i
: Returns the Complex
object Complex(0, self)
. the given value.
imaginary
(aliased as imag
): Returns the imaginary part of the self
.
numerator
: Returns the numerator of the Rational
representation of self
; has the same sign as self
.
polar
: Returns the array [self.abs, self.arg]
.
quo
: Returns the value of self
divided by the given value.
real
: Returns the real part of self
.
rect
(aliased as rectangular
): Returns the array [self, 0]
.
remainder
: Returns self-arg*(self/arg).truncate
for the given arg
.
round
: Returns the value of self
rounded to the nearest value for the given a precision.
to_int
: Returns the Integer
representation of self
, truncating if necessary.
truncate
: Returns self
truncated (toward zero) to a given precision.
clone
: Returns self
; does not allow freezing.
step
: Invokes the given block with the sequence of specified numbers.
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)); }
Returns self
modulo other
as a real number.
Of the Core and Standard Library classes, only Rational
uses this implementation.
For Rational
r
and real number n
, these expressions are equivalent:
r % n r-n*(r/n).floor r.divmod(n)[1]
See Numeric#divmod
.
Examples:
r = Rational(1, 2) r2 = Rational(2, 3) r % r2 r % 2 r % 2.0 r = Rational(301,100) r2 = Rational(7,5) r % r2 r % -r2 (-r) % r2 (-r) %-r2Source
static VALUE num_uminus(VALUE num) { VALUE zero; zero = INT2FIX(0); do_coerce(&zero, &num, TRUE); return num_funcall1(zero, '-', num); }
Unary MinusâReturns the receiver, negated.
Sourcestatic VALUE num_cmp(VALUE x, VALUE y) { if (x == y) return INT2FIX(0); return Qnil; }
Returns zero if self
is the same as other
, nil
otherwise.
No subclass in the Ruby Core or Standard Library uses this implementation.
Sourcestatic VALUE num_abs(VALUE num) { if (rb_num_negative_int_p(num)) { return num_funcall0(num, idUMinus); } return num; }
Returns the absolute value of self
.
12.abs (-34.56).abs -34.56.absSource
static VALUE numeric_abs2(VALUE self) { return f_mul(self, self); }
Returns the square of self
.
static VALUE numeric_arg(VALUE self) { if (f_positive_p(self)) return INT2FIX(0); return DBL2NUM(M_PI); }
Returns zero if self
is positive, Math::PI otherwise.
static VALUE num_ceil(int argc, VALUE *argv, VALUE num) { return flo_ceil(argc, argv, rb_Float(num)); }
Returns the smallest float or integer that is greater than or equal to self
, as specified by the given ândigits`, which must be an integer-convertible object.
Equivalent to self.to_f.ceil(ndigits)
.
Related: floor
, Float#ceil
.
static VALUE num_clone(int argc, VALUE *argv, VALUE x) { return rb_immutable_obj_clone(argc, argv, x); }
Returns self
.
Raises an exception if the value for freeze
is neither true
nor nil
.
Related: Numeric#dup
.
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); }
Returns a 2-element array containing two numeric elements, formed from the two operands self
and other
, of a common compatible type.
Of the Core and Standard Library classes, Integer
, Rational
, and Complex
use this implementation.
Examples:
i = 2 i.coerce(3) i.coerce(3.0) i.coerce(Rational(1, 2)) i.coerce(Complex(3, 4)) r = Rational(5, 2) r.coerce(2) r.coerce(2.0) r.coerce(Rational(2, 3)) r.coerce(Complex(3, 4)) c = Complex(2, 3) c.coerce(2) c.coerce(2.0) c.coerce(Rational(1, 2)) c.coerce(Complex(3, 4))
Raises an exception if any type conversion fails.
Sourcestatic VALUE numeric_denominator(VALUE self) { return f_denominator(f_to_r(self)); }
Returns the denominator (always positive).
Sourcestatic 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); }
Returns the quotient self/other
as an integer (via floor
), using method /
in the derived class of self
. (Numeric itself does not define method /
.)
Of the Core and Standard Library classes, Only Float
and Rational
use this implementation.
static VALUE num_divmod(VALUE x, VALUE y) { return rb_assoc_new(num_div(x, y), num_modulo(x, y)); }
Returns a 2-element array [q, r]
, where
q = (self/other).floor r = self % other
Of the Core and Standard Library classes, only Rational
uses this implementation.
Examples:
Rational(11, 1).divmod(4) Rational(11, 1).divmod(-4) Rational(-11, 1).divmod(4) Rational(-11, 1).divmod(-4) Rational(12, 1).divmod(4) Rational(12, 1).divmod(-4) Rational(-12, 1).divmod(4) Rational(-12, 1).divmod(-4) Rational(13, 1).divmod(4.0) Rational(13, 1).divmod(Rational(4, 11))Source
static VALUE num_eql(VALUE x, VALUE y) { if (TYPE(x) != TYPE(y)) return Qfalse; if (RB_BIGNUM_TYPE_P(x)) { return rb_big_eql(x, y); } return rb_equal(x, y); }
Returns true
if self
and other
are the same type and have equal values.
Of the Core and Standard Library classes, only Integer
, Rational
, and Complex
use this implementation.
Examples:
1.eql?(1) 1.eql?(1.0) 1.eql?(Rational(1, 1)) 1.eql?(Complex(1, 0))
Method eql?
is different from ==
in that eql?
requires matching types, while ==
does not.
static VALUE num_fdiv(VALUE x, VALUE y) { return rb_funcall(rb_Float(x), '/', 1, y); }
Returns the quotient self/other
as a float, using method /
in the derived class of self
. (Numeric itself does not define method /
.)
Of the Core and Standard Library classes, only BigDecimal
uses this implementation.
Returns true
if self
is a finite number, false
otherwise.
static VALUE num_floor(int argc, VALUE *argv, VALUE num) { return flo_floor(argc, argv, rb_Float(num)); }
Returns the largest float or integer that is less than or equal to self
, as specified by the given ândigits`, which must be an integer-convertible object.
Equivalent to self.to_f.floor(ndigits)
.
Related: ceil
, Float#floor
.
static VALUE num_imaginary(VALUE num) { return rb_complex_new(INT2FIX(0), num); }
Returns Complex(0, self)
:
2.i -2.i 2.0.i Rational(1, 2).i Complex(3, 4).iSource
Returns nil
, -1, or 1 depending on whether self
is finite, -Infinity
, or +Infinity
.
Returns true
if self
is an Integer
.
1.0.integer? 1.integer?Source
static VALUE num_negative_p(VALUE num) { return RBOOL(rb_num_negative_int_p(num)); }
Returns true
if self
is less than 0, false
otherwise.
static VALUE num_nonzero_p(VALUE num) { if (RTEST(num_funcall0(num, rb_intern("zero?")))) { return Qnil; } return num; }
Returns +self+ if +self+ is not a zero value, +nil+ otherwise; uses method <tt>zero?</tt> for the evaluation. The returned +self+ allows the method to be chained: a = %w[z Bb bB bb BB a aA Aa AA A] a.sort {|a, b| (a.downcase <=> b.downcase).nonzero? || a <=> b } # => ["A", "a", "AA", "Aa", "aA", "BB", "Bb", "bB", "bb", "z"] Of the Core and Standard Library classes, Integer, Float, Rational, and Complex use this implementation.
Related: zero?
static VALUE numeric_numerator(VALUE self) { return f_numerator(f_to_r(self)); }
Returns the numerator.
Sourcestatic 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); }
Returns array [self.abs, self.arg]
.
static VALUE num_positive_p(VALUE num) { const ID mid = '>'; if (FIXNUM_P(num)) { if (method_basic_p(rb_cInteger)) return RBOOL((SIGNED_VALUE)num > (SIGNED_VALUE)INT2FIX(0)); } else if (RB_BIGNUM_TYPE_P(num)) { if (method_basic_p(rb_cInteger)) return RBOOL(BIGNUM_POSITIVE_P(num) && !rb_bigzero_p(num)); } return rb_num_compare_with_zero(num, mid); }
Returns true
if self
is greater than 0, false
otherwise.
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); } x = rb_convert_type(x, T_RATIONAL, "Rational", "to_r"); return rb_rational_div(x, y); }
Returns the most exact division (rational for integers, float for floats).
SourceReturns true
if self
is a real number (i.e. not Complex
).
static VALUE num_remainder(VALUE x, VALUE y) { if (!rb_obj_is_kind_of(y, rb_cNumeric)) { do_coerce(&x, &y, TRUE); } 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)))) { if (RB_FLOAT_TYPE_P(y)) { if (isinf(RFLOAT_VALUE(y))) { return x; } } return rb_funcall(z, '-', 1, y); } return z; }
Returns the remainder after dividing self
by other
.
Of the Core and Standard Library classes, only Float
and Rational
use this implementation.
Examples:
11.0.remainder(4) 11.0.remainder(-4) -11.0.remainder(4) -11.0.remainder(-4) 12.0.remainder(4) 12.0.remainder(-4) -12.0.remainder(4) -12.0.remainder(-4) 13.0.remainder(4.0) 13.0.remainder(Rational(4, 1)) Rational(13, 1).remainder(4) Rational(13, 1).remainder(-4) Rational(-13, 1).remainder(4) Rational(-13, 1).remainder(-4)Source
static VALUE num_round(int argc, VALUE* argv, VALUE num) { return flo_round(argc, argv, rb_Float(num)); }
Returns self
rounded to the nearest value with a precision of digits
decimal digits.
Numeric implements this by converting self
to a Float
and invoking Float#round
.
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 (!UNDEF_P(by)) { step = by; } if (NIL_P(step)) { step = INT2FIX(1); } else if (rb_equal(step, INT2FIX(0))) { rb_raise(rb_eArgError, "step can't be 0"); } 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_KW(from, 2, ((VALUE [2]){to, step}), num_step_size, FALSE); } desc = num_step_scan_args(argc, argv, &to, &step, TRUE, FALSE); if (rb_equal(step, INT2FIX(0))) { inf = 1; } else if (RB_FLOAT_TYPE_P(to)) { 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; }
Generates a sequence of numbers; with a block given, traverses the sequence.
Of the Core and Standard Library classes, Integer
, Float
, and Rational
use this implementation.
A quick example:
squares = [] 1.step(by: 2, to: 10) {|i| squares.push(i*i) } squares
The generated sequence:
Begins with self
.
Continues at intervals of by
(which may not be zero).
Ends with the last number that is within or equal to to
; that is, less than or equal to to
if by
is positive, greater than or equal to to
if by
is negative. If to
is nil
, the sequence is of infinite length.
If a block is given, calls the block with each number in the sequence; returns self
. If no block is given, returns an Enumerator::ArithmeticSequence
.
Keyword Arguments
With keyword arguments by
and to
, their values (or defaults) determine the step and limit:
squares = [] 4.step(by: 2, to: 10) {|i| squares.push(i*i) } squares cubes = [] 3.step(by: -1.5, to: -3) {|i| cubes.push(i*i*i) } cubes squares = [] 1.2.step(by: 0.2, to: 2.0) {|f| squares.push(f*f) } squares squares = [] Rational(6/5).step(by: 0.2, to: 2.0) {|r| squares.push(r*r) } squares squares = [] 4.step(to: 10) {|i| squares.push(i*i) } squares squares = [] 4.step(by:2) {|i| squares.push(i*i); break if i > 10 } squares e = 3.step(by: -1.5, to: -3) e.class
Positional Arguments
With optional positional arguments to
and by
, their values (or defaults) determine the step and limit:
squares = [] 4.step(10, 2) {|i| squares.push(i*i) } squares squares = [] 4.step(10) {|i| squares.push(i*i) } squares squares = [] 4.step {|i| squares.push(i*i); break if i > 10 } squares
Implementation Notes
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 - self)/step.
Sourcestatic VALUE numeric_to_c(VALUE self) { return rb_complex_new1(self); }
Returns self
as a Complex
object.
static VALUE num_to_int(VALUE num) { return num_funcall0(num, id_to_i); }
Returns self
as an integer; converts using method to_i
in the derived class.
Of the Core and Standard Library classes, only Rational
and Complex
use this implementation.
Examples:
Rational(1, 2).to_int Rational(2, 1).to_int Complex(2, 0).to_int Complex(2, 1).to_intSource
static VALUE num_truncate(int argc, VALUE *argv, VALUE num) { return flo_truncate(argc, argv, rb_Float(num)); }
Returns self
truncated (toward zero) to a precision of digits
decimal digits.
Numeric implements this by converting self
to a Float
and invoking Float#truncate
.
static VALUE num_zero_p(VALUE num) { return rb_equal(num, INT2FIX(0)); }
Returns true
if zero
has a zero value, false
otherwise.
Of the Core and Standard Library classes, only Rational
and Complex
use this implementation.
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4