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, numeric.rb, 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 #=> true
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) #=> NoMethodError: undefined method `new' for Integer:Class
1.dup #=> 1
1.object_id == 1.dup.object_id #=> true
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 > 1 #=> true
What’s Here
First, what’s elsewhere. Class Numeric:
-
Inherits from
class Object
. -
Includes
module Comparable
.
Here, class Numeric provides methods for:
-
Querying
-
Comparing
-
Converting
-
Other
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.
Comparing
-
#<=>: 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
ifself
and the given value are not comparable.
-
-
#eql?: Returns whether
self
and the given value have the same value and type.
Converting
-
#% (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 dividingself
the given divisor. -
#fdiv: Returns the
::Float
result of dividingself
by the given divisor. -
#floor: Returns the largest number less than or equal to
self
, to a given precision. -
#i: Returns the
::Complex
objectComplex(0, self)
. the given value. -
#imaginary (aliased as #imag): Returns the imaginary part of the
self
. -
#numerator: Returns the numerator of the
::Rational
representation ofself
; has the same sign asself
. -
#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 ofself
, truncating if necessary. -
#truncate: Returns
self
truncated (toward zero) to a given precision.
Other
Instance Attribute Summary
-
#finite? ⇒ Boolean
readonly
Returns
true
ifself
is a finite number,false
otherwise. -
#infinite? ⇒ Boolean
readonly
Returns
nil
, -1, or 1 depending on whetherself
is finite,-Infinity
, or+Infinity
. -
#integer? ⇒ Boolean
readonly
Returns
true
ifself
is an::Integer
. -
#negative? ⇒ Boolean
readonly
Returns
true
ifself
is less than 0,false
otherwise. -
#nonzero? ⇒ Boolean
readonly
Returns
self
ifself
is not a zero value,nil
otherwise; uses method #zero? for the evaluation. -
#positive? ⇒ Boolean
readonly
Returns
true
ifself
is greater than 0,false
otherwise. -
#real? ⇒ Boolean
readonly
Returns
true
ifself
is a real number (i.e. -
#zero? ⇒ Boolean
readonly
Returns
true
ifzero
has a zero value,false
otherwise.
Instance Method Summary
-
#%(other) ⇒ Numeric
(also: #modulo)
Returns
self
moduloother
as a real number. -
#+ ⇒ self
Returns
self
. -
#- ⇒ Numeric
Unary Minus—Returns the receiver, negated.
-
#<=>(other) ⇒ zero?
Returns zero if
self
is the same asother
,nil
otherwise. -
#abs ⇒ Numeric
(also: #magnitude)
Returns the absolute value of
self
. -
#abs2 ⇒ Numeric
Returns the square of
self
. -
#angle ⇒ 0, Math::PI
Alias for #arg.
-
#arg ⇒ 0, Math::PI
(also: #angle, #phase)
Returns zero if
self
is positive, Math::PI otherwise. -
#ceil(ndigits = 0) ⇒ Float, Integer
Returns the smallest float or integer that is greater than or equal to
self
, as specified by the givenndigits
, which must be aninteger-convertible object
. -
#clone(freeze: true) ⇒ self
Returns
self
. -
#coerce(other) ⇒ Array
Returns a 2-element array containing two numeric elements, formed from the two operands
self
andother
, of a common compatible type. -
#conj
Alias for #conjugate.
-
#conj ⇒ self
(also: #conj)
Returns
self
. -
#denominator ⇒ Integer
Returns the denominator (always positive).
-
#div(other) ⇒ Integer
Returns the quotient
self/other
as an integer (via #floor), using method/
in the derived class ofself
. -
#divmod(other) ⇒ Array
Returns a 2-element array
[q, r]
, where. -
#dup ⇒ self
Returns
self
. -
#eql?(other) ⇒ Boolean
Returns
true
ifself
andother
are the same type and have equal values. -
#fdiv(other) ⇒ Float
Returns the quotient
self/other
as a float, using method/
in the derived class ofself
. -
#floor(ndigits = 0) ⇒ Float, Integer
Returns the largest float or integer that is less than or equal to
self
, as specified by the givenndigits
, which must be aninteger-convertible object
. -
#i ⇒ Complex
Returns
Complex(0, self)
: -
#imag
Alias for #imaginary.
-
#imag ⇒ 0
(also: #imag)
Returns zero.
-
#magnitude ⇒ Numeric
Alias for #abs.
-
#modulo(other) ⇒ Numeric
Alias for #%.
-
#numerator ⇒ Integer
Returns the numerator.
-
#phase ⇒ 0, Math::PI
Alias for #arg.
-
#polar ⇒ Array
Returns array
[self.abs, self.arg]
. -
#quo(int_or_rat) ⇒ rat
Returns the most exact division (rational for integers, float for floats).
-
#real ⇒ self
readonly
Returns
self
. -
#rect ⇒ Array
(also: #rectangular)
Returns array
[self, 0]
. -
#rectangular ⇒ Array
Alias for #rect.
-
#remainder(other) ⇒ real_number
Returns the remainder after dividing
self
byother
. -
#round(digits = 0) ⇒ Integer, Float
Returns
self
rounded to the nearest value with a precision ofdigits
decimal digits. -
#step(to = nil, by = 1) {|n| ... } ⇒ self
Generates a sequence of numbers; with a block given, traverses the sequence.
-
#to_c ⇒ Complex
Returns
self
as a::Complex
object. -
#to_int ⇒ Integer
Returns
self
as an integer; converts using methodto_i
in the derived class. -
#truncate(digits = 0) ⇒ Integer, Float
Returns
self
truncated (toward zero) to a precision ofdigits
decimal digits. -
#singleton_method_added(name)
Internal use only
Trap attempts to add methods to
Numeric
objects.
::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 self
is a finite number, false
otherwise.
# File 'numeric.rb', line 48
def finite? true end
#infinite? ⇒ Boolean
(readonly)
Returns nil
, -1, or 1 depending on whether self
is finite, -Infinity
, or +Infinity
.
# File 'numeric.rb', line 58
def infinite? nil end
#integer? ⇒ Boolean
(readonly)
Returns true
if self
is an ::Integer
.
1.0.integer? # => false
1.integer? # => true
# File 'numeric.rb', line 39
def integer? false end
#negative? ⇒ Boolean
(readonly)
Returns true
if self
is less than 0, false
otherwise.
# File 'numeric.c', line 902
static VALUE num_negative_p(VALUE num) { return RBOOL(rb_num_negative_int_p(num)); }
#nonzero? ⇒ Boolean
(readonly)
Returns self
if self
is not a zero value, nil
otherwise; uses method #zero? 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?
# File 'numeric.c', line 836
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 self
is greater than 0, false
otherwise.
# File 'numeric.c', line 878
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); }
#real? ⇒ Boolean
(readonly)
Returns true
if self
is a real number (i.e. not ::Complex
).
# File 'numeric.rb', line 18
def real? true end
#zero? ⇒ Boolean
(readonly)
Returns true
if zero
has a zero value, false
otherwise.
Of the Core and Standard Library classes, only ::Rational
and ::Complex
use this implementation.
# File 'numeric.c', line 794
static VALUE num_zero_p(VALUE num) { return rb_equal(num, INT2FIX(0)); }
Instance Method Details
#%(other) ⇒ Numeric
Also known as: #modulo
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 #divmod.
Examples:
r = Rational(1, 2) # => (1/2)
r2 = Rational(2, 3) # => (2/3)
r % r2 # => (1/2)
r % 2 # => (1/2)
r % 2.0 # => 0.5
r = Rational(301,100) # => (301/100)
r2 = Rational(7,5) # => (7/5)
r % r2 # => (21/100)
r % -r2 # => (-119/100)
(-r) % r2 # => (119/100)
(-r) %-r2 # => (-21/100)
# File 'numeric.c', line 666
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)); }
#+ ⇒ self
Returns self
.
# File 'numeric.rb', line 89
def +@ self end
#- ⇒ Numeric
Unary Minus—Returns the receiver, negated.
# File 'numeric.c', line 582
static VALUE num_uminus(VALUE num) { VALUE zero; zero = INT2FIX(0); do_coerce(&zero, &num, TRUE); return num_funcall1(zero, '-', num); }
#<=>(other) ⇒ zero
?
Returns zero if self
is the same as other
, nil
otherwise.
No subclass in the Ruby Core or Standard Library uses this implementation.
# File 'numeric.c', line 1551
static VALUE num_cmp(VALUE x, VALUE y) { if (x == y) return INT2FIX(0); return Qnil; }
#abs ⇒ Numeric
Also known as: #magnitude
Returns the absolute value of self
.
12.abs #=> 12
(-34.56).abs #=> 34.56
-34.56.abs #=> 34.56
# File 'numeric.c', line 774
static VALUE num_abs(VALUE num) { if (rb_num_negative_int_p(num)) { return num_funcall0(num, idUMinus); } return num; }
#abs2 ⇒ Numeric
Returns the square of self
.
# File 'complex.c', line 2385
static VALUE numeric_abs2(VALUE self) { return f_mul(self, self); }
Alias for #arg.
#arg ⇒ 0
, Math::PI Also known as: #angle, #phase
Returns zero if self
is positive, Math::PI otherwise.
# File 'complex.c', line 2397
static VALUE numeric_arg(VALUE self) { if (f_positive_p(self)) return INT2FIX(0); return DBL2NUM(M_PI); }
#ceil(ndigits = 0) ⇒ Float, Integer
Returns the smallest float or integer that is greater than or equal to self
, as specified by the given ndigits
, which must be an integer-convertible object
.
Equivalent to self.to_f.ceil(ndigits)
.
Related: #floor, Float#ceil.
# File 'numeric.c', line 2740
static VALUE num_ceil(int argc, VALUE *argv, VALUE num) { return flo_ceil(argc, argv, rb_Float(num)); }
#clone(freeze: true) ⇒ self
# File 'numeric.c', line 546
static VALUE num_clone(int argc, VALUE *argv, VALUE x) { return rb_immutable_obj_clone(argc, argv, x); }
#coerce(other) ⇒ Array
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 # => 2
i.coerce(3) # => [3, 2]
i.coerce(3.0) # => [3.0, 2.0]
i.coerce(Rational(1, 2)) # => [0.5, 2.0]
i.coerce(Complex(3, 4)) # Raises RangeError.
r = Rational(5, 2) # => (5/2)
r.coerce(2) # => [(2/1), (5/2)]
r.coerce(2.0) # => [2.0, 2.5]
r.coerce(Rational(2, 3)) # => [(2/3), (5/2)]
r.coerce(Complex(3, 4)) # => [(3+4i), ((5/2)+0i)]
c = Complex(2, 3) # => (2+3i)
c.coerce(2) # => [(2+0i), (2+3i)]
c.coerce(2.0) # => [(2.0+0i), (2+3i)]
c.coerce(Rational(1, 2)) # => [((1/2)+0i), (2+3i)]
c.coerce(Complex(3, 4)) # => [(3+4i), (2+3i)]
Raises an exception if any type conversion fails.
# File 'numeric.c', line 430
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
Alias for #conjugate.
# File 'numeric.rb', line 82
alias conj conjugate
#conj ⇒ self
Also known as: #conj
Returns self
.
# File 'numeric.rb', line 78
def conjugate self end
#denominator ⇒ Integer
Returns the denominator (always positive).
# File 'rational.c', line 2028
static VALUE numeric_denominator(VALUE self) { return f_denominator(f_to_r(self)); }
#div(other) ⇒ Integer
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.
# File 'numeric.c', line 625
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(other) ⇒ Array
Returns a 2-element array [q, r]
, where
q = (self/other).floor # Quotient
r = self % other # Remainder
Of the Core and Standard Library classes, only ::Rational
uses this implementation.
Examples:
Rational(11, 1).divmod(4) # => [2, (3/1)]
Rational(11, 1).divmod(-4) # => [-3, (-1/1)]
Rational(-11, 1).divmod(4) # => [-3, (1/1)]
Rational(-11, 1).divmod(-4) # => [2, (-3/1)]
Rational(12, 1).divmod(4) # => [3, (0/1)]
Rational(12, 1).divmod(-4) # => [-3, (0/1)]
Rational(-12, 1).divmod(4) # => [-3, (0/1)]
Rational(-12, 1).divmod(-4) # => [3, (0/1)]
Rational(13, 1).divmod(4.0) # => [3, 1.0]
Rational(13, 1).divmod(Rational(4, 11)) # => [35, (3/11)]
# File 'numeric.c', line 756
static VALUE num_divmod(VALUE x, VALUE y) { return rb_assoc_new(num_div(x, y), num_modulo(x, y)); }
#dup ⇒ self
Returns self
.
Related: #clone.
# File 'numeric.rb', line 9
def dup self end
#eql?(other) ⇒ Boolean
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) # => true
1.eql?(1.0) # => false
1.eql?(Rational(1, 1)) # => false
1.eql?(Complex(1, 0)) # => false
Method eql?
is different from ==
in that eql?
requires matching types, while ==
does not.
# File 'numeric.c', line 1529
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); }
#fdiv(other) ⇒ Float
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.
# File 'numeric.c', line 606
static VALUE num_fdiv(VALUE x, VALUE y) { return rb_funcall(rb_Float(x), '/', 1, y); }
#floor(ndigits = 0) ⇒ Float, Integer
Returns the largest float or integer that is less than or equal to self
, as specified by the given ndigits
, which must be an integer-convertible object
.
Equivalent to self.to_f.floor(ndigits)
.
Related: #ceil, Float#floor.
# File 'numeric.c', line 2720
static VALUE num_floor(int argc, VALUE *argv, VALUE num) { return flo_floor(argc, argv, rb_Float(num)); }
#i ⇒ Complex
# File 'numeric.c', line 569
static VALUE num_imaginary(VALUE num) { return rb_complex_new(INT2FIX(0), num); }
#imag
Alias for #imaginary.
# File 'numeric.rb', line 71
alias imag imaginary
#imag ⇒ 0
Also known as: #imag
Returns zero.
# File 'numeric.rb', line 67
def imaginary 0 end
#abs ⇒ Numeric
#magnitude ⇒ Numeric
Numeric
#magnitude ⇒ Numeric
Alias for #abs.
#%(other) ⇒ Numeric
#modulo(other) ⇒ Numeric
Numeric
#modulo(other) ⇒ Numeric
Alias for #%.
#numerator ⇒ Integer
Returns the numerator.
# File 'rational.c', line 2016
static VALUE numeric_numerator(VALUE self) { return f_numerator(f_to_r(self)); }
Alias for #arg.
#polar ⇒ Array
Returns array [self.abs, self.arg]
.
# File 'complex.c', line 2423
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 2043
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); }
#real ⇒ self
(readonly)
Returns self
.
# File 'numeric.rb', line 27
def real self end
#rect ⇒ Array Also known as: #rectangular
Returns array [self, 0]
.
# File 'complex.c', line 2411
static VALUE numeric_rect(VALUE self) { return rb_assoc_new(self, INT2FIX(0)); }
Alias for #rect.
#remainder(other) ⇒ real_number
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) # => 3.0
11.0.remainder(-4) # => 3.0
-11.0.remainder(4) # => -3.0
-11.0.remainder(-4) # => -3.0
12.0.remainder(4) # => 0.0
12.0.remainder(-4) # => 0.0
-12.0.remainder(4) # => -0.0
-12.0.remainder(-4) # => -0.0
13.0.remainder(4.0) # => 1.0
13.0.remainder(Rational(4, 1)) # => 1.0
Rational(13, 1).remainder(4) # => (1/1)
Rational(13, 1).remainder(-4) # => (1/1)
Rational(-13, 1).remainder(4) # => (-1/1)
Rational(-13, 1).remainder(-4) # => (-1/1)
# File 'numeric.c', line 705
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; }
#round(digits = 0) ⇒ Integer, Float
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.
# File 'numeric.c', line 2757
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 520
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(to = nil, by = 1) {|n| ... } ⇒ self
#step(to = nil, by = 1) ⇒ Enumerator
#step(to = nil, by: 1) {|n| ... } ⇒ self
#step(to = nil, by: 1) ⇒ Enumerator
#step(by: 1, to::) {|n| ... } ⇒ self
#step(by: 1, to::) ⇒ Enumerator
#step(by::, to: nil) {|n| ... } ⇒ self
#step(by::, to: nil) ⇒ Enumerator
self
#step(to = nil, by = 1) ⇒ Enumerator
#step(to = nil, by: 1) {|n| ... } ⇒ self
#step(to = nil, by: 1) ⇒ Enumerator
#step(by: 1, to::) {|n| ... } ⇒ self
#step(by: 1, to::) ⇒ Enumerator
#step(by::, to: nil) {|n| ... } ⇒ self
#step(by::, to: nil) ⇒ Enumerator
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 # => [1, 9, 25, 49, 81]
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 toto
ifby
is positive, greater than or equal toto
ifby
is negative. Ifto
isnil
, 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:
# Both keywords given.
squares = []
4.step(by: 2, to: 10) {|i| squares.push(i*i) } # => 4
squares # => [16, 36, 64, 100]
cubes = []
3.step(by: -1.5, to: -3) {|i| cubes.push(i*i*i) } # => 3
cubes # => [27.0, 3.375, 0.0, -3.375, -27.0]
squares = []
1.2.step(by: 0.2, to: 2.0) {|f| squares.push(f*f) }
squares # => [1.44, 1.9599999999999997, 2.5600000000000005, 3.24, 4.0]
squares = []
Rational(6/5).step(by: 0.2, to: 2.0) {|r| squares.push(r*r) }
squares # => [1.0, 1.44, 1.9599999999999997, 2.5600000000000005, 3.24, 4.0]
# Only keyword to given.
squares = []
4.step(to: 10) {|i| squares.push(i*i) } # => 4
squares # => [16, 25, 36, 49, 64, 81, 100]
# Only by given.
# Only keyword by given
squares = []
4.step(by:2) {|i| squares.push(i*i); break if i > 10 }
squares # => [16, 36, 64, 100, 144]
# No block given.
e = 3.step(by: -1.5, to: -3) # => (3.step(by: -1.5, to: -3))
e.class # => Enumerator::ArithmeticSequence
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) } # => 4
squares # => [16, 36, 64, 100]
squares = []
4.step(10) {|i| squares.push(i*i) }
squares # => [16, 25, 36, 49, 64, 81, 100]
squares = []
4.step {|i| squares.push(i*i); break if i > 10 } # => nil
squares # => [16, 25, 36, 49, 64, 81, 100, 121]
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.
# File 'numeric.c', line 3094
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; }
#to_c ⇒ Complex
Returns self
as a ::Complex
object.
# File 'complex.c', line 1948
static VALUE numeric_to_c(VALUE self) { return rb_complex_new1(self); }
#to_int ⇒ Integer
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 # => 0
Rational(2, 1).to_int # => 2
Complex(2, 0).to_int # => 2
Complex(2, 1) # Raises RangeError (non-zero imaginary part)
# File 'numeric.c', line 864
static VALUE num_to_int(VALUE num) { return num_funcall0(num, id_to_i); }
#truncate(digits = 0) ⇒ Integer, Float
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.
# File 'numeric.c', line 2774
static VALUE num_truncate(int argc, VALUE *argv, VALUE num) { return flo_truncate(argc, argv, rb_Float(num)); }