Rational Reference
Number stored as numerator and denominator
What it is #
Routines #
Signatures are reproduced from the documentation, including their declared return types. A routine listed here is part of the type's published interface; whether Raku++ implements it is a separate question, answered by the examples below.
method new #
method new(NuT:D $numerator, DeT:D $denominator --> Rational:D)Returns Rational:D.
Creates a new rational object from numerator and denominator, which it normalizes to the lowest terms. The $denominator can be zero, in which case the numerator is normalized to -1, 0, or 1 depending on whether the original is negative, zero, or positive, respectively.
method Bool #
multi method Bool(Rational:D: --> Bool:D)Returns Bool:D.
Returns False if numerator is 0, otherwise returns True. This applies for <0/0> zero-denominator <Rational as well, despite ?<0/0>.Num being True.
method Bridge #
method Bridge()Returns the number, converted to Num.
method Int #
method Int(Rational:D: --> Int:D)Returns Int:D.
Coerces the invocant to Int by truncating non-whole portion of the represented number, if any. If the denominator is zero, will fail with X::Numeric::DivideByZero.
method Num #
method Num(Rational:D: --> Num:D)Returns Num:D.
Coerces the invocant to Num by dividing numerator by denominator. If denominator is 0, returns Inf, -Inf, or NaN, based on whether numerator is a positive number, negative number, or 0, respectively.
method ceiling #
method ceiling(Rational:D: --> Int:D)Returns Int:D.
Return the smallest integer not less than the invocant. If denominator is zero, fails with X::Numeric::DivideByZero.
method floor #
method floor(Rational:D: --> Int:D)Returns Int:D.
Return the largest integer not greater than the invocant. If denominator is zero, fails with X::Numeric::DivideByZero.
method isNaN #
method isNaN(Rational:D: --> Bool:D)Returns Bool:D.
Tests whether the invocant's Num value is a NaN, an acronym for Not available Number. That is both its numerator and denominator are zero.
method numerator #
method numerator(Rational:D: --> NuT:D)Returns NuT:D.
Returns the numerator.
method denominator #
method denominator(Rational:D: --> DeT:D)Returns DeT:D.
Returns the denominator.
method nude #
method nude(Rational:D: --> Positional)Returns Positional.
Returns a list of the numerator and denominator.
method norm #
method norm(Rational:D: --> Rational:D)Returns Rational:D.
DEPRECATED as of 6.d. The method is no longer needed, because as of 6.d language version, it's required for Rational type to be normalized on creation. Returns a normalized Rational object, i.e. with positive denominator, and numerator and denominator coprime. The denominator can also be zero, but using it in any operation or a conversion to string will result in an exception.
method base-repeating #
method base-repeating(Rational:D: Int:D() $base = 10)Returns a list of two strings that, when concatenated, represent the number in base $base. The second element is the one that repeats. For example: 19/3 is 6.333333... with the 3 repeating indefinitely. If no repetition occurs, the second string is empty: The precision for determining the repeating group is limited to 1000 characters, above that, the second string is ???. $base defaults to 10.
method Range #
Returns a Range object that represents the range of values supported.
Examples, run three ways #
Every example below comes from the official documentation, together with the output that documentation asserts. Each was then executed by Rakudo and by Raku++ when this page was built. Where the three agree, one result is shown; where they do not, all three are — because which of them is wrong is exactly the information worth having.
5 no-output · 1 not-runnable · 3 ok
role Rational[::NuT, ::DeT] does Real { ... }Not executed: the documentation states no expected output for this example.
class Positive does Rational[UInt] {};
my Positive $one-third = Positive.new(1,3);
say $one-third; # OUTPUT: «0.333333»
my Positive $fail =Positive.new(-2,3); # OUTPUT: «Type check failed in binding to parameter 'nu'; expected UInt but got Int (-2)»Neither engine can run this in isolation — the example depends on context from the surrounding text.
=begin code :preamble<subset NuT of Int; subset DeT of Int> =end code
Not executed: the documentation states no expected output for this example.
=begin code :preamble<subset NuT of Int; subset DeT of Int> =end code
Not executed: the documentation states no expected output for this example.
=begin code :preamble<subset NuT of Int; subset DeT of Int> =end code
Not executed: the documentation states no expected output for this example.
use v6.c; my Rational $by-zero = 3/0; say $by-zero.norm.raku; # OUTPUT: «<1/0>»
<1/0>
Documentation, Rakudo and Raku++ all agree.
say $by-zero; # OUTPUT: «Attempt to divide by zero when coercing Rational to Str
Not executed: the documentation states no expected output for this example.
my ($non-rep, $repeating) = (19/3).base-repeating(10); say $non-rep; # OUTPUT: «6.» say $repeating; # OUTPUT: «3» printf '%s(%s)', $non-rep, $repeating; # OUTPUT: «6.(3)»
6.
3
6.(3)Documentation, Rakudo and Raku++ all agree.
say (5/2).base-repeating(10).raku; # OUTPUT: «("2.5", "")»("2.5", "")
Documentation, Rakudo and Raku++ all agree.