mirror of
https://github.com/mruby/mruby
synced 2026-06-08 16:11:16 +00:00
Yukihiro "Matz" Matsumoto
fe3c3bb661
- Implement `Rational()` in `C`. - Use `float` to `rational` conversion function taken from: https://rosettacode.org/wiki/Convert_decimal_number_to_rational#C
108 lines
2.6 KiB
Ruby
108 lines
2.6 KiB
Ruby
class Rational < Numeric
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def inspect
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"(#{to_s})"
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end
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def to_s
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"#{numerator}/#{denominator}"
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end
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def *(rhs)
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if rhs.is_a? Rational
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Rational(numerator * rhs.numerator, denominator * rhs.denominator)
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elsif rhs.is_a? Integer
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Rational(numerator * rhs, denominator)
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elsif rhs.is_a? Numeric
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numerator * rhs / denominator
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end
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end
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def +(rhs)
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if rhs.is_a? Rational
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Rational(numerator * rhs.denominator + rhs.numerator * denominator, denominator * rhs.denominator)
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elsif rhs.is_a? Integer
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Rational(numerator + rhs * denominator, denominator)
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elsif rhs.is_a? Numeric
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(numerator + rhs * denominator) / denominator
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end
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end
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def -(rhs)
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if rhs.is_a? Rational
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Rational(numerator * rhs.denominator - rhs.numerator * denominator, denominator * rhs.denominator)
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elsif rhs.is_a? Integer
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Rational(numerator - rhs * denominator, denominator)
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elsif rhs.is_a? Numeric
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(numerator - rhs * denominator) / denominator
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end
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end
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def /(rhs)
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if rhs.is_a? Rational
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Rational(numerator * rhs.denominator, denominator * rhs.numerator)
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elsif rhs.is_a? Integer
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Rational(numerator, denominator * rhs)
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elsif rhs.is_a? Numeric
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numerator / rhs / denominator
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end
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end
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def <=>(rhs)
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case rhs
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when Integer, Float
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return numerator <=> rhs if denominator == 1
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rhs = Rational(rhs)
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end
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case rhs
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when Rational
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(numerator * rhs.denominator - denominator * rhs.numerator) <=> 0
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when Numeric
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(rhs <=> self)&.-@
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else
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nil
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end
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end
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def ==(rhs)
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return true if self.equal?(rhs)
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case rhs
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when Integer, Float
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return numerator == rhs if denominator == 1
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when Rational
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return numerator * rhs.denominator == denominator * rhs.numerator
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end
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rhs == self
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end
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end
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class Numeric
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def to_r
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Rational(self, 1)
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end
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end
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module Kernel
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[:+, :-, :*, :/, :<=>, :==, :<, :<=, :>, :>=].each do |op|
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original_operator_name = :"__original_operator_#{op}_rational"
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Integer.instance_eval do
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alias_method original_operator_name, op
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define_method op do |rhs|
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if rhs.is_a? Rational
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Rational(self).__send__(op, rhs)
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else
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__send__(original_operator_name, rhs)
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end
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end
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end
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Float.instance_eval do
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alias_method original_operator_name, op
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define_method op do |rhs|
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if rhs.is_a? Rational
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rhs = rhs.to_f
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end
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__send__(original_operator_name, rhs)
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end
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end if Object.const_defined?(:Float)
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end
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end
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