Basic implementation of Complex and Rational classes

3 files changed, 115 insertions, 29 deletions

diff --git a/mrbgems/mruby-rational/mrbgem.rake b/mrbgems/mruby-rational/mrbgem.rake
index 4b540dec4..496082709 100644
--- a/mrbgems/mruby-rational/mrbgem.rake
+++ b/mrbgems/mruby-rational/mrbgem.rake
@@ -2,4 +2,7 @@ MRuby::Gem::Specification.new('mruby-rational') do |spec|
   spec.license = 'MIT'
   spec.author  = 'mruby developers'
   spec.summary = 'Rational class'
+
+  spec.add_dependency 'mruby-object-ext', core: 'mruby-object-ext'
+  spec.add_dependency 'mruby-numeric-ext', core: 'mruby-numeric-ext'
 end
diff --git a/mrbgems/mruby-rational/mrblib/rational.rb b/mrbgems/mruby-rational/mrblib/rational.rb
index 457c0488a..ffadd55eb 100644
--- a/mrbgems/mruby-rational/mrblib/rational.rb
+++ b/mrbgems/mruby-rational/mrblib/rational.rb
@@ -2,45 +2,89 @@ class Rational < Numeric
   def initialize(numerator = 0, denominator = 1)
     @numerator = numerator
     @denominator = denominator
+
+    _simplify
   end
 
-  attr_reader :numerator, :denominator
-end
+  def inspect
+    "(#{to_s})"
+  end
 
-def Rational(numerator = 0, denominator = 1)
-  Rational.new(numerator, denominator)
-end
+  def to_s
+    "#{numerator}/#{denominator}"
+  end
 
-module ForwardOperatorToRational
-  def __forward_operator_to_rational(op, &b)
-    original_operator_name = "__original_operator_#{op}_rational"
-    alias_method original_operator_name, op
-    define_method op do |rhs|
-      if rhs.is_a? Rational
-        Rational.new(self).send(op, rhs)
-      else
-        send(original_operator_name, rhs)
-      end
+  def *(rhs)
+    if rhs.is_a? Rational
+      Rational(numerator * rhs.numerator, denominator * rhs.denominator)
+    elsif rhs.is_a? Integer
+      Rational(numerator * rhs, denominator)
+    elsif rhs.is_a? Numeric
+      numerator * rhs / denominator
+    end
+  end
+
+  def +(rhs)
+    if rhs.is_a? Rational
+      Rational(numerator * rhs.denominator + rhs.numerator * denominator, denominator * rhs.denominator)
+    elsif rhs.is_a? Integer
+      Rational(numerator + rhs * denominator, denominator)
+    elsif rhs.is_a? Numeric
+      (numerator + rhs * denominator) / denominator
+    end
+  end
+
+  def -(rhs)
+    if rhs.is_a? Rational
+      Rational(numerator * rhs.denominator - rhs.numerator * denominator, denominator * rhs.denominator)
+    elsif rhs.is_a? Integer
+      Rational(numerator - rhs * denominator, denominator)
+    elsif rhs.is_a? Numeric
+      (numerator - rhs * denominator) / denominator
     end
   end
 
-  def __forward_operators_to_rational
-    __forward_operator_to_rational :+
-    __forward_operator_to_rational :-
-    __forward_operator_to_rational :*
-    __forward_operator_to_rational :/
+  def /(rhs)
+    if rhs.is_a? Rational
+      Rational(numerator * rhs.denominator, denominator * rhs.numerator)
+    elsif rhs.is_a? Integer
+      Rational(numerator, denominator * rhs)
+    elsif rhs.is_a? Numeric
+      numerator / rhs / denominator
+    end
+  end
 
-    singleton_class.undef_method :__forward_operator_to_rational
-    singleton_class.undef_method :__forward_operators_to_rational
+  def negative?
+    numerator.negative?
   end
+
+  def _simplify
+    a = numerator
+    b = denominator
+    a, b = b, a % b while !b.zero?
+    @numerator /= a
+    @denominator /= a
+  end
+
+  attr_reader :numerator, :denominator
 end
 
-class Fixnum
-  extend ForwardOperatorToRational
-  __forward_operators_to_rational
+def Rational(numerator = 0, denominator = 1)
+  Rational.new(numerator, denominator)
 end
 
-class Float
-  extend ForwardOperatorToRational
-  __forward_operators_to_rational
+[Fixnum, Float].each do |cls|
+  [:+, :-, :*, :/, :==].each do |op|
+    cls.instance_exec do
+      original_operator_name = "__original_operator_#{op}_rational"
+      alias_method original_operator_name, op
+      define_method op do |rhs|
+        if rhs.is_a? Rational
+          Rational(self).send(op, rhs)
+        else
+          send(original_operator_name, rhs)
+        end
+      end
+    end
+  end
 end
\ No newline at end of file
diff --git a/mrbgems/mruby-rational/test/rational.rb b/mrbgems/mruby-rational/test/rational.rb
index 6f20a6cd4..a86f00690 100644
--- a/mrbgems/mruby-rational/test/rational.rb
+++ b/mrbgems/mruby-rational/test/rational.rb
@@ -1,3 +1,42 @@
+def assert_rational(real, exp)
+  assert_float real.numerator,   exp.numerator        
+  assert_float real.denominator, exp.denominator
+end
+
 assert 'Rational' do
-  assert_equal Rational, 0r.class
+  r = 5r
+  assert_equal Rational, r.class
+  assert_equal [r.numerator, r.denominator], [5, 1]
+end
+
+assert 'Rational#*' do
+  assert_rational Rational(2, 3)  * Rational(2, 3),  Rational(4, 9)
+  assert_rational Rational(900)   * Rational(1),     Rational(900, 1)
+  assert_rational Rational(-2, 9) * Rational(-9, 2), Rational(1, 1)
+  assert_rational Rational(9, 8)  * 4,               Rational(9, 2)
+  assert_float    Rational(20, 9) * 9.8,             21.77777777777778
+end
+
+assert 'Rational#+' do
+  assert_rational Rational(2, 3)  + Rational(2, 3),  Rational(4, 3)
+  assert_rational Rational(900)   + Rational(1),     Rational(901, 1)
+  assert_rational Rational(-2, 9) + Rational(-9, 2), Rational(-85, 18)
+  assert_rational Rational(9, 8)  + 4,               Rational(41, 8)
+  assert_float    Rational(20, 9) + 9.8,             12.022222222222222
+end
+
+assert 'Rational#-' do
+  assert_rational Rational(2, 3)  - Rational(2, 3),  Rational(0, 1)
+  assert_rational Rational(900)   - Rational(1),     Rational(899, 1)
+  assert_rational Rational(-2, 9) - Rational(-9, 2), Rational(77, 18)
+  assert_rational Rational(9, 8)  - 4,               Rational(-23, 8)
+  assert_float    Rational(20, 9) - 9.8,             -7.577777777777778
+end
+
+assert 'Rational#/' do
+  assert_rational Rational(2, 3)  / Rational(2, 3),  Rational(1, 1)
+  assert_rational Rational(900)   / Rational(1),     Rational(900, 1)
+  assert_rational Rational(-2, 9) / Rational(-9, 2), Rational(4, 81)
+  assert_rational Rational(9, 8)  / 4,               Rational(9, 32)
+  assert_float    Rational(20, 9) / 9.8,             0.22675736961451246
 end
\ No newline at end of file