From 924cb525f587c58440c43bcae6ccfd9b2e41c99c Mon Sep 17 00:00:00 2001
From: David Gow <david@ingeniumdigital.com>
Date: Sun, 6 Jul 2014 21:51:10 +0800
Subject: [PATCH] Rational<Arbint> now passes realops.test

---
 src/arbint.cpp |  5 +++++
 src/arbint.h   | 21 +++++++++++++++++++--
 src/rational.h | 11 +++++++++--
 3 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/src/arbint.cpp b/src/arbint.cpp
index 4bde578..ac39942 100644
--- a/src/arbint.cpp
+++ b/src/arbint.cpp
@@ -114,6 +114,11 @@ void Arbint::Division(const Arbint & div, Arbint & result, Arbint & remainder) c
 {
 	remainder = 0;
 	result = 0;
+	if (div.IsZero())
+	{
+		result = *this;
+		return;
+	}
 	for (int i = 8*sizeof(digit_t)*m_digits.size(); i >= 0; --i)
 	{
 		remainder <<= 1;
diff --git a/src/arbint.h b/src/arbint.h
index 0f047c9..06008e0 100644
--- a/src/arbint.h
+++ b/src/arbint.h
@@ -23,7 +23,7 @@ namespace IPDF
 			virtual ~Arbint() {}
 			Arbint(const Arbint & cpy);
 			
-			int64_t AsDigit() const 
+			int64_t AsDigit() const
 			{
 				int64_t digit = (m_digits.size() == 1) ? m_digits[0] : 0x7FFFFFFFFFFFFFFF;
 				return (m_sign) ? -digit : digit;
@@ -60,6 +60,13 @@ namespace IPDF
 				a -= add;
 				return a;
 			}
+
+			inline Arbint operator-()
+			{
+				Arbint a(*this);
+				a.m_sign = !a.m_sign;
+				return a;
+			}
 			
 			inline Arbint operator*(const Arbint & mul) const
 			{
@@ -124,7 +131,17 @@ namespace IPDF
 			}
 			bool IsZero() const;
 			
-			//inline operator double() const {return double(AsDigit());}
+			inline operator double() const 
+			{
+				double acc = 0;
+				for(int i = m_digits.size()-1; i >= 0; --i)
+				{
+					acc += (double)m_digits[i];
+					acc *= (double)UINT64_MAX + 1.0;
+				}
+				if (m_sign) acc *= -1;
+				return acc;
+			}
 			inline operator int64_t() const {return AsDigit();}
 			//inline operator int() const {return int(AsDigit());}
 			
diff --git a/src/rational.h b/src/rational.h
index 53f7d02..2c98e1a 100644
--- a/src/rational.h
+++ b/src/rational.h
@@ -15,9 +15,10 @@ namespace IPDF
 	
 template <class T> T Tabs(const T & a)
 {
-	return llabs(a);
+	return abs(a);
 }
 
+template <> Arbint Tabs(const Arbint & a);
 
 
 /* Recursive version  of GCD
@@ -97,6 +98,12 @@ struct Rational
 			Q = T(1);
 			return;
 		}
+		if (P == Q)
+		{
+			P = Q = T(1);
+			return;
+		}
+		
 		T g = gcd(Tabs(P), Tabs(Q));
 		//Debug("Got gcd!");
 		P /= g;
@@ -156,7 +163,7 @@ struct Rational
 	//Rational operator*(const Rational & r) const {return Rational(ToDouble()*r.ToDouble());}
 	//Rational operator/(const Rational & r) const {return Rational(ToDouble()/r.ToDouble());}
 
-	Rational & operator=(const Rational & r) {P = r.P; Q = r.Q; return *this;}
+	Rational & operator=(const Rational & r) {P = r.P; Q = r.Q; Simplify(); return *this;}
 	Rational & operator+=(const Rational & r) {this->operator=(*this+r); return *this;}
 	Rational & operator-=(const Rational & r) {this->operator=(*this-r); return *this;}
 	Rational & operator*=(const Rational & r) {this->operator=(*this*r); return *this;}
-- 
2.20.1