* The grand 2005-2006 replace.

[lilypond.git] / flower / rational.cc

diff --git a/flower/rational.cc b/flower/rational.cc
index c5019afbd5a5d1fa6563a461e024ced7df70d21c..b61c84e014a78922a17bcb6f33ce59f1b71786f9 100644 (file)
--- a/flower/rational.cc
+++ b/flower/rational.cc
@@ -1,32 +1,39 @@
 /*
   rational.cc -- implement Rational
-  
+
   source file of the Flower Library
 
-  (c)  1997--2003 Han-Wen Nienhuys <hanwen@cs.uu.nl>
+  (c) 1997--2006 Han-Wen Nienhuys <hanwen@xs4all.nl>
 */
-#include <math.h>
-#include <stdlib.h>
+
 #include "rational.hh"
-#include "string.hh"
-#include "string-convert.hh"  
+
+#include <cmath>
+#include <cstdlib>
+using namespace std;
+
+#include "string-convert.hh"
 #include "libc-extension.hh"
 
 Rational::operator double () const
 {
-  return (double)sign_ * num_ / den_;
+  return ((double)sign_) * num_ / den_;
+}
+
+Rational::operator bool () const
+{
+  return sign_ && num_;
 }
 
 #ifdef STREAM_SUPPORT
 ostream &
 operator << (ostream &o, Rational r)
 {
-  o <<  r.string ();
+  o << r.string ();
   return o;
 }
 #endif
 
-
 Rational
 Rational::trunc_rat () const
 {
@@ -51,10 +58,10 @@ Rational::Rational (int n)
 {
   sign_ = ::sign (n);
   num_ = abs (n);
-  den_= 1;
+  den_ = 1;
 }
 
-static
+static inline
 int gcd (int a, int b)
 {
   int t;
@@ -66,18 +73,10 @@ int gcd (int a, int b)
   return b;
 }
 
-#if 0
-static
-int lcm (int a, int b)
-{
-  return abs (a*b / gcd (a,b));
-}
-#endif
-
 void
 Rational::set_infinite (int s)
 {
-  sign_ = ::sign (s) * 2; 
+  sign_ = ::sign (s) * 2;
 }
 
 Rational
@@ -124,7 +123,7 @@ Rational::normalise ()
     }
   else
     {
-      int g = gcd (num_ , den_);
+      int g = gcd (num_, den_);
 
       num_ /= g;
       den_ /= g;
@@ -143,54 +142,49 @@ Rational::compare (Rational const &r, Rational const &s)
     return -1;
   else if (r.sign_ > s.sign_)
     return 1;
-  else if (r.infty_b ())
+  else if (r.is_infinity ())
     return 0;
   else if (r.sign_ == 0)
     return 0;
-  else
-    {
-      return r.sign_ * ::sign  (int (r.num_ * s.den_) - int (s.num_ * r.den_));
-    }
+  return r.sign_ * ::sign (int (r.num_ * s.den_) - int (s.num_ * r.den_));
 }
 
 int
 compare (Rational const &r, Rational const &s)
 {
-  return Rational::compare (r, s );
+  return Rational::compare (r, s);
 }
 
 Rational &
 Rational::operator %= (Rational r)
 {
-  *this = r.mod_rat (r);
+  *this = mod_rat (r);
   return *this;
 }
 
 Rational &
 Rational::operator += (Rational r)
 {
-  if (infty_b ())
+  if (is_infinity ())
     ;
-  else if (r.infty_b ())
-    {
-      *this = r;
-    }
-  else 
+  else if (r.is_infinity ())
+    *this = r;
+  else
     {
-      int n = sign_ * num_ *r.den_ + r.sign_ * den_ * r.num_;
-      int d = den_ * r.den_;
-      sign_ =  ::sign (n) * ::sign (d);
+      int lcm = (den_ / gcd (r.den_, den_)) * r.den_;
+      int n = sign_ * num_ * (lcm / den_) + r.sign_ * r.num_ * (lcm / r.den_);
+      int d = lcm;
+      sign_ = ::sign (n) * ::sign (d);
       num_ = abs (n);
       den_ = abs (d);
       normalise ();
     }
   return *this;
 }
-    
 
 /*
   copied from libg++ 2.8.0
- */ 
+*/
 Rational::Rational (double x)
 {
   if (x != 0.0)
@@ -213,7 +207,7 @@ Rational::Rational (double x)
 
       num_ = (unsigned int) (mantissa * FACT);
       den_ = (unsigned int) FACT;
-      normalise ();      
+      normalise ();
       if (expt < 0)
        den_ <<= -expt;
       else
@@ -224,17 +218,16 @@ Rational::Rational (double x)
     {
       num_ = 0;
       den_ = 1;
-      sign_ =0;
+      sign_ = 0;
       normalise ();
     }
 }
 
-
 void
 Rational::invert ()
 {
   int r (num_);
-  num_  = den_;
+  num_ = den_;
   den_ = r;
 }
 
@@ -242,8 +235,8 @@ Rational &
 Rational::operator *= (Rational r)
 {
   sign_ *= ::sign (r.sign_);
-  if (r.infty_b ())
-    {  
+  if (r.is_infinity ())
+    {
       sign_ = sign () * 2;
       goto exit_func;
     }
@@ -255,7 +248,7 @@ Rational::operator *= (Rational r)
  exit_func:
   return *this;
 }
-  
+
 Rational &
 Rational::operator /= (Rational r)
 {
@@ -269,7 +262,7 @@ Rational::negate ()
   sign_ *= -1;
 }
 
-Rational&
+Rational &
 Rational::operator -= (Rational r)
 {
   r.negate ();
@@ -279,9 +272,9 @@ Rational::operator -= (Rational r)
 String
 Rational::to_string () const
 {
-  if (infty_b ())
+  if (is_infinity ())
     {
-      String s (sign_ > 0 ? "" : "-" );
+      String s (sign_ > 0 ? "" : "-");
       return String (s + "infinity");
     }
 
@@ -294,7 +287,7 @@ Rational::to_string () const
 int
 Rational::to_int () const
 {
-  return num () / den ();
+  return (int) num () / den ();
 }
 
 int
@@ -302,3 +295,9 @@ sign (Rational r)
 {
   return r.sign ();
 }
+
+bool
+Rational::is_infinity () const
+{
+  return sign_ == 2 || sign_ == -2;
+}