/*
- rational.cc -- implement Rational
+ This file is part of LilyPond, the GNU music typesetter.
- source file of the Flower Library
+ Copyright (C) 1997--2015 Han-Wen Nienhuys <hanwen@xs4all.nl>
- (c) 1997--2005 Han-Wen Nienhuys <hanwen@cs.uu.nl>
+ LilyPond is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ LilyPond is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with LilyPond. If not, see <http://www.gnu.org/licenses/>.
*/
#include "rational.hh"
#include <cmath>
+#include <cassert>
#include <cstdlib>
using namespace std;
#include "string-convert.hh"
#include "libc-extension.hh"
-Rational::operator double () const
+double
+Rational::to_double () const
{
- return ((double)sign_) * num_ / den_;
-}
+ if (sign_ == -1 || sign_ == 1 || sign_ == 0)
+ return (double)sign_ * (double)num_ / (double)den_;
+ if (sign_ == -2)
+ return -HUGE_VAL;
+ else if (sign_ == 2)
+ return HUGE_VAL;
+ else
+ assert (false);
-Rational::operator bool () const
-{
- return sign_ && num_;
+ return 0.0;
}
#ifdef STREAM_SUPPORT
}
#endif
+Rational
+Rational::abs () const
+{
+ return Rational (num_, den_);
+}
+
Rational
Rational::trunc_rat () const
{
- return Rational (num_ - (num_ % den_), den_);
+ if (is_infinity ())
+ return *this;
+ return Rational ((num_ - (num_ % den_)) * sign_, den_);
}
Rational::Rational ()
num_ = den_ = 1;
}
-Rational::Rational (int n, int d)
+Rational::Rational (I64 n, I64 d)
{
sign_ = ::sign (n) * ::sign (d);
- num_ = abs (n);
- den_ = abs (d);
- normalise ();
+ num_ = ::abs (n);
+ den_ = ::abs (d);
+ normalize ();
}
-Rational::Rational (int n)
+Rational::Rational (I64 n)
{
sign_ = ::sign (n);
- num_ = abs (n);
+ num_ = ::abs (n);
den_ = 1;
}
-static inline
-int gcd (int a, int b)
+Rational::Rational (U64 n)
{
- int t;
- while ((t = a % b))
- {
- a = b;
- b = t;
- }
- return b;
+ sign_ = 1;
+ num_ = n;
+ den_ = 1;
+}
+
+Rational::Rational (int n)
+{
+ sign_ = ::sign (n);
+ num_ = ::abs (n);
+ den_ = 1;
}
void
Rational::set_infinite (int s)
{
sign_ = ::sign (s) * 2;
+ num_ = 1;
}
Rational
return r;
}
+/*
+ copy & paste from scm_gcd (GUILE).
+ */
+static I64
+gcd (I64 u, I64 v)
+{
+ I64 result = 0;
+ if (u == 0)
+ result = v;
+ else if (v == 0)
+ result = u;
+ else
+ {
+ I64 k = 1;
+ I64 t;
+ /* Determine a common factor 2^k */
+ while (!(1 & (u | v)))
+ {
+ k <<= 1;
+ u >>= 1;
+ v >>= 1;
+ }
+ /* Now, any factor 2^n can be eliminated */
+ if (u & 1)
+ t = -v;
+ else
+ {
+ t = u;
+b3:
+ t = t >> 1;
+ }
+ if (!(1 & t))
+ goto b3;
+ if (t > 0)
+ u = t;
+ else
+ v = -t;
+ t = u - v;
+ if (t != 0)
+ goto b3;
+ result = u * k;
+ }
+
+ return result;
+}
+
void
-Rational::normalise ()
+Rational::normalize ()
{
if (!sign_)
{
}
else
{
- int g = gcd (num_, den_);
+ I64 g = gcd (num_, den_);
num_ /= g;
den_ /= g;
return -1;
else if (r.sign_ > s.sign_)
return 1;
- else if (r.is_infinity ())
+ else if (r.is_infinity ()) // here s is also infinite with the same sign
return 0;
- else if (r.sign_ == 0)
+ else if (r.sign_ == 0) // here s.sign_ is also zero
return 0;
- return r.sign_ * ::sign (int (r.num_ * s.den_) - int (s.num_ * r.den_));
+ return ::sign (r - s);
}
int
*this = r;
else
{
- 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;
+ I64 lcm = (den_ / gcd (r.den_, den_)) * r.den_;
+ I64 n = sign_ * num_ * (lcm / den_) + r.sign_ * r.num_ * (lcm / r.den_);
+ I64 d = lcm;
sign_ = ::sign (n) * ::sign (d);
- num_ = abs (n);
- den_ = abs (d);
- normalise ();
+ num_ = ::abs (n);
+ den_ = ::abs (d);
+ normalize ();
}
return *this;
}
const int FACT = 1 << 20;
/*
- Thanks to Afie for this too simple idea.
+ Thanks to Afie for this too simple idea.
- do not blindly substitute by libg++ code, since that uses
- arbitrary-size integers. The rationals would overflow too
- easily.
+ do not blindly substitute by libg++ code, since that uses
+ arbitrary-size integers. The rationals would overflow too
+ easily.
*/
- num_ = (unsigned int) (mantissa * FACT);
- den_ = (unsigned int) FACT;
- normalise ();
+ num_ = (U64) (mantissa * FACT);
+ den_ = (U64) FACT;
+ normalize ();
if (expt < 0)
- den_ <<= -expt;
+ den_ <<= -expt;
else
- num_ <<= expt;
- normalise ();
+ num_ <<= expt;
+ normalize ();
}
else
{
num_ = 0;
den_ = 1;
sign_ = 0;
- normalise ();
+ normalize ();
}
}
void
Rational::invert ()
{
- int r (num_);
+ I64 r (num_);
num_ = den_;
den_ = r;
}
num_ *= r.num_;
den_ *= r.den_;
- normalise ();
- exit_func:
+ normalize ();
+exit_func:
return *this;
}
return (*this += r);
}
-String
+string
Rational::to_string () const
{
if (is_infinity ())
{
- String s (sign_ > 0 ? "" : "-");
- return String (s + "infinity");
+ string s (sign_ > 0 ? "" : "-");
+ return string (s + "infinity");
}
- String s = ::to_string (num ());
+ string s = ::to_string (num ());
if (den () != 1 && num ())
s += "/" + ::to_string (den ());
return s;
int
Rational::to_int () const
{
- return (int) num () / den ();
+ return (int) (num () / den ());
}
int
projects / lilypond.git / blobdiff