source file of the Flower Library
- (c) 1997--2006 Han-Wen Nienhuys <hanwen@xs4all.nl>
+ (c) 1997--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
*/
#include "rational.hh"
#include "string-convert.hh"
#include "libc-extension.hh"
-Rational::operator double () const
+double
+Rational::to_double () const
{
if (sign_ == -1 || sign_ == 1 || sign_ == 0)
return ((double)sign_) * num_ / den_;
return 0.0;
}
-Rational::operator bool () const
-{
- return sign_ && num_;
-}
#ifdef STREAM_SUPPORT
ostream &
}
#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 ()
Rational::Rational (int n, int d)
{
sign_ = ::sign (n) * ::sign (d);
- num_ = abs (n);
- den_ = abs (d);
- normalise ();
+ num_ = ::abs (n);
+ den_ = ::abs (d);
+ normalize ();
}
Rational::Rational (int n)
{
sign_ = ::sign (n);
- num_ = abs (n);
+ num_ = ::abs (n);
den_ = 1;
}
-static inline
-int gcd (int a, int b)
-{
- int t;
- while ((t = a % b))
- {
- a = b;
- b = t;
- }
- return b;
-}
void
Rational::set_infinite (int s)
{
sign_ = ::sign (s) * 2;
+ num_ = 1;
}
Rational
return r;
}
+
+/*
+ copy & paste from scm_gcd (GUILE).
+ */
+static int
+gcd (long u, long v)
+{
+ long result = 0;
+ if (u == 0)
+ result = v;
+ else if (v == 0)
+ result = u;
+ else
+ {
+ long k = 1;
+ long 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_)
{
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 ();
+ num_ = ::abs (n);
+ den_ = ::abs (d);
+ normalize ();
}
return *this;
}
num_ = (unsigned int) (mantissa * FACT);
den_ = (unsigned int) FACT;
- normalise ();
+ normalize ();
if (expt < 0)
den_ <<= -expt;
else
num_ <<= expt;
- normalise ();
+ normalize ();
}
else
{
num_ = 0;
den_ = 1;
sign_ = 0;
- normalise ();
+ normalize ();
}
}
num_ *= r.num_;
den_ *= r.den_;
- normalise ();
+ normalize ();
exit_func:
return *this;
}