source file of the Flower Library
- (c) 1997 Han-Wen Nienhuys <hanwen@stack.nl>
+ (c) 1997--1998 Han-Wen Nienhuys <hanwen@cs.uu.nl>
*/
#include <stdlib.h>
#include "rational.hh"
#include "string-convert.hh"
#include "libc-extension.hh"
-
Rational::operator bool () const
{
return sign_;
}
+Rational::operator int () const
+{
+ return sign_ * num_ / den_;
+}
+
+Rational::operator double () const
+{
+ return (double)sign_ * num_ / den_;
+}
+
ostream &
operator << (ostream &o, Rational r)
{
return o;
}
-
-
Rational
Rational::truncated () const
{
*/
Rational::Rational(double x)
{
- num_ = 0;
- den_ = 1;
if (x != 0.0)
{
sign_ = ::sign (x);
x *= sign_;
- const long shift = 15; // a safe shift per step
- const double width = 32768.0; // = 2^shift
- const int maxiter = 20; // ought not be necessary, but just in case,
- // max 300 bits of precision
int expt;
double mantissa = frexp(x, &expt);
- long exponent = expt;
- double intpart;
- int k = 0;
- while (mantissa != 0.0 && k++ < maxiter)
- {
- mantissa *= width;
- mantissa = modf(mantissa, &intpart);
- num_ <<= shift;
- num_ += (long)intpart;
- exponent -= shift;
- }
- if (exponent > 0)
- num_ <<= exponent;
- else if (exponent < 0)
- den_ <<= -exponent;
- } else {
- sign_ = 0;
+
+ const int FACT = 1 << 20;
+
+ /*
+ FIXME
+
+ SHOULD TEST THIS
+
+ suck me gently with a vacuum cleaner. Thanks to Afie for this wierd idea.
+ */
+ num_ = (unsigned int) (mantissa * FACT);
+ den_ = (unsigned int) FACT;
+ normalise ();
+ num_ <<= expt;
+ }
+ else
+ {
+ num_ = 0;
+ den_ = 1;
+ sign_ =0;
+ normalise ();
}
- normalise();
}
copy (r);
}
-Rational::operator String () const
-{
- return str ();
-}
-
String
Rational::str () const
{
String s (sign_ > 0 ? "" : "-" );
return String (s + "infinity");
}
- String s (num ());
+ String s = to_str (num ());
if (den () != 1 && num ())
- s += "/" + String (den ());
+ s += "/" + to_str (den ());
return s;
}