2 interval.hh -- part of flowerlib
4 (c) 1996 Han-Wen Nienhuys
11 #include "flower-proto.hh"
13 #include "drul-array.hh"
15 /** a T interval. this represents the closed interval [left,right].
16 No invariants. T must be a totally ordered ring (with division, anyway ..)
17 At instantiation, the function infinity () has to be defined explicitely.
21 struct Interval_t : public Drul_array<T> {
25 static T infinity () ;
26 static String T_to_str (T arg);
29 return (elem (LEFT) + elem (RIGHT)) / T (2);
39 *this and h are comparable
41 void unite (Interval_t<T> h);
42 void intersect (Interval_t<T> h);
46 bool empty_b () const { return elem (LEFT) > elem (RIGHT); }
47 bool contains_b (Interval_t<T> const&) const;
51 Interval_t (T m, T M) : Drul_array<T> (m,M)
53 Interval_t<T> &operator -= (T r) {
58 Interval_t<T> &operator += (T r) {
63 Interval_t<T> &operator *= (T r) {
70 elem (LEFT) = elem (RIGHT);
77 Real linear_combination (Real x) const {
78 return ((1.0 - x) * Real (elem (LEFT)) + (x + 1.0) * Real (elem (RIGHT))) * 0.5;
93 inclusion ordering. Crash if not comparable.
96 int Interval__compare (const Interval_t<T>&,Interval_t<T> const&);
99 Inclusion ordering. return -2 if not comparable
103 _Interval__compare (const Interval_t<T>&a,Interval_t<T> const&b);
110 #include "compare.hh"
112 TEMPLATE_INSTANTIATE_COMPARE (Interval_t<T>&, Interval__compare, template<class T>);
117 intersection (Interval_t<T> a, Interval_t<T> const&b)
126 Interval_t<T> operator + (T a,Interval_t<T> i)
134 Interval_t<T> operator - (Interval_t<T> i, T a)
142 Interval_t<T> operator - (T a,Interval_t<T> i)
151 Interval_t<T> operator + (Interval_t<T> i,T a){
157 Interval_t<T> operator * (T a,Interval_t<T> i)
165 Interval_t<T> operator * (Interval_t<T> i,T a){
169 // again? see flower-proto.hh
170 typedef Interval_t<Real> Interval;
171 typedef Interval_t<int> Slice; // weird name
174 #endif // INTERVAL_HH