release: 0.0.17

[lilypond.git] / flower / interval.hh

diff --git a/flower/interval.hh b/flower/interval.hh
index a7a269153bf42ba9e34502011909dd0358a27bd4..4184451701e72aa11ccf8a6ea015d7b64317ae76 100644 (file)
--- a/flower/interval.hh
+++ b/flower/interval.hh
@@ -12,57 +12,103 @@
 #include "real.hh"
 
 
-/// a Real interval
-struct Interval {
-    Real min, max;
+/// a T interval
+template<class T>
+struct Interval_t {
+    T left, right;
 
-    void translate(Real t) {
-       min += t;
-       max += t;
+    /****************/
+    
+    T center() { return (left + right) /2;}
+    void translate(T t) {
+       left += t;
+       right += t;
     }
-    Real operator[](int j) {
+    T operator[](int j) {
        if (j==-1)
-           return min;
+           return left;
        else if (j==1)
-           return max;
+           return right;
        else
            assert(false);
-           return 0.0;
-               
+       return 0;               
     }
-    void unite(Interval h) ;
-    void intersect(Interval h);
+    void unite(Interval_t<T> h);
+    /**
+      PRE
+      *this and h are comparable
+      */
+    void intersect(Interval_t<T> h);
 
-    Real length() const;
+    T length() const;
     void set_empty() ;
-    bool empty() const { return min > max; }
-    Interval() {
+    bool empty() const { return left > right; }
+    Interval_t() {
        set_empty();
     }
-    Interval(Real m, Real M) {
-       min =m;
-       max = M;
+    Interval_t(T m, T M) {
+       left =m;
+       right = M;
     }
-    Interval &operator += (Real r) {
-       min += r;
-       max +=r;
+    Interval_t<T> &operator += (T r) {
+       left += r;
+       right +=r;
        return *this;
     }
-    bool elt_q(Real r);
-    operator String() const;
-
-    /// partial ordering
-    static compare(const Interval&,Interval const&);
+    String str() const;    
+    bool elt_q(T r);
 };
 /**
-  this represents the closed interval [min,max]
+  this represents the closed interval [left,right].
+  No invariants. T must be a totally ordered ring
+  */
+
+/// partial ordering
+template<class T>
+int Interval__compare(const Interval_t<T>&,Interval_t<T> const&);
+/**
+  inclusion ordering. Crash if not comparable.
   */
 
-Interval intersection(Interval, Interval const&);
+/****************************************************************
+  INLINE
+ ****************************************************************/
 
 #include "compare.hh"
 
-instantiate_compare(Interval&, Interval::compare);
+template_instantiate_compare(Interval_t<T>&, Interval__compare, template<class T>);
+
+
+template<class T>
+inline Interval_t<T>
+intersection(Interval_t<T> a, Interval_t<T> const&b)
+{
+    a.intersect(b);
+    return a;
+    
+}
+
+
+template<class T>
+inline
+Interval_t<T> operator +(T a,Interval_t<T> i )
+{
+    i += a;
+    return i;
+}
+
+template<class T>
+inline
+Interval_t<T> operator +(Interval_t<T> i,T a ){
+    return a+i;
+}
+
+typedef Interval_t<Real> Interval;
+
+
+#define Interval__instantiate(T) template struct Interval_t<T>;\
+  template  int Interval__compare(const Interval_t<T>&,Interval_t<T> const&)
+
 
 #endif // INTERVAL_HH