Update documentation

README.md

@@ -17,41 +17,31 @@ go get github.com/francesconi/go-rampart
 ## Examples
 
 ```go
-a := rampart.NewOrdInterval(2, 3)
-b := rampart.NewOrdInterval(3, 7)
+a := rampart.NewInterval(2, 3)
+b := rampart.NewInterval(3, 7)
 rel := a.Relate(b)
 // rel: RelationMeets
 ```
 
 ```go
-a := rampart.NewTimeInterval(
+func compareTimes(t1, t2 time.Time) int {
+    return int(t1.Sub(t2))
+}
+
+a := rampart.NewIntervalFunc(
     time.Date(2022, time.April, 1, 0, 0, 0, 0, time.UTC),
     time.Date(2022, time.April, 8, 0, 0, 0, 0, time.UTC),
+    compareTimes,
 )
-b := rampart.NewTimeInterval(
+b := rampart.NewIntervalFunc(
     time.Date(2022, time.April, 6, 0, 0, 0, 0, time.UTC),
     time.Date(2022, time.April, 15, 0, 0, 0, 0, time.UTC),
+    compareTimes,
 )
 rel := a.Relate(b)
 // rel: RelationOverlaps
 ```
 
-```go
-func cmp(x, y int) int {
-    if x < y {
-        return -1
-    }
-    if x == y {
-        return 0
-    }
-    return 1
-}
-a := rampart.NewIntervalFunc(2, 3, cmp)
-b := rampart.NewIntervalFunc(3, 7, cmp)
-rel := a.Relate(b)
-// rel: RelationMeets
-```
-
 ![][interval relations]
 
 [interval relations]: ./docs/interval-relations.svg

rampart.go

@@ -5,7 +5,7 @@ import (
 )
 
 // Interval represents two values, the lesser and the greater.
-// Both must be either of the same ordered type or time type.
+// Both must be of the same type.
 type Interval[T any] struct {
 	x, y T
 	cmp  func(T, T) int

rampart_test.go

@@ -10,7 +10,7 @@ import (
 func TestTimeInterval(t *testing.T) {
 	now := time.Now()
 	a := NewIntervalFunc(now.Add(1000), now, func(t1, t2 time.Time) int { return int(t1.Sub(t2)) })
-	require.Equal(t, a.Lesser(), now)
+	require.Equal(t, now, a.Lesser())
 }
 
 func TestNewInterval(t *testing.T) {