Added ComparableRange.

libraries/stdlib/src/kotlin/Ranges.kt

@@ -1,5 +1,24 @@
 package kotlin
 
+public data class ComparableRange<T: Comparable<T>> (
+        public override val start: T,
+        public override val end: T
+): Range<T> {
+    public override fun contains(item: T): Boolean {
+        return start <= item && item <= end
+    }
+
+    public fun toString(): String {
+        return "$start..$end"
+    }
+}
+
+public fun <T: Comparable<T>> T.rangeTo(that: T): ComparableRange<T> {
+    return ComparableRange(this, that)
+}
+
+
+
 public fun CharacterSequence.reversed(): CharacterSequence {
     return CharacterSequence(end, start, -increment)
 }

libraries/stdlib/test/language/RangeTest.kt

@@ -35,4 +35,17 @@ class RangeTest {
         assertEquals(0.0, reversedDoubleRange.end)
         assertEquals(doubleRange.toList(), reversedDoubleRange.reversed().toList())
     }
+
+    test fun comparableRange() {
+        val range1 = "island".."isle"
+        assertTrue("island" in range1)
+        assertTrue("isle" in range1)
+        assertTrue("islandic" in range1)
+
+        assertFalse("apple" in range1)
+        assertFalse("icicle" in range1)
+
+        assertFalse("item" in range1)
+        assertFalse("trail" in range1)
+    }
 }