diff options
Diffstat (limited to 'Scala/sandbox/5-intlist.scala')
-rw-r--r-- | Scala/sandbox/5-intlist.scala | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/Scala/sandbox/5-intlist.scala b/Scala/sandbox/5-intlist.scala new file mode 100644 index 0000000..6b29401 --- /dev/null +++ b/Scala/sandbox/5-intlist.scala @@ -0,0 +1,35 @@ + +object IntList { + + trait List [T] { + def isEmpty: Boolean + def head: T + def tail: List[T] + def nth(n: Int): T + } + + class Cons[T](val head: T, val tail: List[T]) extends List[T] { + def isEmpty = false + def nth(n: Int): T = { + if (isEmpty) throw new IndexOutOfBoundsException + if (n==0) head + else tail nth(n - 1) + } + } + + class Nil[T] extends List[T] { + def isEmpty: Boolean = true + def head: Nothing = throw new NoSuchElementException("Nil.head") + def tail: Nothing = throw new NoSuchElementException("Nil.tail") + def nth(n: Int): Nothing = throw new NoSuchElementException("Nil.nth") + } + + + def run = { + println("IntList") + val list = new Cons(1, new Cons(2, new Cons(3, new Nil))) + println(list nth 2) + println(list nth 0) + /* println(list nth 5) */ + } +} |