/*
 * Copyright (C) 2007-2020 Artima, Inc. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Automatically generated Scala interpreter transcript from:
 *
 * Programming in Scala (Fifth Edition)
 * by Martin Odersky, Lex Spoon, Bill Venners, and Frank Sommers
 *
 * http://booksites.artima.com/programming_in_scala_5ed
 */


scala> class Queue[T](elems: List[T]) {
         def head = elems.head
         def tail = elems.tail
         def enqueue(x: T) = new Queue(elems ::: List(x))
         override def toString() = elems.mkString("Queue(", ", ", ")")
       }
defined class Queue

scala> def Queue[T](elems: T*) = new Queue(elems.toList)
Queue: [T](elems: T*)Queue[T]

scala>   class Queue[T] private (
           private val leading: List[T],
           private val trailing: List[T]
         ) 

defined class Queue

scala> Queue(List(1, 2), List(3))
res0: Queue[List[Int]] = Queue(List(1, 2), List(3))

scala> def doesNotCompile(q: Queue) = {}
                             ^
       error: class Queue takes type parameters

scala> def doesCompile(q: Queue[AnyRef]) = {}
doesCompile: (q: Queue[AnyRef])Unit

scala> val a1 = Array("abc")
a1: Array[String] = Array(abc)

scala> val a2: Array[Any] = a1
                            ^
       error: type mismatch;
        found   : Array[String]
        required: Array[Any]
       Note: String <: Any, but class Array is invariant in type T.
       You may wish to investigate a wildcard type such as `_ <: Any`. (SLS 3.2.10)