/*
 * Copyright (C) 2007-2008 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 (First Edition, Version 6)
 * by Martin Odersky, Lex Spoon, Bill Venners
 *
 * http://booksites.artima.com/programming_in_scala
 */


scala> var increase = (x: Int) => x + 1
increase: (Int) => Int = <function>

scala> increase(10)
res0: Int = 11

scala> increase = (x: Int) => x + 9999
increase: (Int) => Int = <function>

scala> increase(10)
res2: Int = 10009

scala> increase = (x: Int) => {
         println("We")
         println("are")
         println("here!")
         x + 1
       }
increase: (Int) => Int = <function>

scala> increase(10)
We
are
here!
res4: Int = 11

scala> val someNumbers = List(-11, -10, -5, 0, 5, 10)
someNumbers: List[Int] = List(-11, -10, -5, 0, 5, 10)

scala> someNumbers.foreach((x: Int) => println(x))
-11
-10
-5
0
5
10

scala> someNumbers.filter((x: Int) => x > 0)
res6: List[Int] = List(5, 10)

scala> someNumbers.filter((x) => x > 0)
res7: List[Int] = List(5, 10)

scala> someNumbers.filter(x => x > 0)
res8: List[Int] = List(5, 10)

scala> someNumbers.filter(_ > 0)
res9: List[Int] = List(5, 10)

scala> someNumbers.filter(x => x > 0)
res10: List[Int] = List(5, 10)

scala> val f = _ + _
<console>:4: error: missing parameter type for expanded function ((x$1, x$2) => x$1.$plus(x$2))
       val f = _ + _
               ^
<console>:4: error: missing parameter type for expanded function ((x$1: <error>, x$2) => x$1.$plus(x$2))
       val f = _ + _
                   ^

scala> val f = (_: Int) + (_: Int)
f: (Int, Int) => Int = <function>

scala> f(5, 10)
res11: Int = 15

scala> def sum(a: Int, b: Int, c: Int) = a + b + c
sum: (Int,Int,Int)Int

scala> sum(1, 2, 3)
res12: Int = 6

scala> val a = sum _
a: (Int, Int, Int) => Int = <function>

scala> a(1, 2, 3)
res13: Int = 6

scala> a.apply(1, 2, 3)
res14: Int = 6

scala> val b = sum(1, _: Int, 3)
b: (Int) => Int = <function>

scala> b(2)
res15: Int = 6

scala> b(5)
res16: Int = 9

scala> val c = sum
<console>:5: error: missing arguments for method sum in object $iw;
follow this method with `_' if you want to treat it as a partially applied function
       val c = sum
               ^

scala> val d = sum _
d: (Int, Int, Int) => Int = <function>

scala> d(10, 20, 30)
res17: Int = 60

scala> (x: Int) => x + more
<console>:5: error: not found: value more
       (x: Int) => x + more
                       ^

scala> var more = 1
more: Int = 1

scala> val addMore = (x: Int) => x + more
addMore: (Int) => Int = <function>

scala> addMore(10)
res19: Int = 11

scala> more = 9999
more: Int = 9999

scala> addMore(10)
res21: Int = 10009

scala> val someNumbers = List(-11, -10, -5, 0, 5, 10)
someNumbers: List[Int] = List(-11, -10, -5, 0, 5, 10)

scala> var sum = 0
sum: Int = 0

scala> someNumbers.foreach(sum +=  _)

scala> sum
res23: Int = -11

scala>   def makeIncreaser(more: Int) = (x: Int) => x + more

makeIncreaser: (Int)(Int) => Int

scala> val inc1 = makeIncreaser(1)
inc1: (Int) => Int = <function>

scala> val inc9999 = makeIncreaser(9999)
inc9999: (Int) => Int = <function>

scala> inc1(10)
res24: Int = 11

scala> inc9999(10)
res25: Int = 10009

scala> def echo(args: String*) = 
         for (arg <- args) println(arg)
echo: (String*)Unit

scala> echo()

scala> echo("one")
one

scala> echo("hello", "world!")
hello
world!

scala> val arr = Array("What's", "up", "doc?")
arr: Array[java.lang.String] = Array(What's, up, doc?)

scala> echo(arr)
<console>:7: error: type mismatch;
 found   : Array[java.lang.String]
 required: String
       echo(arr)
            ^

scala> echo(arr: _*)
What's
up
doc?

scala>   def boom(x: Int): Int = 
           if (x == 0) throw new Exception("boom!")
           else boom(x - 1) + 1

boom: (Int)Int

scala>  def bang(x: Int): Int = 
          if (x == 0) throw new Exception("bang!")
          else bang(x - 1)

bang: (Int)Int