環境
Mac OS X 10.9.1
Scala version 2.10.3
概要
カリー化とは、複数のパラメータをとる関数を1つのパラメータをとる関数のチェーンに変換すること。
コード
scala> def sum(a:Int, b:Int, c:Int) = a + b + c sum: (a: Int, b: Int, c: Int)Int scala> val fObj = sum _ fObj: (Int, Int, Int) => Int = <function3> scala> fObj(1,2,3) res0: Int = 6 scala> val fObj2 = sum (_:Int, 2, 3) // 部分適用 fObj2: Int => Int = <function1> scala> fObj2(1) res1: Int = 6 scala> def sum(a:Int)(b:Int)(c:Int) = a + b + c // カリー化 sum: (a: Int)(b: Int)(c: Int)Int scala> def sumCurry(a:Int) = (b:Int) => (c:Int) => a + b + c sumCurry: (a: Int)Int => (Int => Int) scala> val fObj1 = sumCurry(1) fObj1: Int => (Int => Int) = <function1> scala> val fObj2 = fObj1(2) fObj2: Int => Int = <function1> scala> fObj2(3) res2: Int = 6 scala> def sum(a:Int, b:Int, c:Int) = a + b + c sum: (a: Int, b: Int, c: Int)Int scala> val currySum = (sum _).curried currySum: Int => (Int => (Int => Int)) = <function1> scala> currySum(1) res3: Int => (Int => Int) = <function1> scala> currySum(2) res4: Int => (Int => Int) = <function1> scala> currySum(3) res5: Int => (Int => Int) = <function1> scala> val curry2 = currySum(2) curry2: Int => (Int => Int) = <function1> scala> curry2(3) res6: Int => Int = <function1> scala> val curry3 = curry2(3) curry3: Int => Int = <function1> scala> curry3(4) res7: Int = 9
ぶんけん
