Merge pull request twitter#274 from twitter/jco/261

Remove extends function from algebird

algebird-core/src/main/scala/com/twitter/algebird/Aggregator.scala

@@ -37,7 +37,7 @@ object Aggregator extends java.io.Serializable {
   }
 }
 
-trait Aggregator[-A,B,+C] extends Function1[TraversableOnce[A], C] with java.io.Serializable { self =>
+trait Aggregator[-A,B,+C] extends java.io.Serializable { self =>
   def prepare(input : A) : B
   def reduce(l : B, r : B) : B
   def present(reduction : B) : C

algebird-core/src/main/scala/com/twitter/algebird/CountMinSketch.scala

@@ -362,7 +362,7 @@ object CMSInstance {
  *
  *   h(x) = [a * x + b (mod p)] (mod m)
  */
-case class CMSHash(a : Int, b : Int, width : Int) extends Function1[Long, Int] {
+case class CMSHash(a : Int, b : Int, width : Int) {
 
   val PRIME_MODULUS = (1L << 31) - 1
 

algebird-core/src/main/scala/com/twitter/algebird/Interval.scala

@@ -22,7 +22,7 @@ package com.twitter.algebird
  * TODO remove T => Boolean. it ruins toString and doesn't help anything
  * https://github.com/twitter/algebird/issues/261
  */
-sealed trait Interval[T] extends (T => Boolean) with java.io.Serializable {
+sealed trait Interval[T] extends java.io.Serializable {
   def contains(t: T): Boolean
 
   def intersect(that: Interval[T]): Interval[T]

algebird-core/src/main/scala/com/twitter/algebird/Metric.scala

@@ -101,6 +101,6 @@ object Metric {
 }
 
 @implicitNotFound(msg = "Cannot find Metric type class for ${V}")
-trait Metric[@specialized(Int,Long,Float,Double) -V] extends Function2[V, V, Double] with java.io.Serializable {
+trait Metric[@specialized(Int,Long,Float,Double) -V] extends java.io.Serializable {
   def apply(v1: V, v2: V): Double
 }

algebird-core/src/main/scala/com/twitter/algebird/SketchMap.scala

@@ -28,8 +28,7 @@ import scala.collection.breakOut
  * Hashes an arbitrary key type to one that the Sketch Map can use.
  */
 case class SketchMapHash[K](hasher: CMSHash, seed: Int)
-                            (implicit serialization: K => Array[Byte])
-                            extends Function1[K, Int] {
+                            (implicit serialization: K => Array[Byte]) {
   def apply(obj: K): Int = {
     val (first, second) = MurmurHash128(seed)(serialization(obj))
     hasher(first ^ second)
@@ -121,7 +120,8 @@ case class SketchMapParams[K](seed: Int, eps: Double, delta: Double, heavyHitter
     val numHashes = depth
     val numCounters = width
     (0 to (numHashes - 1)).map { _ =>
-      SketchMapHash(CMSHash(r.nextInt, 0, numCounters), seed)(serialization)
+      val smhash: SketchMapHash[K] = SketchMapHash(CMSHash(r.nextInt, 0, numCounters), seed)(serialization)
+      new (K => Int) { override def apply(k: K) = smhash(k) }
     }
   }
 

algebird-core/src/main/scala/com/twitter/algebird/SummingQueue.scala

@@ -42,7 +42,7 @@ object SummingQueue {
 }
 
 class SummingQueue[V] private (capacity: Int)(override implicit val semigroup: Semigroup[V])
-  extends (V => Option[V]) with StatefulSummer[V] {
+  extends StatefulSummer[V] {
 
   private val queueOption: Option[ArrayBlockingQueue[V]] =
     if (capacity > 0) Some(new ArrayBlockingQueue[V](capacity, true)) else None

algebird-test/src/test/scala/com/twitter/algebird/BloomFilterTest.scala

@@ -26,10 +26,10 @@ object BloomFilterLaws extends Properties("BloomFilter") {
 
 object BFHashIndices extends Properties("BFHash") {
   import org.scalacheck.Prop.forAll
-  
+
   val NUM_HASHES = 10
   val WIDTH = 4752800
-  
+
   val SEED = 1
 
   implicit val bfHash: Arbitrary[BFHash] =
@@ -39,13 +39,13 @@ object BFHashIndices extends Properties("BFHash") {
         width <- choose(100, 5000000)
       } yield BFHash(hashes, width, SEED)
     }
-   
-  property("Indices are non negative") = forAll{ (hash: BFHash, v: Long) => hash.apply(v.toString).forall(_ >= 0) } 
-   
+
+  property("Indices are non negative") = forAll{ (hash: BFHash, v: Long) => hash.apply(v.toString).forall(_ >= 0) }
+
   /**
-   *   This is the version of the BFHash as of before the "negative values fix" 
+   *   This is the version of the BFHash as of before the "negative values fix"
    */
-  case class NegativeBFHash(numHashes: Int, width: Int, seed: Long = 0L) extends Function1[String, Iterable[Int]]{
+  case class NegativeBFHash(numHashes: Int, width: Int, seed: Long = 0L) {
     val size = numHashes
 
     def apply(s: String) = nextHash(s.getBytes, numHashes)
@@ -72,7 +72,7 @@ object BFHashIndices extends Properties("BFHash") {
       }
     }
   }
-  
+
   implicit val pairOfHashes: Arbitrary[(BFHash, NegativeBFHash)] =
     Arbitrary {
       for {
@@ -81,7 +81,7 @@ object BFHashIndices extends Properties("BFHash") {
       } yield (BFHash(hashes, width, SEED), NegativeBFHash(hashes, width, SEED))
     }
 
-  property("Indices of the two versions of BFHashes are the same, unless the first one contains negative index") = 
+  property("Indices of the two versions of BFHashes are the same, unless the first one contains negative index") =
     forAll{
       (pair: (BFHash, NegativeBFHash), v: Long) =>
         val s = v.toString
@@ -187,7 +187,7 @@ class BloomFilterTest extends Specification {
     }
 
     /**
-     * this test failed before the fix for https://github.com/twitter/algebird/issues/229 
+     * this test failed before the fix for https://github.com/twitter/algebird/issues/229
      */
     "not have negative hash values" in {
       val NUM_HASHES = 2