#7 Add toList(), make foreach() and fornew() correspond to the standard library convention

Author: yruslan

src/main/scala/com/github/yruslan/channel/Channel.scala

@@ -77,12 +77,12 @@ abstract class Channel[T] extends ReadChannel[T] with WriteChannel[T] {
     }
   }
 
-  final override def fornew(f: T => Unit): Unit = {
+  final override def fornew[U](f: T => U): Unit = {
     val valueOpt = tryRecv()
     valueOpt.foreach(v => f(v))
   }
 
-  final override def foreach(f: T => Unit): Unit = {
+  final override def foreach[U](f: T => U): Unit = {
     while (true) {
       lock.lock()
       readers += 1

src/main/scala/com/github/yruslan/channel/ChannelDecoratorFilter.scala

@@ -81,7 +81,7 @@ class ChannelDecoratorFilter[T](inputChannel: ReadChannel[T], pred: T => Boolean
 
   override def recver(action: T => Unit): Selector = inputChannel.recver(t => if (pred(t)) action(t))
 
-  override def fornew(action: T => Unit): Unit = inputChannel.fornew(t => if (pred(t)) action(t))
+  override def fornew[U](action: T => U): Unit = inputChannel.fornew(t => if (pred(t)) action(t))
 
-  override def foreach(action: T => Unit): Unit = inputChannel.foreach(t => if (pred(t)) action(t))
+  override def foreach[U](action: T => U): Unit = inputChannel.foreach(t => if (pred(t)) action(t))
 }

src/main/scala/com/github/yruslan/channel/ChannelDecoratorMap.scala

@@ -38,7 +38,7 @@ class ChannelDecoratorMap[T, U](inputChannel: ReadChannel[T], f: T => U) extends
 
   override def recver(action: U => Unit): Selector = inputChannel.recver(t => action(f(t)))
 
-  override def fornew(action: U => Unit): Unit = inputChannel.fornew(t => action(f(t)))
+  override def fornew[K](action: U => K): Unit = inputChannel.fornew(t => action(f(t)))
 
-  override def foreach(action: U => Unit): Unit = inputChannel.foreach(t => action(f(t)))
+  override def foreach[K](action: U => K): Unit = inputChannel.foreach(t => action(f(t)))
 }

src/main/scala/com/github/yruslan/channel/ReadChannel.scala

@@ -28,6 +28,7 @@ package com.github.yruslan.channel
 
 import com.github.yruslan.channel.impl.Selector
 
+import scala.collection.mutable.ListBuffer
 import scala.concurrent.duration.Duration
 
 trait ReadChannel[T] extends ChannelLike {
@@ -37,9 +38,15 @@ trait ReadChannel[T] extends ChannelLike {
 
   def recver(action: T => Unit): Selector
 
-  def fornew(f: T => Unit): Unit
-  def foreach(f: T => Unit): Unit
+  def fornew[U](f: T => U): Unit
+  def foreach[U](f: T => U): Unit
 
   def map[U](f: T => U): ReadChannel[U] = new ChannelDecoratorMap[T, U](this, f)
   def filter(f: T => Boolean): ReadChannel[T] = new ChannelDecoratorFilter[T](this, f)
+
+  def toList: List[T] = {
+    val lst = new ListBuffer[T]
+    foreach(v => lst += v)
+    lst.toList
+  }
 }

src/main/scala/com/github/yruslan/channel/impl/SimpleLinkedList.scala

@@ -108,7 +108,7 @@ class SimpleLinkedList[T] {
     count = 0
   }
 
-  def foreach(f: T => Unit): Unit = this.synchronized {
+  def foreach[U](f: T => U): Unit = this.synchronized {
     var p = first
     while (p != null) {
       f(p.el)

src/test/scala/com/github/yruslan/channel/ChannelSuite.scala

@@ -866,7 +866,38 @@ class ChannelSuite extends AnyWordSpec with BeforeAndAfterAll {
         }
       }
     }
+  }
+
+  "toList" should {
+    "covert a channel to a list" in {
+      val ch1 = Channel.make[Int](3)
+
+      ch1.send(1)
+      ch1.send(2)
+      ch1.send(3)
+      ch1.close()
+
+      val lst = ch1.toList
+
+      assert(lst == List(1, 2, 3))
+    }
 
+    "convert a mapped filtered channel to a list" in {
+      val ch1 = Channel.make[Int](3)
+
+      val ch2 = ch1
+        .map(v => v * 2)
+        .filter(v => v != 4)
+
+      ch1.send(1)
+      ch1.send(2)
+      ch1.send(3)
+      ch1.close()
+
+      val lst = ch2.toList
+
+      assert(lst == List(2, 6))
+    }
   }
 
   "master/worker model" should {