Added map and collect support in Observable, Channel, Var, and Val.

Updated to Scala 2.12.3 and SBT 0.13.16.

Author: darkfrog26

README.md

@@ -276,6 +276,12 @@ We need implicits to be able to convert between the two, but now changes to one
 
 ## Versions
 
+### Features for 2.1.0 (In-Progress)
+
+* [ ] Features for mapping from one Observable to another
+    * [X] map
+    * [X] collect
+
 ### Features for 2.0.0 (Released 2017.06.15)
 
 * [X] Complete re-write of internal and recursive state system for better modularity and stability

build.sbt

@@ -1,8 +1,8 @@
 name := "reactify"
 organization in ThisBuild := "com.outr"
-version in ThisBuild := "2.0.6"
-scalaVersion in ThisBuild := "2.12.2"
-crossScalaVersions in ThisBuild := List("2.12.2", "2.11.11", "2.13.0-M1")
+version in ThisBuild := "2.1.0-SNAPSHOT"
+scalaVersion in ThisBuild := "2.12.3"
+crossScalaVersions in ThisBuild := List("2.12.3", "2.11.11", "2.13.0-M1")
 
 lazy val root = project.in(file("."))
   .aggregate(js, jvm)

project/build.properties

@@ -1 +1 @@
-sbt.version=0.13.15
+sbt.version=0.13.16

shared/src/main/scala/reactify/Channel.scala

@@ -14,6 +14,10 @@ trait Channel[T] extends Observable[T] {
     * @param value the value to apply
     */
   def set(value: => T): Unit
+
+  override def map[R](f: (T) => R): Channel[R] = super.map(f).asInstanceOf[Channel[R]]
+
+  override def collect[R](f: PartialFunction[T, R]): Channel[R] = super.collect(f).asInstanceOf[Channel[R]]
 }
 
 object Channel {

shared/src/main/scala/reactify/Observable.scala

@@ -89,6 +89,28 @@ trait Observable[T] {
     */
   def changes(listener: ChangeListener[T]): Listener[T] = attach(ChangeListener.createFunction(listener, None))
 
+  /**
+    * Maps the Observable to another type.
+    *
+    * @param f function to handle the mapping from T to R
+    * @tparam R the type of the new Observable
+    * @return Observable[R]
+    */
+  def map[R](f: T => R): Observable[R] = {
+    val channel = Channel[R]
+    attach(t => channel := f(t))
+    channel
+  }
+
+  def collect[R](f: PartialFunction[T, R]): Observable[R] = {
+    val channel = Channel[R]
+    val lifted = f.lift
+    attach { t =>
+      lifted(t).foreach(v => channel.set(v))
+    }
+    channel
+  }
+
   protected[reactify] def fire(value: T, `type`: InvocationType): Unit = Invocation().wrap {
     fireRecursive(value, `type`, Invocation(), observers)
   }

shared/src/main/scala/reactify/Val.scala

@@ -18,6 +18,8 @@ class Val[T](function: () => T,
              onUpdate: Boolean = false) extends AbstractState[T](distinct, cache, recursion, transactional, onUpdate) {
   set(function())
 
+  override def map[R](f: (T) => R): Val[R] = Val(f(this()))
+
   override def toString: String = s"Val($get)"
 }
 

shared/src/main/scala/reactify/Var.scala

@@ -19,6 +19,8 @@ class Var[T](function: () => T,
   override def set(value: => T): Unit = super.set(value)
   def asVal: Val[T] = this
 
+  override def map[R](f: (T) => R): Var[R] = Var(f(this()))
+
   override def toString: String = s"Var($get)"
 }
 

shared/src/test/scala/specs/BasicSpec.scala

@@ -28,6 +28,32 @@ class BasicSpec extends WordSpec with Matchers {
       changes should be(2)
       lastChange should be(Some("Test 2"))
     }
+    "map a Channel to another typed Channel" in {
+      val c1 = Channel[String]
+      val c2 = c1.map(_.reverse)
+
+      var lastValue: Option[String] = None
+      c2.attach(v => lastValue = Some(v))
+
+      c1 := "Testing"
+      lastValue should be(Some("gnitseT"))
+    }
+    "collect a Channel to another typed Channel" in {
+      val IntRegex = """(\d+)""".r
+      val c1 = Channel[String]
+      val c2 = c1.collect {
+        case IntRegex(v) => v.toInt
+      }
+
+      var lastValue: Option[Int] = None
+      c2.attach(v => lastValue = Some(v))
+
+      c1 := "Testing"
+      lastValue should be(None)
+
+      c1 := "50"
+      lastValue should be(Some(50))
+    }
   }
   "Vals" should {
     "contain the proper value" in {
@@ -253,7 +279,7 @@ class BasicSpec extends WordSpec with Matchers {
       }
       users := List(adam, betty, chris, debby)
 
-      val fiveLetterNames = Val(users.collect {
+      val fiveLetterNames = Val(users().collect {
         case user if user.name.length == 5 => user.name()
       })
       fiveLetterNames() should be(List("Betty", "Chris", "Debby"))
@@ -383,7 +409,7 @@ class BasicSpec extends WordSpec with Matchers {
       }
       val complex: Var[Option[Complex]] = Var[Option[Complex]](None)
       var active = false
-      val enabled: Val[Boolean] = Val(complex.flatMap(_.screen.map(_.active())).getOrElse(false))
+      val enabled: Val[Boolean] = Val(complex.flatMap(_.screen().map(_.active())).getOrElse(false))
       enabled.attach(active = _)
       active should be(false)
       enabled() should be(false)