add Var.prism/subType methods without seed and rename *Optic methods

cornerman · Nov 17, 2023 · c5dfa9c · c5dfa9c
1 parent fe2912e
commit c5dfa9c
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Showing 2 changed files with 48 additions and 10 deletions.
diff --git a/reactive/src/main/scala/colibri/reactive/Reactive.scala b/reactive/src/main/scala/colibri/reactive/Reactive.scala
@@ -295,18 +295,34 @@ trait Var[A] extends VarState[A] with Rx[A] {
   final def lens[B](read: A => B)(write: (A, B) => A)(implicit owner: NowOwner): Var[B] =
     transformVar(_.contramap(write(now(), _)))(_.map(read))
 
-  final def prism[A2](f: A2 => A)(g: A => Option[A2])(seed: => A2): Var[A2] =
+  final def prismSeed[A2](f: A2 => A)(g: A => Option[A2])(seed: => A2): Var[A2] =
     transformVar(_.contramap(f))(rx => Rx.observableSync(rx.observable.mapFilter(g).prependEval(seed)))
 
-  final def subType[A2 <: A: ClassTag](seed: => A2): Var[A2] = prism[A2]((x: A2) => x) {
+  final def prism[A2](f: A2 => A)(g: A => Option[A2]): Rx[Option[Var[A2]]] =
+    this.scan(Option.empty[Var[A2]]) { (prevVar, value) =>
+      (prevVar, g(value)) match {
+        case (variable@Some(_), Some(_)) => variable
+        case (None, Some(result)) => Some(prismSeed(f)(g)(result))
+        case (_, None) => None
+      }
+    }
+
+  final def subTypeSeed[A2 <: A: ClassTag](seed: => A2): Var[A2] = prismSeed[A2]((x: A2) => x) {
     case a: A2 => Some(a)
     case _     => None
   }(seed)
 
-  final def imapO[B](optic: Iso[A, B]): Var[B]                = imap(optic.reverseGet(_))(optic.get(_))
-  final def lensO[B](optic: Lens[A, B]): Var[B]               = lens(optic.get(_))((base, zoomed) => optic.replace(zoomed)(base))
-  final def prismO[B](optic: Prism[A, B])(seed: => B): Var[B] =
-    prism(optic.reverseGet(_))(optic.getOption(_))(seed)
+  final def subType[A2 <: A: ClassTag]: Rx[Option[Var[A2]]] = prism[A2]((x: A2) => x) {
+    case a: A2 => Some(a)
+    case _     => None
+  }
+
+  final def imapOptic[B](optic: Iso[A, B]): Var[B]                = imap(optic.reverseGet(_))(optic.get(_))
+  final def lensOptic[B](optic: Lens[A, B]): Var[B]               = lens(optic.get(_))((base, zoomed) => optic.replace(zoomed)(base))
+  final def prismSeedOptic[B](optic: Prism[A, B])(seed: => B): Var[B] =
+    prismSeed(optic.reverseGet(_))(optic.getOption(_))(seed)
+  final def prismOptic[B](optic: Prism[A, B]): Rx[Option[Var[B]]]         =
+    prism(optic.reverseGet(_))(optic.getOption(_))
 }
 
 object Var {

diff --git a/reactive/src/test/scala/colibri/ReactiveSpec.scala b/reactive/src/test/scala/colibri/ReactiveSpec.scala
@@ -858,7 +858,7 @@ class ReactiveSpec extends AsyncFlatSpec with Matchers {
     case class Employee(name: String, company: Company)
 
     val employee = Var(Employee("jules", Company("wules", 7)))
-    val zipcode  = employee.lensO(GenLens[Employee](_.company.zipcode))
+    val zipcode  = employee.lensOptic(GenLens[Employee](_.company.zipcode))
 
     zipcode.unsafeSubscribe()
 
@@ -882,42 +882,64 @@ class ReactiveSpec extends AsyncFlatSpec with Matchers {
     val eventVar: Var[Event]    = Var[Event](EventA(0))
     val eventNotVar: Var[Event] = Var[Event](EventB(""))
 
-    val eventAVar    = eventVar.prismO(GenPrism[Event, EventA])(null)
-    val eventAVar2   = eventVar.subType[EventA](null)
-    val eventNotAVar = eventNotVar.prismO(GenPrism[Event, EventA])(null)
+    val eventAVar    = eventVar.prismSeedOptic(GenPrism[Event, EventA])(null)
+    val eventAVar2   = eventVar.subTypeSeed[EventA](null)
+    val eventNotAVar = eventNotVar.prismSeedOptic(GenPrism[Event, EventA])(null)
+    val eventAVarRx  = eventVar.prismOptic(GenPrism[Event, EventA])
+    val eventAVarRx2  = eventVar.subType[EventA]
 
     eventAVar.unsafeSubscribe()
     eventAVar2.unsafeSubscribe()
     eventNotAVar.unsafeSubscribe()
+    eventAVarRx.unsafeSubscribe()
+    eventAVarRx2.unsafeSubscribe()
 
     eventVar.nowIfSubscribed() shouldBe EventA(0)
     eventAVar.nowIfSubscribed() shouldBe EventA(0)
     eventAVar2.nowIfSubscribed() shouldBe EventA(0)
     eventNotAVar.nowIfSubscribed() shouldBe null
+    eventAVarRx.nowIfSubscribed().get.now() shouldBe EventA(0)
+    eventAVarRx2.nowIfSubscribed().get.now() shouldBe EventA(0)
 
+    val prevEventAVarRx = eventAVarRx.nowIfSubscribed().get
+    val prevEventAVarRx2 = eventAVarRx2.nowIfSubscribed().get
     eventAVar.set(EventA(1))
 
     eventVar.nowIfSubscribed() shouldBe EventA(1)
     eventAVar.nowIfSubscribed() shouldBe EventA(1)
     eventAVar2.nowIfSubscribed() shouldBe EventA(1)
+    eventNotAVar.nowIfSubscribed() shouldBe null
+    eventAVarRx.nowIfSubscribed().get.now() shouldBe EventA(1)
+    eventAVarRx.nowIfSubscribed().get shouldBe prevEventAVarRx
+    eventAVarRx2.nowIfSubscribed().get.now() shouldBe EventA(1)
+    eventAVarRx2.nowIfSubscribed().get shouldBe prevEventAVarRx2
 
     eventVar.set(EventB("he"))
 
     eventVar.nowIfSubscribed() shouldBe EventB("he")
     eventAVar.nowIfSubscribed() shouldBe EventA(1)
     eventAVar2.nowIfSubscribed() shouldBe EventA(1)
+    eventNotAVar.nowIfSubscribed() shouldBe null
+    eventAVarRx.nowIfSubscribed() shouldBe None
+    eventAVarRx2.nowIfSubscribed() shouldBe None
 
     eventAVar.set(EventA(2))
 
     eventVar.nowIfSubscribed() shouldBe EventA(2)
     eventAVar.nowIfSubscribed() shouldBe EventA(2)
     eventAVar2.nowIfSubscribed() shouldBe EventA(2)
+    eventNotAVar.nowIfSubscribed() shouldBe null
+    eventAVarRx.nowIfSubscribed().get.now() shouldBe EventA(2)
+    eventAVarRx2.nowIfSubscribed().get.now() shouldBe EventA(2)
 
     eventVar.set(EventA(3))
 
     eventVar.nowIfSubscribed() shouldBe EventA(3)
     eventAVar.nowIfSubscribed() shouldBe EventA(3)
     eventAVar2.nowIfSubscribed() shouldBe EventA(3)
+    eventNotAVar.nowIfSubscribed() shouldBe null
+    eventAVarRx.nowIfSubscribed().get.now() shouldBe EventA(3)
+    eventAVarRx2.nowIfSubscribed().get.now() shouldBe EventA(3)
   }
 
   it should "map and now()" in {