Optional VDOM now via Optional typeclass

Author: japgolly

core/src/main/scala/japgolly/scalajs/react/vdom/Implicits.scala

@@ -6,8 +6,11 @@ import Scalatags._
 
 abstract class LowPri {
   @inline implicit final def _react_fragSeq   [A <% Frag](xs: Seq[A])   : Frag = SeqFrag(xs)
-  @inline implicit final def _react_fragOption[A <% Frag](xs: Option[A]): Frag = SeqFrag(xs.toSeq)
   @inline implicit final def _react_fragArray [A <% Frag](xs: Array[A]) : Frag = SeqFrag[A](xs.toSeq)
+
+//  @inline implicit final def _react_fragOption[A <% Frag](xs: Option[A]): Frag = SeqFrag(xs.toSeq)
+//  @inline implicit final def _react_fragOptional[T[_], A](t: T[A])(implicit o: Optional[T], f: A => Frag): Frag =
+//    o.fold(t, f, ???)
 }
 
 // If you're wondering why abstract class instead of trait, https://issues.scala-lang.org/browse/SI-4767
@@ -29,11 +32,8 @@ abstract class Implicits extends LowPri {
   @inline implicit final def _react_attrRef[R <: Ref]: AttrValue[R] =
     new GenericAttr[R](_.name)
 
-  @inline implicit final def _react_attrOption[A](implicit tc: AttrValue[A]): AttrValue[Option[A]] =
-    new OptionalAttrValue[Option, A](tc, _ foreach _)
-
-  @inline implicit final def _react_attrJsUndef[A](implicit tc: AttrValue[A]): AttrValue[js.UndefOr[A]] =
-    new OptionalAttrValue[js.UndefOr, A](tc, _ foreach _)
+  @inline implicit final def _react_attrOptional[T[_], A](implicit t: Optional[T], a: AttrValue[A]): AttrValue[T[A]] =
+    new OptionalAttrValue[T, A](t, a)
 
   // Styles
   @inline implicit final def _react_styleString : StyleValue[String]  = stringStyleX
@@ -45,20 +45,17 @@ abstract class Implicits extends LowPri {
           implicit final val _react_styleFloat  : StyleValue[Float]   = GenericStyle.stringValue
           implicit final val _react_styleDouble : StyleValue[Double]  = GenericStyle.stringValue
 
-  @inline implicit final def _react_styleOption[A](implicit tc: StyleValue[A]): StyleValue[Option[A]] =
-    new OptionalStyleValue[Option, A](tc, _ foreach _)
-
-  @inline implicit final def _react_styleJsUndef[A](implicit tc: StyleValue[A]): StyleValue[js.UndefOr[A]] =
-    new OptionalStyleValue[js.UndefOr, A](tc, _ foreach _)
+  @inline implicit final def _react_styleOptional[T[_], A](implicit t: Optional[T], a: StyleValue[A]): StyleValue[T[A]] =
+    new OptionalStyleValue[T, A](t, a)
 
   // Frag
   @inline implicit final def _react_fragReactNode[T <% ReactNode](v: T): Frag = new ReactNodeFrag(v)
 
   // TagMod
-  @inline implicit final def _react_nodeSeq    [A <% TagMod](xs: Seq[A])      : TagMod = new SeqNode(xs)
-  @inline implicit final def _react_nodeArray  [A <% TagMod](xs: Array[A])    : TagMod = new SeqNode[A](xs.toSeq)
-  @inline implicit final def _react_nodeOption [A <% TagMod](o: Option[A])    : TagMod = o.fold(EmptyTag)(a => a)
-  @inline implicit final def _react_nodeJsUndef[A <% TagMod](o: js.UndefOr[A]): TagMod = o.fold(EmptyTag)(a => a)
+  @inline implicit final def _react_nodeSeq  [A <% TagMod](xs: Seq[A])      : TagMod = new SeqNode(xs)
+  @inline implicit final def _react_nodeArray[A <% TagMod](xs: Array[A])    : TagMod = new SeqNode[A](xs.toSeq)
+  @inline implicit final def _react_nodeOptional[T[_], A](t: T[A])(implicit o: Optional[T], f: A => TagMod): TagMod =
+    o.fold(t, f, EmptyTag)
 
   // Scalatags misc
   @inline implicit final def _react_styleOrdering                  : Ordering[Style] = Scalatags.styleOrdering

core/src/main/scala/japgolly/scalajs/react/vdom/Optional.scala

@@ -0,0 +1,20 @@
+package japgolly.scalajs.react.vdom
+
+import scala.scalajs.js.UndefOr
+
+trait Optional[T[_]] {
+  def foreach[A](t: T[A])(f: A => Unit): Unit
+  def fold[A, B](t: T[A], f: A => B, b: => B): B
+}
+
+object Optional {
+  implicit object OptionalOption extends Optional[Option] {
+    @inline final override def foreach[A](t: Option[A])(f: (A) => Unit): Unit = t foreach f
+    @inline final override def fold[A, B](t: Option[A], f: A => B, b: => B): B = t.fold(b)(f)
+  }
+
+  implicit object OptionalJsUndefOr extends Optional[UndefOr] {
+    @inline final override def foreach[A](t: UndefOr[A])(f: (A) => Unit): Unit = t foreach f
+    @inline final override def fold[A, B](t: UndefOr[A], f: A => B, b: => B): B = t.fold(b)(f)
+  }
+}

core/src/main/scala/japgolly/scalajs/react/vdom/Scalatags.scala

@@ -181,12 +181,12 @@ private[vdom] object Scalatags {
     override def compare(x: Attr, y: Attr): Int = x.name compareTo y.name
   }
 
-  final class OptionalAttrValue[O[_], T](tc: AttrValue[T], run: (O[T], T => Unit) => Unit) extends AttrValue[O[T]] {
-    override def apply(b: Builder, a: Attr, v: O[T]) = run(v, tc(b, a, _))
+  final class OptionalAttrValue[T[_], A](ot: Optional[T], v: AttrValue[A]) extends AttrValue[T[A]] {
+    override def apply(b: Builder, s: Attr, t: T[A]) = ot.foreach(t)(v(b, s, _))
   }
 
-  final class OptionalStyleValue[O[_], T](tc: StyleValue[T], run: (O[T], T => Unit) => Unit) extends StyleValue[O[T]] {
-    override def apply(b: Builder, a: Style, v: O[T]) = run(v, tc(b, a, _))
+  final class OptionalStyleValue[T[_], A](ot: Optional[T], v: StyleValue[A]) extends StyleValue[T[A]] {
+    override def apply(b: Builder, s: Style, t: T[A]) = ot.foreach(t)(v(b, s, _))
   }
 
   @inline def makeAbstractReactTag(tag: String, void: Boolean, namespaceConfig: Namespace): ReactTag =

scalaz-7.0/src/main/scala/japgolly/scalajs/react/ScalazReact.scala

@@ -9,18 +9,10 @@ import scalaz.effect.IO
 import Scalaz.Id
 import Leibniz.===
 
-package vdom {
-  import Scalatags._
-
-  abstract class ScalazImplicits {
-
-
-  }
-}
-
-object ScalazReact extends vdom.ScalazImplicits {
+object ScalazReact {
   // Don't edit this directly. Run sync-scala70
 
+
   implicit val IoToIo: IO ~> IO = NaturalTransformation.refl[IO]
   implicit object IdToIo extends (Id ~> IO) {
     override def apply[A](a: Id[A]): IO[A] = IO(a)

scalaz-7.1/src/main/scala/japgolly/scalajs/react/ScalazReact.scala

@@ -9,21 +9,12 @@ import scalaz.effect.IO
 import Scalaz.Id
 import Leibniz.===
 
-package vdom {
-  import Scalatags._
+object ScalazReact {
 
-  abstract class ScalazImplicits {
-    @inline implicit final def _react_attrMaybe[A](implicit tc: AttrValue[A]): AttrValue[Maybe[A]] =
-      new OptionalAttrValue[Maybe, A](tc, _.cata(_, ()))
-
-    @inline implicit final def _react_styleMaybe[A](implicit tc: StyleValue[A]): StyleValue[Maybe[A]] =
-      new OptionalStyleValue[Maybe, A](tc, _.cata(_, ()))
-
-    @inline implicit final def _react_nodeMaybe[A <% TagMod](m: Maybe[A]): TagMod = m.cata(a => a, EmptyTag)
+  implicit object OptionalMaybe extends vdom.Optional[Maybe] {
+    @inline final override def foreach[A](m: Maybe[A])(f: (A) => Unit): Unit = m.cata(f, ())
+    @inline final override def fold[A, B](t: Maybe[A], f: A => B, b: => B): B = t.cata(f, b)
   }
-}
-
-object ScalazReact extends vdom.ScalazImplicits {
 
   implicit val IoToIo: IO ~> IO = NaturalTransformation.refl[IO]
   implicit object IdToIo extends (Id ~> IO) {

sync-scala70

@@ -8,7 +8,7 @@ f=src/main/scala/japgolly/scalajs/react/ScalazReact.scala
 echo "$f"
 perl -pe 's!(?<=[^A-Z_]M\[)_!+_!' < $s1/$f > $s0/$f
 sed -i "
-  /Maybe/d;
+  /OptionalMaybe/,/^ *} *$/d;
   /^object/a\  // Don't edit this directly. Run $(basename "$0")
 " $s0/$f
 

test/src/test/scala/japgolly/scalajs/react/CoreTest.scala

@@ -148,7 +148,7 @@ object CoreTest extends TestSuite {
 
         'stringArray - {
           val strArr = Array("hello")
-          test(div(Some("lol"), Some(1), None: Option[String], h1("Hello"), Array(1, 2, 3), strArr, EmptyTag),
+          test(div("lol".some, 1.some, None: Option[String], h1("Hello"), Array(1, 2, 3), strArr, EmptyTag),
             """<div>lol1<h1>Hello</h1>123hello</div>""")
         }
 

test/src/test/scala/japgolly/scalajs/react/PrefixedVdomTest.scala

@@ -148,7 +148,7 @@ object PrefixedVdomTest extends TestSuite {
 
         'stringArray - {
           val strArr = Array("hello")
-          test(<.div(Some("lol"), Some(1), None: Option[String], <.h1("Hello"), Array(1, 2, 3), strArr, EmptyTag),
+          test(<.div("lol".some, 1.some, None: Option[String], <.h1("Hello"), Array(1, 2, 3), strArr, EmptyTag),
             """<div>lol1<h1>Hello</h1>123hello</div>""")
         }