expand selector demo to account for unions

kubukoz · Nov 11, 2024 · c4bce3a · c4bce3a
1 parent 7629f98
commit c4bce3a
Showing 1 changed file with 54 additions and 4 deletions.
diff --git a/modules/parser-gen/src/main/scala/playground/parsergen/demo.scala b/modules/parser-gen/src/main/scala/playground/parsergen/demo.scala
@@ -1,11 +1,12 @@
-case class Foo(bars: List[Bar]) {
+case class Foo(bars: List[Bar], nodes: List[Node]) {
   def select[A](f: Foo.Selector => Selection[A]): List[A] = f(Foo.Selector(List(this))).path
 }
 
 object Foo {
 
   case class Selector(path: List[Foo]) extends Selection[Foo] {
     def bars: Bar.Selector = Bar.Selector(path.flatMap(_.bars))
+    def nodes: Node.Selector = Node.Selector(path.flatMap(_.nodes))
   }
 
 }
@@ -38,15 +39,64 @@ object Identifier {
   case class Selector(path: List[Identifier]) extends Selection[Identifier]
 }
 
+enum Node {
+  case Ident(i: Identifier)
+  case B(b: Baz)
+
+  def asIdent: Option[Identifier] =
+    this match {
+      case Ident(i) => Some(i)
+      case _        => None
+    }
+
+  def asB: Option[Baz] =
+    this match {
+      case B(b) => Some(b)
+      case _    => None
+    }
+
+}
+
+object Node {
+
+  case class Selector(val path: List[Node]) extends Selection[Node] {
+    def ident: Identifier.Selector = Identifier.Selector(path.flatMap(_.asIdent))
+    def b: Baz.Selector = Baz.Selector(path.flatMap(_.asB))
+  }
+
+}
+
 trait Selection[A] {
   def path: List[A]
 }
 
 @main def demo = {
   import util.chaining.*
 
-  Foo(List(Bar(Some(Baz(List("a", "b").map(Identifier.apply)))))).select(_.bars.baz).pipe(println)
-  Foo(List(Bar(Some(Baz(List("a", "b").map(Identifier.apply))))))
-    .select(_.bars.baz.names)
+  Foo(
+    List(Bar(Some(Baz(List("a", "b").map(Identifier.apply))))),
+    List(Node.Ident(Identifier("aa"))),
+  ).select(_.bars.baz).pipe(println)
+
+  println(
+    Foo(
+      List(Bar(Some(Baz(List("a", "b").map(Identifier.apply))))),
+      List(Node.Ident(Identifier("aa"))),
+    )
+      .select(_.bars.baz.names) ==
+      Foo(
+        List(Bar(Some(Baz(List("a", "b").map(Identifier.apply))))),
+        List(Node.Ident(Identifier("aa"))),
+      )
+        .select(_.bars.baz)
+        .flatMap(_.names)
+  )
+
+  Foo(
+    List(Bar(Some(Baz(List("a", "b").map(Identifier.apply))))),
+    List(Node.Ident(Identifier("aa"))),
+  )
+    .select(_.nodes.ident)
+    // .select(_.nodes.b.names)
     .pipe(println)
 }