Add cases for union and intersection types

Author: aherlihy

compiler/src/dotty/tools/dotc/core/TypeUtils.scala

@@ -137,6 +137,18 @@ class TypeUtils:
           names.zip(values)
         case tp: TypeProxy =>
           tp.superType.namedTupleElementTypesUpTo(bound, normalize)
+        case tp: OrType =>
+          val lhs = tp.tp1.namedTupleElementTypesUpTo(bound, normalize)
+          val rhs = tp.tp2.namedTupleElementTypesUpTo(bound, normalize)
+          if (lhs != rhs) throw TypeError(em"Malformed Union Type: Named Tuple elements must be the same, but $lhs and $rhs were found.")
+          lhs
+        case tp: AndType =>
+          (tp.tp1.namedTupleElementTypesUpTo(bound, normalize), tp.tp2.namedTupleElementTypesUpTo(bound, normalize)) match
+            case (Nil, rhs) => rhs
+            case (lhs, Nil) => lhs
+            case (lhs, rhs) =>
+              if (lhs != rhs) throw TypeError(em"Malformed Intersection Type: Named Tuple elements must be the same, but $lhs and $rhs were found.")
+              lhs
         case t =>
           Nil
 

tests/run/i22150.check

@@ -1 +1,3 @@
 0
+1
+2

tests/run/i22150.scala

@@ -8,5 +8,19 @@ val directionsNT = IArray(
   (dx = -1, dy = 0), // left
 )
 val IArray(UpNT @ _, _, _, _) = directionsNT
+
+object NT:
+//  def foo[T <: (x: Int, y: String)](tup: T): Int =
+//    tup.x
+
+  def union[T](tup: (x: Int, y: String) | (x: Int, y: String)): Int =
+    tup.x
+
+  def intersect[T](tup: (x: Int, y: String) & T): Int =
+    tup.x
+
+
 @main def Test =
   println(UpNT.dx)
+  println(NT.union((1, "a")))
+  println(NT.intersect((2, "b")))