Use custom tags.

Author: cristianoc

jscomp/test/variantsMatching.js

@@ -347,13 +347,12 @@ var MyNullableExtended = {
 
 function area(shape) {
   switch (shape.TAG) {
-    case "Circle" :
-        return Math.PI * Math.pow(shape._0.radius, 2);
-    case "Square" :
-        return Math.pow(shape._0.sideLength, 2);
-    case "Rectangle" :
-        var match = shape._0;
-        return match.width * match.height;
+    case 1 :
+        return Math.PI * Math.pow(shape.radius, 2);
+    case "square" :
+        return Math.pow(shape.sideLength, 2);
+    case "rectangle" :
+        return shape.width * shape.height;
 
   }
 }

jscomp/test/variantsMatching.res

@@ -237,26 +237,10 @@ module TaggedUnions = {
     }
   }
 */
-  type circle = {
-    kind: string,
-    radius: float,
-  }
-
-  type square = {
-    kind: string,
-    sideLength: float,
-  }
-
-  type rectangle = {
-    kind: string,
-    width: float,
-    height: float,
-  }
-
   type shape =
-    | Circle(circle)
-    | Square(square)
-    | Rectangle(rectangle)
+    | @as(1) Circle({kind: string, radius: float})
+    | @as("square") Square({kind: string, sideLength: float})
+    | @as("rectangle") Rectangle({kind: string, width: float, height: float})
 
   let area = (shape: shape): float => {
     switch shape {