--- /dev/null
+module { export = [main], chr }
+import "StandardLibrary"
+
+data V = V { x :: Double, y :: Double }
+
+main = ()
+ where
+ constraint X V
+ X V { ?x } => print ?x
+ X V { ?y } => print ?y
+ True => X V { x = 1.0, y = 2.0 }
+ True => X V { x = 3.0, y = 4.0 }
+--
+1.0
+2.0
+3.0
+4.0
+()
+--
+module { export = [main], chr }
+import "StandardLibrary"
+
+data V = V { x :: Double, y :: Double }
+
+main = ()
+ where
+ constraint X V
+ True => X V { x = 1.0 }
+--
+9:15-9:28: Field y not defined.
\ No newline at end of file