fieldtest: canonical-type-names — 5 examples, 9 findings

examples/ct_4_qualified_class.ailx

@@ -0,0 +1,26 @@
+; Fieldtest — canonical-type-names, axis 3: QualifiedClassName.
+;
+; A consumer defines a local Box type and writes an instance for
+; `prelude.Eq` instead of bare `Eq`. Per ct.1's load-time validator,
+; class names are NOT module-scoped (they remain workspace-flat,
+; with MethodNameCollision enforcing uniqueness), so a qualified
+; class name in an InstanceDef.class field is a schema violation.
+
+(module ct_4_qualified_class
+
+  (data Box
+    (doc "A trivial Int wrapper.")
+    (ctor MkBox (con Int)))
+
+  (instance
+    (class prelude.Eq)
+    (type (con Box))
+    (method eq
+      (body
+        (lam (params (typed x (con Box)) (typed y (con Box))) (ret (con Bool))
+          (body
+            (match x
+              (case (pat-ctor MkBox a)
+                (match y
+                  (case (pat-ctor MkBox b)
+                    (app == a b)))))))))))