feat: order instanceof checks hierarchically

That is, reduce the number of 'instanceof' conditions needing evaluating
in check catalog dispatch logic by having the generator make use of
knowledge about supertype relationships. If it's not an instance of a
more general type, then no need to check for something specific.

com.avaloq.tools.ddk.check.core/src/com/avaloq/tools/ddk/check/jvmmodel/CheckJvmModelInferrer.xtend

@@ -33,6 +33,7 @@ import com.google.inject.Singleton
 import java.util.ArrayList
 import java.util.Collections
 import java.util.List
+import java.util.Map
 import java.util.Objects
 import java.util.TreeMap
 import org.eclipse.core.runtime.preferences.AbstractPreferenceInitializer
@@ -236,7 +237,8 @@ class CheckJvmModelInferrer extends AbstractModelInferrer {
   }
 
   private def void emitInstanceOfConditionals(ITreeAppendable out, List<Context> contexts, CheckCatalog catalog, String baseTypeName) {
-    /* Contexts grouped by fully qualified variable type name.
+    /* Contexts grouped by fully qualified variable type name,
+     * otherwise in order of appearance.
      */
     val contextsByVarType = new TreeMap<String, List<Context>>();
     for (Context context : contexts) {
@@ -245,24 +247,38 @@ class CheckJvmModelInferrer extends AbstractModelInferrer {
       ).add(context);
     }
 
-    for (entry : contextsByVarType.entrySet()) {
-      var String typeName = entry.key;
-      val List<Context> contextsForType = entry.value;
+    /* Ordering for context variable type checks. */
+    val List<JvmTypeReference> contextVarTypes = contexts.map([x | x.contextVariable.type]);
+    val forest = InstanceOfCheckOrderer.orderTypes(contextVarTypes);
 
-      /* Avoid redundant instanceof check and cast for any EObject context. */
+    emitInstanceOfTree(out, forest, null, contextsByVarType, catalog, baseTypeName, 0);
+  }
+
+  private def void emitInstanceOfTree(ITreeAppendable out, InstanceOfCheckOrderer.Forest forest, String node, Map<String, List<Context>> contextsByVarType, CheckCatalog catalog, String baseTypeName, int level) {
+    if (node !== null) {
+      var String typeName = node;
       if (typeName == baseTypeName)
         typeName = null;
-      val varName = if (typeName === null) "object" else "castObject";
+      val varName = if (typeName === null) "object" else "castObject" + (if (level > 1) Integer.toString(level) else "");
 
       out.newLine;
       out.append('''«IF typeName !== null»if (object instanceof «typeName» «varName») «ENDIF»{''');
       out.increaseIndentation;
-      for (context : contextsForType) {
+
+      val contexts = contextsByVarType.get(node);
+      for (context : contexts) {
         emitCheckMethodCall(out, varName, context, catalog); // with preceding newline
       }
+    }
+
+    for (child : forest.getSubTypes(node)) {
+      emitInstanceOfTree(out, forest, child, contextsByVarType, catalog, baseTypeName, level + 1);
+    }
+
+    if (node !== null) {
       out.decreaseIndentation;
       out.newLine;
-      out.append('''}''');
+      out.append('}');
     }
   }