only create reference creation and resolution methods for types that can be instantiated

src/main/jastadd/Analysis.jrag

@@ -160,12 +160,40 @@ aspect ComponentAnalysis {
     return set;
   }
 
-  //--- needUnresolvedClass ---
-  syn boolean TypeDecl.needUnresolvedClass() {
-    // a TypeDecl needs an unresolved class, if it can appear in a relation
-    // TODO
+  /**
+   * @return a set of all types that refer to this type using a non-containment relation
+   */
+  coll Set<TypeDecl> TypeDecl.referencingTypes() [new HashSet<TypeDecl>()];
+  RelationComponent contributes opposite().getTypeUse().decl()
+    when opposite().isNavigable()
+    to TypeDecl.referencingTypes()
+    for getTypeUse().decl();
+
+  /**
+   * @return true, if the type can be the target of a non-containment relation
+   */
+  syn boolean TypeDecl.isReferenceTarget() {
+    return !referencingTypes().isEmpty();
+  }
+
+  /**
+   * @return true, if the type or one of its abstract supertypes can be the target of a non-containment relation
+   */
+  syn boolean TypeDecl.requiresUresolvedClass() {
+    if (referencingTypes().isEmpty()) {
+      // if the type is not referenced itself, it may still be required by an abstract supertype that is referenced
+      TypeDecl decl = this;
+      while (decl.hasSuper()) {
+        decl = decl.getSuper().decl();
+        if (decl.getAbstract() && !decl.referencingTypes().isEmpty()) {
+          return true;
+        }
+      }
+      return false;
+    } else {
       return true;
     }
+  }
 
   //--- isList ---
   syn boolean Component.isList() = false;
@@ -201,6 +229,8 @@ aspect InstanceSupplier {
     return subDecls;
   }
 
+  syn boolean TypeDecl.instantiable() = instantiableSubType() != null;
+
   //--- instantiableSubType ---
   syn TypeDecl TypeDecl.instantiableSubType() {
     if (getAbstract() == false) {

src/main/jastadd/backend/NameResolution.jadd

@@ -149,8 +149,10 @@ aspect NameResolutionHelper {
     sb.append("aspect ReferenceCreation {\n\n");
 
     for (TypeDecl decl : getTypeDeclList()) {
+      if (decl.isReferenceTarget()) {
         decl.createReferenceCreator(sb);
       }
+    }
 
     sb.append("}\n\n");
 
@@ -172,7 +174,7 @@ aspect NameResolutionHelper {
     sb.append(ind(1) + "}\n\n");
 
     for (TypeDecl td: getTypeDecls()) {
-      if (td.needUnresolvedClass()) {
+      if (td.requiresUresolvedClass()) {
         td.generateUnresolvedClass(sb);
       }
     }
@@ -182,11 +184,10 @@ aspect NameResolutionHelper {
 
   public void TypeDecl.createReferenceCreator(StringBuilder sb) {
 
+    if (!instantiable()) {
+      System.out.println("WARNING: unable to find instantiable subtype for " + getID() + "! Skipping the creation of reference creator methods.");
+    } else {
       TypeDecl instantiableSubType = instantiableSubType();
-    if (instantiableSubType == null) {
-      throw new RuntimeException("unable to find instantiable subtype for " + getID());
-    }
-
       sb.append(ind(1) + "public static " + getID() + " " + getID() + "." + createRefMethod + "(String ref) {\n");
         sb.append(ind(2) + unresolvedPrefix + instantiableSubType.getID() + " unresolvedNode = new " + unresolvedPrefix + instantiableSubType.getID() + "();\n");
         sb.append(ind(2) + "unresolvedNode.set" + unresolvedPrefix + "Token(ref);\n");
@@ -201,6 +202,7 @@ aspect NameResolutionHelper {
         sb.append(ind(2) + "return unresolvedNode;\n");
       sb.append(ind(1) + "}\n");
     }
+  }
 
   public void TypeDecl.generateContextIndependentNameResolution(StringBuilder sb) {
     sb.append(ind(1) + "// context-independent name resolution\n");

src/main/jastadd/backend/Serializer.jadd

@@ -268,6 +268,9 @@ aspect Serializer {
   public void TypeDecl.deserialize(StringBuilder sb) {
 
     sb.append(ind(1) + "public static " + getID() + " " + getID() + ".deserialize(java.io.File file) throws DeserializationException {\n");
+
+    if (instantiable()) {
+
       sb.append(ind(2) + "try {\n");
       sb.append(ind(3) + "com.fasterxml.jackson.databind.ObjectMapper mapper = new com.fasterxml.jackson.databind.ObjectMapper();\n");
       sb.append(ind(3) + "com.fasterxml.jackson.core.JsonFactory factory = mapper.getFactory();\n");
@@ -329,6 +332,9 @@ aspect Serializer {
       }
 
       sb.append(ind(2) + "return element;\n");
+    } else {
+      sb.append(ind(2) + "throw new DeserializationException(\"Unable to deserialize type \\\"" + getID() + "\\\" because it is not instantiable.\");\n");
+    }
     sb.append(ind(1) + "}\n");
 
   }

src/test/jastadd/relations/Relations.relast

@@ -62,3 +62,5 @@ G : C ::= [D] ;
 
 // line comment with special symbols like |, *, ->, <-, <->, [A], B ::= C, :, \n, \r, ~, #, /A/
 /* block comment with special symbols like |, *, ->, <-, <->, [A], B ::= C, :, \n, \r, ~, #, /A/ */
+
+abstract Uninstantiable:A;

src/test/jastadd/resolver/Resolver.relast

@@ -21,3 +21,5 @@ rel A.Bi6? <-> B.Bi6*;
 rel A.Bi7* <-> B.Bi7;
 rel A.Bi8* <-> B.Bi8?;
 rel A.Bi9* <-> B.Bi9*;
+
+abstract Uninstantiable:A;

src/test/jastadd/resolver2/Resolver.relast

@@ -21,3 +21,5 @@ rel A.Bi6l? <-> B.Bi6*;
 rel A.Bi7l* <-> B.Bi7;
 rel A.Bi8l* <-> B.Bi8?;
 rel A.Bi9l* <-> B.Bi9*;
+
+abstract Uninstantiable:A;

src/test/jastadd/serializer-manual-relative/Serializer.relast

@@ -21,3 +21,5 @@ rel A.Bi6? <-> B.Bi6*;
 rel A.Bi9* <-> B.Bi9*;
 
 rel Root.D <-> D.Root?;
+
+abstract Uninstantiable:A;

src/test/jastadd/serializer-manual/Serializer.relast

@@ -21,3 +21,5 @@ rel A.Bi6? <-> B.Bi6*;
 rel A.Bi9* <-> B.Bi9*;
 
 rel Root.D <-> D.Root?;
+
+abstract Uninstantiable:A;

src/test/jastadd/serializer-names/Serializer.relast

@@ -32,3 +32,5 @@ rel A.Bi5? <-> B.Bi5?;
 rel A.Bi6? <-> B.Bi6*;
 
 rel A.Bi9* <-> B.Bi9*;
+
+abstract Uninstantiable:A;

src/test/jastadd/serializer-pointer/Serializer.relast

@@ -21,3 +21,5 @@ rel A.Bi6? <-> B.Bi6*;
 rel A.Bi9* <-> B.Bi9*;
 
 rel Root.D <-> D.Root?;
+
+abstract Uninstantiable:A;

src/test/jastadd/serializer/Serializer.relast

@@ -32,3 +32,5 @@ rel A.Bi5? <-> B.Bi5?;
 rel A.Bi6? <-> B.Bi6*;
 
 rel A.Bi9* <-> B.Bi9*;
+
+abstract Uninstantiable:A;