init commit for annotation processor

Author: FelixAnthonisen

src/main/java/anthonisen/felix/annotationProcessing/MyVariance.java

@@ -0,0 +1,14 @@
+package anthonisen.felix.annotationProcessing;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.SOURCE)
+@Target(ElementType.TYPE_PARAMETER)
+public @interface MyVariance {
+    public VarianceType variance() default VarianceType.INVARIANT;
+
+    public int depth() default Integer.MAX_VALUE;
+}

src/main/java/anthonisen/felix/annotationProcessing/VarianceProcessor.java

@@ -0,0 +1,67 @@
+package anthonisen.felix.annotationProcessing;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+
+import javax.annotation.processing.AbstractProcessor;
+import javax.annotation.processing.Messager;
+import javax.annotation.processing.Processor;
+import javax.annotation.processing.RoundEnvironment;
+import javax.annotation.processing.SupportedAnnotationTypes;
+import javax.annotation.processing.SupportedSourceVersion;
+import javax.lang.model.SourceVersion;
+import javax.lang.model.element.Element;
+import javax.lang.model.element.TypeElement;
+import javax.lang.model.element.TypeParameterElement;
+import javax.tools.Diagnostic.Kind;
+import com.google.auto.service.AutoService;
+
+import anthonisen.felix.astParsing.Covariancer;
+
+@AutoService(Processor.class)
+@SupportedSourceVersion(SourceVersion.RELEASE_17)
+@SupportedAnnotationTypes("anthonisen.felix.annotationProcessing.MyVariance")
+public class VarianceProcessor extends AbstractProcessor {
+
+    Map<String, String> classHierarchy = new HashMap<>();
+
+    @Override
+    public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
+        Messager messager = processingEnv.getMessager();
+        Covariancer covariancer = new Covariancer(messager,
+                System.getProperty("user.dir") + "/src/main/java/anthonisen/felix");
+        messager.printMessage(Kind.NOTE, "Processing annotations:\n");
+        for (Element e : roundEnv.getElementsAnnotatedWith(MyVariance.class)) {
+            MyVariance annotation = e.getAnnotation(MyVariance.class);
+            messager.printMessage(Kind.NOTE, e.getEnclosingElement().getKind().name());
+            if (isClassParameter(e)) {
+                messager.printMessage(Kind.NOTE, "Is part of a class declaration");
+            } else
+                messager.printMessage(Kind.NOTE, "Is part of a method declaration");
+            messager.printMessage(Kind.NOTE, e.getEnclosingElement().getKind().name());
+            switch (annotation.variance()) {
+                case INVARIANT:
+                    messager.printMessage(Kind.NOTE, "Invariant class detected");
+                    break;
+                case CONTRAVARIANT:
+                    messager.printMessage(Kind.NOTE, "Contravariant class detected");
+                    break;
+                case COVARIANT:
+                    messager.printMessage(Kind.NOTE, "Covariant class detected");
+                    break;
+            }
+            TypeParameterElement tE = (TypeParameterElement) e;
+            covariancer.makeCovariant(tE.getEnclosingElement().getSimpleName() + ".java");
+            // Get the enclosing element (this could be a class, method, or constructor)
+
+        }
+        covariancer.applyChanges();
+        return true;
+    }
+
+    // Check whether the type parameter is for a class or a method
+    private static boolean isClassParameter(Element e) {
+        return e.getEnclosingElement().getKind().name().equals("CLASS");
+    }
+}

src/main/java/anthonisen/felix/annotationProcessing/VarianceType.java

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+package anthonisen.felix.annotationProcessing;
+
+public enum VarianceType {
+    INVARIANT,
+    COVARIANT,
+    CONTRAVARIANT
+}