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JDK-6460529 : Provide mixin interfaces for getQualifiedName and getTypeParameters

Details
Type:
Enhancement
Submit Date:
2006-08-16
Status:
Closed
Updated Date:
2011-07-15
Project Name:
JDK
Resolved Date:
2011-07-15
Component:
core-libs
OS:
generic
Sub-Component:
javax.lang.model
CPU:
generic
Priority:
P4
Resolution:
Fixed
Affected Versions:
6
Fixed Versions:

Related Reports
Relates:

Sub Tasks

Description
The JSR 269 language model for elements is very flat, a root Element interface and five direct subinterfaces.  However, certain children interfaces have a method in common and it could be useful to be able to group objects based on the presence of those methods.  For example, TypeElements and PackageElements have a getQualifiedName method and TypeElements and ExecutableElements have a getTypeParameters method.  To allow such grouping,  "QualifiedNamable extends Element" and a "Parameterizable extends Element" interfaces could be added and implemented by the modeling interfaces in question.

                                    

Comments
SUGGESTED FIX

--- old/src/share/classes/com/sun/tools/javac/processing/PrintingProcessor.java	Fri Feb 20 11:56:28 2009
+++ new/src/share/classes/com/sun/tools/javac/processing/PrintingProcessor.java	Fri Feb 20 11:56:27 2009
@@ -125,7 +125,7 @@
                     return this;
 
                 defaultAction(e, true);
-                printFormalTypeParameters(e);
+                printFormalTypeParameters(e, true);
 
                 switch(kind) {
                     case CONSTRUCTOR:
@@ -207,7 +207,7 @@
                 writer.print(" ");
                 writer.print(e.getSimpleName());
 
-                printFormalTypeParameters(e);
+                printFormalTypeParameters(e, false);
 
                 // Print superclass information if informative
                 if (kind == CLASS) {
@@ -364,16 +364,9 @@
             }
         }
 
-        private void printFormalTypeParameters(ExecutableElement executable) {
-            printFormalTypeParameters(executable.getTypeParameters(), true);
-        }
-
-        private void printFormalTypeParameters(TypeElement type) {
-            printFormalTypeParameters(type.getTypeParameters(), false);
-        }
-
-        private void printFormalTypeParameters(List<? extends TypeParameterElement> typeParams,
+        private void printFormalTypeParameters(Parameterizable e,
                                                boolean pad) {
+            List<? extends TypeParameterElement> typeParams = e.getTypeParameters();
             if (typeParams.size() > 0) {
                 writer.print("<");
 
--- old/src/share/classes/javax/lang/model/element/ExecutableElement.java	Fri Feb 20 11:56:30 2009
+++ new/src/share/classes/javax/lang/model/element/ExecutableElement.java	Fri Feb 20 11:56:29 2009
@@ -1,5 +1,5 @@
 /*
- * Copyright 2005-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2005-2009 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -40,7 +40,7 @@
  * @see ExecutableType
  * @since 1.6
  */
-public interface ExecutableElement extends Element {
+public interface ExecutableElement extends Element, Parameterizable {
     /**
      * Returns the formal type parameters of this executable
      * in declaration order.
--- old/src/share/classes/javax/lang/model/element/PackageElement.java	Fri Feb 20 11:56:32 2009
+++ new/src/share/classes/javax/lang/model/element/PackageElement.java	Fri Feb 20 11:56:31 2009
@@ -1,5 +1,5 @@
 /*
- * Copyright 2005-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2005-2009 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,7 +25,6 @@
 
 package javax.lang.model.element;
 
-
 /**
  * Represents a package program element.  Provides access to information
  * about the package and its members.
@@ -36,9 +35,8 @@
  * @see javax.lang.model.util.Elements#getPackageOf
  * @since 1.6
  */
+public interface PackageElement extends Element, QualifiedNameable {
 
-public interface PackageElement extends Element {
-
     /**
      * Returns the fully qualified name of this package.
      * This is also known as the package's <i>canonical</i> name.
--- old/src/share/classes/javax/lang/model/element/TypeElement.java	Fri Feb 20 11:56:33 2009
+++ new/src/share/classes/javax/lang/model/element/TypeElement.java	Fri Feb 20 11:56:33 2009
@@ -1,5 +1,5 @@
 /*
- * Copyright 2005-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2005-2009 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -59,7 +59,7 @@
  * @see DeclaredType
  * @since 1.6
  */
-public interface TypeElement extends Element {
+public interface TypeElement extends Element, Parameterizable, QualifiedNameable {
 
     /**
      * Returns the <i>nesting kind</i> of this type element.
--- /dev/null	Fri Feb 20 11:56:35 2009
+++ new/src/share/classes/javax/lang/model/element/Parameterizable.java	Fri Feb 20 11:56:35 2009
@@ -0,0 +1,45 @@
+/*
+ * Copyright 2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package javax.lang.model.element;
+
+import java.util.List;
+
+/**
+ * A mixin interface for an element that has type parameters.
+ *
+ * @author Joseph D. Darcy
+ * @since 1.7
+ */
+public interface Parameterizable extends Element {
+    /**
+     * Returns the formal type parameters of the type element in
+     * declaration order.
+     *
+     * @return the formal type parameters, or an empty list
+     * if there are none
+     */
+    List<? extends TypeParameterElement> getTypeParameters();
+}
--- /dev/null	Fri Feb 20 11:56:37 2009
+++ new/src/share/classes/javax/lang/model/element/QualifiedNameable.java	Fri Feb 20 11:56:37 2009
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package javax.lang.model.element;
+
+/**
+ * A mixin interface for an element that has a qualified name.
+ *
+ * @author Joseph D. Darcy
+ * @since 1.7
+ */
+public interface QualifiedNameable extends Element {
+    /**
+     * Returns the fully qualified name of an element.
+     *
+     * @return the fully qualified name of an element
+     */
+    Name getQualifiedName();
+}
                                     
2009-02-20
EVALUATION

The utility of providing such mixin interfaces should be evaluated as more experience is gained programming against the API; such a retrofit can be done compatibly in a post-JDK 6 release.
                                     
2006-08-16



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