Mercurial > jdk8-mips64-public > langtools / file revision

 /*

  * Copyright (c) 2005, 2013, Oracle and/or its affiliates. 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.  Oracle designates this

  * particular file as subject to the "Classpath" exception as provided

  * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  */

 package javax.lang.model;

 import java.util.Collections;

 import java.util.Set;

 import java.util.HashSet;

 /**

  * Source versions of the Java™ programming language.

  *

  * See the appropriate edition of

  * <cite>The Java&trade; Language Specification</cite>

  * for information about a particular source version.

  *

  * <p>Note that additional source version constants will be added to

  * model future releases of the language.

  *

  * @author Joseph D. Darcy

  * @author Scott Seligman

  * @author Peter von der Ahé

  * @since 1.6

  */

 public enum SourceVersion {

     /*

      * Summary of language evolution

      * 1.1: nested classes

      * 1.2: strictfp

      * 1.3: no changes

      * 1.4: assert

      * 1.5: annotations, generics, autoboxing, var-args...

      * 1.6: no changes

      */

     /**

      * The original version.

      *

      * The language described in

      * <cite>The Java&trade; Language Specification, First Edition</cite>.

      */

     RELEASE_0,

     /**

      * The version recognized by the Java Platform 1.1.

      *

      * The language is {@code RELEASE_0} augmented with nested classes as described in the 1.1 update to

      * <cite>The Java&trade; Language Specification, First Edition</cite>.

      */

     RELEASE_1,

     /**

      * The version recognized by the Java 2 Platform, Standard Edition,

      * v 1.2.

      *

      * The language described in

      * <cite>The Java&trade; Language Specification,

      * Second Edition</cite>, which includes the {@code

      * strictfp} modifier.

      */

     RELEASE_2,

     /**

      * The version recognized by the Java 2 Platform, Standard Edition,

      * v 1.3.

      *

      * No major changes from {@code RELEASE_2}.

      */

     RELEASE_3,

     /**

      * The version recognized by the Java 2 Platform, Standard Edition,

      * v 1.4.

      *

      * Added a simple assertion facility.

      */

     RELEASE_4,

     /**

      * The version recognized by the Java 2 Platform, Standard

      * Edition 5.0.

      *

      * The language described in

      * <cite>The Java&trade; Language Specification,

      * Third Edition</cite>.  First release to support

      * generics, annotations, autoboxing, var-args, enhanced {@code

      * for} loop, and hexadecimal floating-point literals.

      */

     RELEASE_5,

     /**

      * The version recognized by the Java Platform, Standard Edition

      * 6.

      *

      * No major changes from {@code RELEASE_5}.

      */

     RELEASE_6,

     /**

      * The version recognized by the Java Platform, Standard Edition

      * 7.

      *

      * @since 1.7

      */

     RELEASE_7,

     /**

      * The version recognized by the Java Platform, Standard Edition

      * 8.

      *

      * @since 1.8

      */

     RELEASE_8;

     // Note that when adding constants for newer releases, the

     // behavior of latest() and latestSupported() must be updated too.

     /**

      * Returns the latest source version that can be modeled.

      *

      * @return the latest source version that can be modeled

      */

     public static SourceVersion latest() {

         return RELEASE_8;

     }

     private static final SourceVersion latestSupported = getLatestSupported();

     private static SourceVersion getLatestSupported() {

         try {

             String specVersion = System.getProperty("java.specification.version");

             if ("1.8".equals(specVersion))

                 return RELEASE_8;

             else if("1.7".equals(specVersion))

                 return RELEASE_7;

             else if("1.6".equals(specVersion))

                 return RELEASE_6;

         } catch (SecurityException se) {}

         return RELEASE_5;

     }

     /**

      * Returns the latest source version fully supported by the

      * current execution environment.  {@code RELEASE_5} or later must

      * be returned.

      *

      * @return the latest source version that is fully supported

      */

     public static SourceVersion latestSupported() {

         return latestSupported;

     }

     /**

      * Returns whether or not {@code name} is a syntactically valid

      * identifier (simple name) or keyword in the latest source

      * version.  The method returns {@code true} if the name consists

      * of an initial character for which {@link

      * Character#isJavaIdentifierStart(int)} returns {@code true},

      * followed only by characters for which {@link

      * Character#isJavaIdentifierPart(int)} returns {@code true}.

      * This pattern matches regular identifiers, keywords, and the

      * literals {@code "true"}, {@code "false"}, and {@code "null"}.

      * The method returns {@code false} for all other strings.

      *

      * @param name the string to check

      * @return {@code true} if this string is a

      * syntactically valid identifier or keyword, {@code false}

      * otherwise.

      */

     public static boolean isIdentifier(CharSequence name) {

         String id = name.toString();

         if (id.length() == 0) {

             return false;

         }

         int cp = id.codePointAt(0);

         if (!Character.isJavaIdentifierStart(cp)) {

             return false;

         }

         for (int i = Character.charCount(cp);

                 i < id.length();

                 i += Character.charCount(cp)) {

             cp = id.codePointAt(i);

             if (!Character.isJavaIdentifierPart(cp)) {

                 return false;

             }

         }

         return true;

     }

     /**

      *  Returns whether or not {@code name} is a syntactically valid

      *  qualified name in the latest source version.  Unlike {@link

      *  #isIdentifier isIdentifier}, this method returns {@code false}

      *  for keywords and literals.

      *

      * @param name the string to check

      * @return {@code true} if this string is a

      * syntactically valid name, {@code false} otherwise.

      * @jls 6.2 Names and Identifiers

      */

     public static boolean isName(CharSequence name) {

         String id = name.toString();

         for(String s : id.split("\\.", -1)) {

             if (!isIdentifier(s) || isKeyword(s))

                 return false;

         }

         return true;

     }

     private final static Set<String> keywords;

     static {

         Set<String> s = new HashSet<String>();

         String [] kws = {

             "abstract", "continue",     "for",          "new",          "switch",

             "assert",   "default",      "if",           "package",      "synchronized",

             "boolean",  "do",           "goto",         "private",      "this",

             "break",    "double",       "implements",   "protected",    "throw",

             "byte",     "else",         "import",       "public",       "throws",

             "case",     "enum",         "instanceof",   "return",       "transient",

             "catch",    "extends",      "int",          "short",        "try",

             "char",     "final",        "interface",    "static",       "void",

             "class",    "finally",      "long",         "strictfp",     "volatile",

             "const",    "float",        "native",       "super",        "while",

             // literals

             "null",     "true",         "false"

         };

         for(String kw : kws)

             s.add(kw);

         keywords = Collections.unmodifiableSet(s);

     }

     /**

      *  Returns whether or not {@code s} is a keyword or literal in the

      *  latest source version.

      *

      * @param s the string to check

      * @return {@code true} if {@code s} is a keyword or literal, {@code false} otherwise.

      */

     public static boolean isKeyword(CharSequence s) {

         String keywordOrLiteral = s.toString();

         return keywords.contains(keywordOrLiteral);

     }

 }