aoqi@0: /*
aoqi@0:  * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.  Oracle designates this
aoqi@0:  * particular file as subject to the "Classpath" exception as provided
aoqi@0:  * by Oracle in the LICENSE file that accompanied this code.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  */
aoqi@0: 
aoqi@0: package javax.lang.model;
aoqi@0: 
aoqi@0: import java.util.Collections;
aoqi@0: import java.util.Set;
aoqi@0: import java.util.HashSet;
aoqi@0: 
aoqi@0: /**
aoqi@0:  * Source versions of the Java™ programming language.
aoqi@0:  *
aoqi@0:  * See the appropriate edition of
aoqi@0:  * <cite>The Java&trade; Language Specification</cite>
aoqi@0:  * for information about a particular source version.
aoqi@0:  *
aoqi@0:  * <p>Note that additional source version constants will be added to
aoqi@0:  * model future releases of the language.
aoqi@0:  *
aoqi@0:  * @author Joseph D. Darcy
aoqi@0:  * @author Scott Seligman
aoqi@0:  * @author Peter von der Ah&eacute;
aoqi@0:  * @since 1.6
aoqi@0:  */
aoqi@0: public enum SourceVersion {
aoqi@0:     /*
aoqi@0:      * Summary of language evolution
aoqi@0:      * 1.1: nested classes
aoqi@0:      * 1.2: strictfp
aoqi@0:      * 1.3: no changes
aoqi@0:      * 1.4: assert
aoqi@0:      * 1.5: annotations, generics, autoboxing, var-args...
aoqi@0:      * 1.6: no changes
aoqi@0:      * 1.7: diamond syntax, try-with-resources, etc.
aoqi@0:      * 1.8: lambda expressions and default methods
aoqi@0:      */
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * The original version.
aoqi@0:      *
aoqi@0:      * The language described in
aoqi@0:      * <cite>The Java&trade; Language Specification, First Edition</cite>.
aoqi@0:      */
aoqi@0:     RELEASE_0,
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * The version recognized by the Java Platform 1.1.
aoqi@0:      *
aoqi@0:      * The language is {@code RELEASE_0} augmented with nested classes as described in the 1.1 update to
aoqi@0:      * <cite>The Java&trade; Language Specification, First Edition</cite>.
aoqi@0:      */
aoqi@0:     RELEASE_1,
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * The version recognized by the Java 2 Platform, Standard Edition,
aoqi@0:      * v 1.2.
aoqi@0:      *
aoqi@0:      * The language described in
aoqi@0:      * <cite>The Java&trade; Language Specification,
aoqi@0:      * Second Edition</cite>, which includes the {@code
aoqi@0:      * strictfp} modifier.
aoqi@0:      */
aoqi@0:     RELEASE_2,
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * The version recognized by the Java 2 Platform, Standard Edition,
aoqi@0:      * v 1.3.
aoqi@0:      *
aoqi@0:      * No major changes from {@code RELEASE_2}.
aoqi@0:      */
aoqi@0:     RELEASE_3,
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * The version recognized by the Java 2 Platform, Standard Edition,
aoqi@0:      * v 1.4.
aoqi@0:      *
aoqi@0:      * Added a simple assertion facility.
aoqi@0:      */
aoqi@0:     RELEASE_4,
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * The version recognized by the Java 2 Platform, Standard
aoqi@0:      * Edition 5.0.
aoqi@0:      *
aoqi@0:      * The language described in
aoqi@0:      * <cite>The Java&trade; Language Specification,
aoqi@0:      * Third Edition</cite>.  First release to support
aoqi@0:      * generics, annotations, autoboxing, var-args, enhanced {@code
aoqi@0:      * for} loop, and hexadecimal floating-point literals.
aoqi@0:      */
aoqi@0:     RELEASE_5,
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * The version recognized by the Java Platform, Standard Edition
aoqi@0:      * 6.
aoqi@0:      *
aoqi@0:      * No major changes from {@code RELEASE_5}.
aoqi@0:      */
aoqi@0:     RELEASE_6,
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * The version recognized by the Java Platform, Standard Edition
aoqi@0:      * 7.
aoqi@0:      *
aoqi@0:      * Additions in this release include, diamond syntax for
aoqi@0:      * constructors, {@code try}-with-resources, strings in switch,
aoqi@0:      * binary literals, and multi-catch.
aoqi@0:      * @since 1.7
aoqi@0:      */
aoqi@0:     RELEASE_7,
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * The version recognized by the Java Platform, Standard Edition
aoqi@0:      * 8.
aoqi@0:      *
aoqi@0:      * Additions in this release include lambda expressions and default methods.
aoqi@0:      * @since 1.8
aoqi@0:      */
aoqi@0:     RELEASE_8;
aoqi@0: 
aoqi@0:     // Note that when adding constants for newer releases, the
aoqi@0:     // behavior of latest() and latestSupported() must be updated too.
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Returns the latest source version that can be modeled.
aoqi@0:      *
aoqi@0:      * @return the latest source version that can be modeled
aoqi@0:      */
aoqi@0:     public static SourceVersion latest() {
aoqi@0:         return RELEASE_8;
aoqi@0:     }
aoqi@0: 
aoqi@0:     private static final SourceVersion latestSupported = getLatestSupported();
aoqi@0: 
aoqi@0:     private static SourceVersion getLatestSupported() {
aoqi@0:         try {
aoqi@0:             String specVersion = System.getProperty("java.specification.version");
aoqi@0: 
aoqi@0:             if ("1.8".equals(specVersion))
aoqi@0:                 return RELEASE_8;
aoqi@0:             else if("1.7".equals(specVersion))
aoqi@0:                 return RELEASE_7;
aoqi@0:             else if("1.6".equals(specVersion))
aoqi@0:                 return RELEASE_6;
aoqi@0:         } catch (SecurityException se) {}
aoqi@0: 
aoqi@0:         return RELEASE_5;
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Returns the latest source version fully supported by the
aoqi@0:      * current execution environment.  {@code RELEASE_5} or later must
aoqi@0:      * be returned.
aoqi@0:      *
aoqi@0:      * @return the latest source version that is fully supported
aoqi@0:      */
aoqi@0:     public static SourceVersion latestSupported() {
aoqi@0:         return latestSupported;
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Returns whether or not {@code name} is a syntactically valid
aoqi@0:      * identifier (simple name) or keyword in the latest source
aoqi@0:      * version.  The method returns {@code true} if the name consists
aoqi@0:      * of an initial character for which {@link
aoqi@0:      * Character#isJavaIdentifierStart(int)} returns {@code true},
aoqi@0:      * followed only by characters for which {@link
aoqi@0:      * Character#isJavaIdentifierPart(int)} returns {@code true}.
aoqi@0:      * This pattern matches regular identifiers, keywords, and the
aoqi@0:      * literals {@code "true"}, {@code "false"}, and {@code "null"}.
aoqi@0:      * The method returns {@code false} for all other strings.
aoqi@0:      *
aoqi@0:      * @param name the string to check
aoqi@0:      * @return {@code true} if this string is a
aoqi@0:      * syntactically valid identifier or keyword, {@code false}
aoqi@0:      * otherwise.
aoqi@0:      */
aoqi@0:     public static boolean isIdentifier(CharSequence name) {
aoqi@0:         String id = name.toString();
aoqi@0: 
aoqi@0:         if (id.length() == 0) {
aoqi@0:             return false;
aoqi@0:         }
aoqi@0:         int cp = id.codePointAt(0);
aoqi@0:         if (!Character.isJavaIdentifierStart(cp)) {
aoqi@0:             return false;
aoqi@0:         }
aoqi@0:         for (int i = Character.charCount(cp);
aoqi@0:                 i < id.length();
aoqi@0:                 i += Character.charCount(cp)) {
aoqi@0:             cp = id.codePointAt(i);
aoqi@0:             if (!Character.isJavaIdentifierPart(cp)) {
aoqi@0:                 return false;
aoqi@0:             }
aoqi@0:         }
aoqi@0:         return true;
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      *  Returns whether or not {@code name} is a syntactically valid
aoqi@0:      *  qualified name in the latest source version.  Unlike {@link
aoqi@0:      *  #isIdentifier isIdentifier}, this method returns {@code false}
aoqi@0:      *  for keywords and literals.
aoqi@0:      *
aoqi@0:      * @param name the string to check
aoqi@0:      * @return {@code true} if this string is a
aoqi@0:      * syntactically valid name, {@code false} otherwise.
aoqi@0:      * @jls 6.2 Names and Identifiers
aoqi@0:      */
aoqi@0:     public static boolean isName(CharSequence name) {
aoqi@0:         String id = name.toString();
aoqi@0: 
aoqi@0:         for(String s : id.split("\\.", -1)) {
aoqi@0:             if (!isIdentifier(s) || isKeyword(s))
aoqi@0:                 return false;
aoqi@0:         }
aoqi@0:         return true;
aoqi@0:     }
aoqi@0: 
aoqi@0:     private final static Set<String> keywords;
aoqi@0:     static {
aoqi@0:         Set<String> s = new HashSet<String>();
aoqi@0:         String [] kws = {
aoqi@0:             "abstract", "continue",     "for",          "new",          "switch",
aoqi@0:             "assert",   "default",      "if",           "package",      "synchronized",
aoqi@0:             "boolean",  "do",           "goto",         "private",      "this",
aoqi@0:             "break",    "double",       "implements",   "protected",    "throw",
aoqi@0:             "byte",     "else",         "import",       "public",       "throws",
aoqi@0:             "case",     "enum",         "instanceof",   "return",       "transient",
aoqi@0:             "catch",    "extends",      "int",          "short",        "try",
aoqi@0:             "char",     "final",        "interface",    "static",       "void",
aoqi@0:             "class",    "finally",      "long",         "strictfp",     "volatile",
aoqi@0:             "const",    "float",        "native",       "super",        "while",
aoqi@0:             // literals
aoqi@0:             "null",     "true",         "false"
aoqi@0:         };
aoqi@0:         for(String kw : kws)
aoqi@0:             s.add(kw);
aoqi@0:         keywords = Collections.unmodifiableSet(s);
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      *  Returns whether or not {@code s} is a keyword or literal in the
aoqi@0:      *  latest source version.
aoqi@0:      *
aoqi@0:      * @param s the string to check
aoqi@0:      * @return {@code true} if {@code s} is a keyword or literal, {@code false} otherwise.
aoqi@0:      */
aoqi@0:     public static boolean isKeyword(CharSequence s) {
aoqi@0:         String keywordOrLiteral = s.toString();
aoqi@0:         return keywords.contains(keywordOrLiteral);
aoqi@0:     }
aoqi@0: }