duke@1: /*
jjg@1521:  * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
duke@1:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@1:  *
duke@1:  * This code is free software; you can redistribute it and/or modify it
duke@1:  * under the terms of the GNU General Public License version 2 only, as
ohair@554:  * published by the Free Software Foundation.  Oracle designates this
duke@1:  * particular file as subject to the "Classpath" exception as provided
ohair@554:  * by Oracle in the LICENSE file that accompanied this code.
duke@1:  *
duke@1:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@1:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@1:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@1:  * version 2 for more details (a copy is included in the LICENSE file that
duke@1:  * accompanied this code).
duke@1:  *
duke@1:  * You should have received a copy of the GNU General Public License version
duke@1:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@1:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@1:  *
ohair@554:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
ohair@554:  * or visit www.oracle.com if you need additional information or have any
ohair@554:  * questions.
duke@1:  */
duke@1: 
duke@1: package javax.lang.model;
duke@1: 
duke@1: import java.util.Collections;
duke@1: import java.util.Set;
duke@1: import java.util.HashSet;
duke@1: 
duke@1: /**
duke@1:  * Source versions of the Java™ programming language.
duke@1:  *
jjh@972:  * See the appropriate edition of
jjh@972:  * <cite>The Java&trade; Language Specification</cite>
jjh@972:  * for information about a particular source version.
duke@1:  *
duke@1:  * <p>Note that additional source version constants will be added to
duke@1:  * model future releases of the language.
duke@1:  *
duke@1:  * @author Joseph D. Darcy
duke@1:  * @author Scott Seligman
duke@1:  * @author Peter von der Ah&eacute;
duke@1:  * @since 1.6
duke@1:  */
duke@1: public enum SourceVersion {
duke@1:     /*
jjg@1521:      * Summary of language evolution
duke@1:      * 1.1: nested classes
duke@1:      * 1.2: strictfp
duke@1:      * 1.3: no changes
duke@1:      * 1.4: assert
duke@1:      * 1.5: annotations, generics, autoboxing, var-args...
duke@1:      * 1.6: no changes
darcy@1867:      * 1.7: diamond syntax, try-with-resources, etc.
darcy@1867:      * 1.8: lambda expressions and default methods
duke@1:      */
duke@1: 
duke@1:     /**
duke@1:      * The original version.
duke@1:      *
jjh@972:      * The language described in
jjh@972:      * <cite>The Java&trade; Language Specification, First Edition</cite>.
duke@1:      */
duke@1:     RELEASE_0,
duke@1: 
duke@1:     /**
duke@1:      * The version recognized by the Java Platform 1.1.
duke@1:      *
jjh@972:      * The language is {@code RELEASE_0} augmented with nested classes as described in the 1.1 update to
jjh@972:      * <cite>The Java&trade; Language Specification, First Edition</cite>.
duke@1:      */
duke@1:     RELEASE_1,
duke@1: 
duke@1:     /**
duke@1:      * The version recognized by the Java 2 Platform, Standard Edition,
duke@1:      * v 1.2.
duke@1:      *
jjh@972:      * The language described in
jjh@972:      * <cite>The Java&trade; Language Specification,
jjh@972:      * Second Edition</cite>, which includes the {@code
duke@1:      * strictfp} modifier.
duke@1:      */
duke@1:     RELEASE_2,
duke@1: 
duke@1:     /**
duke@1:      * The version recognized by the Java 2 Platform, Standard Edition,
duke@1:      * v 1.3.
duke@1:      *
duke@1:      * No major changes from {@code RELEASE_2}.
duke@1:      */
duke@1:     RELEASE_3,
duke@1: 
duke@1:     /**
duke@1:      * The version recognized by the Java 2 Platform, Standard Edition,
duke@1:      * v 1.4.
duke@1:      *
duke@1:      * Added a simple assertion facility.
duke@1:      */
duke@1:     RELEASE_4,
duke@1: 
duke@1:     /**
duke@1:      * The version recognized by the Java 2 Platform, Standard
duke@1:      * Edition 5.0.
duke@1:      *
jjh@972:      * The language described in
jjh@972:      * <cite>The Java&trade; Language Specification,
jjh@972:      * Third Edition</cite>.  First release to support
duke@1:      * generics, annotations, autoboxing, var-args, enhanced {@code
duke@1:      * for} loop, and hexadecimal floating-point literals.
duke@1:      */
duke@1:     RELEASE_5,
duke@1: 
duke@1:     /**
duke@1:      * The version recognized by the Java Platform, Standard Edition
duke@1:      * 6.
duke@1:      *
duke@1:      * No major changes from {@code RELEASE_5}.
duke@1:      */
duke@1:     RELEASE_6,
duke@1: 
duke@1:     /**
duke@1:      * The version recognized by the Java Platform, Standard Edition
duke@1:      * 7.
duke@1:      *
darcy@1867:      * Additions in this release include, diamond syntax for
darcy@1867:      * constructors, {@code try}-with-resources, strings in switch,
darcy@1867:      * binary literals, and multi-catch.
duke@1:      * @since 1.7
duke@1:      */
darcy@1042:     RELEASE_7,
darcy@1042: 
darcy@1042:     /**
darcy@1042:      * The version recognized by the Java Platform, Standard Edition
darcy@1042:      * 8.
darcy@1042:      *
darcy@1867:      * Additions in this release include lambda expressions and default methods.
darcy@1042:      * @since 1.8
darcy@1042:      */
darcy@1042:     RELEASE_8;
duke@1: 
duke@1:     // Note that when adding constants for newer releases, the
duke@1:     // behavior of latest() and latestSupported() must be updated too.
duke@1: 
duke@1:     /**
duke@1:      * Returns the latest source version that can be modeled.
duke@1:      *
duke@1:      * @return the latest source version that can be modeled
duke@1:      */
duke@1:     public static SourceVersion latest() {
darcy@1042:         return RELEASE_8;
duke@1:     }
duke@1: 
duke@1:     private static final SourceVersion latestSupported = getLatestSupported();
duke@1: 
duke@1:     private static SourceVersion getLatestSupported() {
duke@1:         try {
duke@1:             String specVersion = System.getProperty("java.specification.version");
darcy@1042: 
darcy@1042:             if ("1.8".equals(specVersion))
darcy@1042:                 return RELEASE_8;
darcy@1042:             else if("1.7".equals(specVersion))
duke@1:                 return RELEASE_7;
darcy@1042:             else if("1.6".equals(specVersion))
duke@1:                 return RELEASE_6;
duke@1:         } catch (SecurityException se) {}
duke@1: 
duke@1:         return RELEASE_5;
duke@1:     }
duke@1: 
duke@1:     /**
duke@1:      * Returns the latest source version fully supported by the
duke@1:      * current execution environment.  {@code RELEASE_5} or later must
duke@1:      * be returned.
duke@1:      *
duke@1:      * @return the latest source version that is fully supported
duke@1:      */
duke@1:     public static SourceVersion latestSupported() {
duke@1:         return latestSupported;
duke@1:     }
duke@1: 
duke@1:     /**
duke@1:      * Returns whether or not {@code name} is a syntactically valid
duke@1:      * identifier (simple name) or keyword in the latest source
duke@1:      * version.  The method returns {@code true} if the name consists
duke@1:      * of an initial character for which {@link
duke@1:      * Character#isJavaIdentifierStart(int)} returns {@code true},
duke@1:      * followed only by characters for which {@link
duke@1:      * Character#isJavaIdentifierPart(int)} returns {@code true}.
duke@1:      * This pattern matches regular identifiers, keywords, and the
duke@1:      * literals {@code "true"}, {@code "false"}, and {@code "null"}.
duke@1:      * The method returns {@code false} for all other strings.
duke@1:      *
duke@1:      * @param name the string to check
duke@1:      * @return {@code true} if this string is a
duke@1:      * syntactically valid identifier or keyword, {@code false}
duke@1:      * otherwise.
duke@1:      */
duke@1:     public static boolean isIdentifier(CharSequence name) {
duke@1:         String id = name.toString();
duke@1: 
duke@1:         if (id.length() == 0) {
duke@1:             return false;
duke@1:         }
duke@1:         int cp = id.codePointAt(0);
duke@1:         if (!Character.isJavaIdentifierStart(cp)) {
duke@1:             return false;
duke@1:         }
duke@1:         for (int i = Character.charCount(cp);
duke@1:                 i < id.length();
duke@1:                 i += Character.charCount(cp)) {
duke@1:             cp = id.codePointAt(i);
duke@1:             if (!Character.isJavaIdentifierPart(cp)) {
duke@1:                 return false;
duke@1:             }
duke@1:         }
duke@1:         return true;
duke@1:     }
duke@1: 
duke@1:     /**
duke@1:      *  Returns whether or not {@code name} is a syntactically valid
duke@1:      *  qualified name in the latest source version.  Unlike {@link
duke@1:      *  #isIdentifier isIdentifier}, this method returns {@code false}
duke@1:      *  for keywords and literals.
duke@1:      *
duke@1:      * @param name the string to check
duke@1:      * @return {@code true} if this string is a
duke@1:      * syntactically valid name, {@code false} otherwise.
jjh@972:      * @jls 6.2 Names and Identifiers
duke@1:      */
duke@1:     public static boolean isName(CharSequence name) {
duke@1:         String id = name.toString();
duke@1: 
duke@1:         for(String s : id.split("\\.", -1)) {
duke@1:             if (!isIdentifier(s) || isKeyword(s))
duke@1:                 return false;
duke@1:         }
duke@1:         return true;
duke@1:     }
duke@1: 
duke@1:     private final static Set<String> keywords;
duke@1:     static {
duke@1:         Set<String> s = new HashSet<String>();
duke@1:         String [] kws = {
duke@1:             "abstract", "continue",     "for",          "new",          "switch",
duke@1:             "assert",   "default",      "if",           "package",      "synchronized",
duke@1:             "boolean",  "do",           "goto",         "private",      "this",
duke@1:             "break",    "double",       "implements",   "protected",    "throw",
duke@1:             "byte",     "else",         "import",       "public",       "throws",
duke@1:             "case",     "enum",         "instanceof",   "return",       "transient",
duke@1:             "catch",    "extends",      "int",          "short",        "try",
duke@1:             "char",     "final",        "interface",    "static",       "void",
duke@1:             "class",    "finally",      "long",         "strictfp",     "volatile",
duke@1:             "const",    "float",        "native",       "super",        "while",
duke@1:             // literals
duke@1:             "null",     "true",         "false"
duke@1:         };
duke@1:         for(String kw : kws)
duke@1:             s.add(kw);
duke@1:         keywords = Collections.unmodifiableSet(s);
duke@1:     }
duke@1: 
duke@1:     /**
duke@1:      *  Returns whether or not {@code s} is a keyword or literal in the
duke@1:      *  latest source version.
duke@1:      *
duke@1:      * @param s the string to check
duke@1:      * @return {@code true} if {@code s} is a keyword or literal, {@code false} otherwise.
duke@1:      */
duke@1:     public static boolean isKeyword(CharSequence s) {
duke@1:         String keywordOrLiteral = s.toString();
duke@1:         return keywords.contains(keywordOrLiteral);
duke@1:     }
duke@1: }