langtools/src/share/classes/javax/lang/model/SourceVersion.java
changeset 10 06bc494ca11e
child 5520 86e4b9a9da40
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/src/share/classes/javax/lang/model/SourceVersion.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,258 @@
+/*
+ * Copyright 2005-2006 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;
+
+import java.util.Collections;
+import java.util.Set;
+import java.util.HashSet;
+
+/**
+ * Source versions of the Java™ programming language.
+ *
+ * See <a
+ * href="http://java.sun.com/docs/books/jls/">http://java.sun.com/docs/books/jls/</a>
+ * for information on editions of <i>The Java&trade; Language
+ * Specification</i>, including updates and clarifications.
+ *
+ * <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 Ah&eacute;
+ * @since 1.6
+ */
+public enum SourceVersion {
+    /*
+     * Summary of language evoluation
+     * 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 the first edition of <i>The
+     * Java&trade; Language Specification</i>.
+     */
+    RELEASE_0,
+
+    /**
+     * The version recognized by the Java Platform 1.1.
+     *
+     * The language is {@code RELEASE_0} <a
+     * href="http://java.sun.com/docs/books/jls/first_edition/html/1.1Update.html">augmented</a>
+     * with nested classes.
+     */
+    RELEASE_1,
+
+    /**
+     * The version recognized by the Java 2 Platform, Standard Edition,
+     * v 1.2.
+     *
+     * The language described in <i>The Java&trade; Language
+     * Specification, Second Edition</i>, 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 <i>The Java&trade; Language
+     * Specification, Third Edition</i>.  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;
+
+    // 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_7;
+    }
+
+    private static final SourceVersion latestSupported = getLatestSupported();
+
+    private static SourceVersion getLatestSupported() {
+        try {
+            String specVersion = System.getProperty("java.specification.version");
+            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.
+     * @jls3 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);
+    }
+}