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/*
* Copyright (c) 2005, 2006, 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 <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™ 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 Ahé
* @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™ 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™ 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™ 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);
}
}
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