javax.lang.model.SourceVersion Maven / Gradle / Ivy
/*
* Copyright (C) 2021 ZeoFlow SRL
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package javax.lang.model;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;
/**
* Source versions of the Java™ programming language.
*
* See the appropriate edition of
* The Java™ Language Specification
* for information about a particular source version.
*
*
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
* 1.7: diamond syntax, try-with-resources, etc.
* 1.8: lambda expressions and default methods
*/
/**
* The original version.
*
* The language described in
* The Java™ Language Specification, First Edition.
*/
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
* The Java™ Language Specification, First Edition.
*/
RELEASE_1,
/**
* The version recognized by the Java 2 Platform, Standard Edition,
* v 1.2.
*
* The language described in
* The Java™ Language Specification,
* Second Edition, 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
* The Java™ Language Specification,
* Third Edition. 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.
*
* Additions in this release include, diamond syntax for
* constructors, {@code try}-with-resources, strings in switch,
* binary literals, and multi-catch.
*
* @since 1.7
*/
RELEASE_7,
/**
* The version recognized by the Java Platform, Standard Edition
* 8.
*
* Additions in this release include lambda expressions and default methods.
*
* @since 1.8
*/
RELEASE_8;
// Note that when adding constants for newer releases, the
// behavior of latest() and latestSupported() must be updated too.
private static final SourceVersion latestSupported = getLatestSupported();
private final static Set keywords;
static
{
Set s = new HashSet();
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 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 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.
*/
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;
}
/**
* 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);
}
}