java/17 : java.compiler/javax/lang/model/SourceVersion.java

SourceVersion
https://openjdk.java.net/
GPLv2 + Classpath Exception
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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package javax.lang.model;

import java.util.Collections;
import java.util.Set;
import java.util.HashSet;

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, Scott Seligman, Peter von der Ahé
Since: 1.6/**
 * Source versions of the Java programming language.
 *
 * See the appropriate edition of
 * <cite>The Java Language Specification</cite>
 * for information about a particular source version.
 *
 * <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 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
     *   9: modules, small cleanups to 1.7 and 1.8 changes
     *  10: local-variable type inference (var)
     *  11: local-variable syntax for lambda parameters
     *  12: no changes (switch expressions in preview)
     *  13: no changes (switch expressions and text blocks in preview)
     *  14: switch expressions (pattern matching and records in
     *      preview, text blocks in preview again)
     *  15: text blocks (records and pattern matching in preview again)
     */

    The original version.
The language described in
The Java Language Specification, First Edition.
/**
     * The original version.
     *
     * The language described in
     * <cite>The Java Language Specification, First Edition</cite>.
     */
    RELEASE_0,

    The version recognized by the Java Platform 1.1. The language is RELEASE_0 augmented with nested classes as described in the 1.1 update to The Java Language Specification, First Edition.
/**
     * 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
     * <cite>The Java Language Specification, First Edition</cite>.
     */
    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 
strictfp modifier. /**
     * The version recognized by the Java 2 Platform, Standard Edition,
     * v 1.2.
     *
     * The language described in
     * <cite>The Java Language Specification,
     * Second Edition</cite>, 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 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.
/**
     * 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 
for loop, and hexadecimal floating-point literals. /**
     * The version recognized by the Java 2 Platform, Standard
     * Edition 5.0.
     *
     * The language described in
     * <cite>The Java Language Specification,
     * Third Edition</cite>.  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 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, try-with-resources, strings in switch, binary literals, and multi-catch. 
Since: 1.7/**
     * 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/**
     * 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,

    The version recognized by the Java Platform, Standard Edition
9.
Additions in this release include modules and removal of a
single underscore from the set of legal identifier names.
Since: 9/**
     * The version recognized by the Java Platform, Standard Edition
     * 9.
     *
     * Additions in this release include modules and removal of a
     * single underscore from the set of legal identifier names.
     *
     * @since 9
     */
     RELEASE_9,

    The version recognized by the Java Platform, Standard Edition 10. Additions in this release include local-variable type inference (var). 
Since: 10/**
     * The version recognized by the Java Platform, Standard Edition
     * 10.
     *
     * Additions in this release include local-variable type inference
     * ({@code var}).
     *
     * @since 10
     */
    RELEASE_10,

    The version recognized by the Java Platform, Standard Edition
11.
Additions in this release include local-variable syntax for
lambda parameters.
Since: 11/**
     * The version recognized by the Java Platform, Standard Edition
     * 11.
     *
     * Additions in this release include local-variable syntax for
     * lambda parameters.
     *
     * @since 11
     */
    RELEASE_11,

    The version recognized by the Java Platform, Standard Edition
12.
Since: 12/**
     * The version recognized by the Java Platform, Standard Edition
     * 12.
     *
     * @since 12
     */
    RELEASE_12,

    The version recognized by the Java Platform, Standard Edition
13.
Since: 13/**
     * The version recognized by the Java Platform, Standard Edition
     * 13.
     *
     * @since 13
     */
    RELEASE_13,

    The version recognized by the Java Platform, Standard Edition
14.
Additions in this release include switch expressions.
Since: 14/**
     * The version recognized by the Java Platform, Standard Edition
     * 14.
     *
     * Additions in this release include switch expressions.
     *
     * @since 14
     */
    RELEASE_14,

    The version recognized by the Java Platform, Standard Edition
15.
Additions in this release include text blocks.
Since: 15/**
     * The version recognized by the Java Platform, Standard Edition
     * 15.
     *
     * Additions in this release include text blocks.
     *
     * @since 15
     */
    RELEASE_15,

    The version recognized by the Java Platform, Standard Edition
16.
Since: 16/**
     * The version recognized by the Java Platform, Standard Edition
     * 16.
     *
     * @since 16
     */
    RELEASE_16,

    The version recognized by the Java Platform, Standard Edition
17.
Since: 17/**
     * The version recognized by the Java Platform, Standard Edition
     * 17.
     *
     * @since 17
     */
    RELEASE_17;

    // Note that when adding constants for newer releases, the
    // behavior of latest() and latestSupported() must be updated too.

    {@return the latest source version that can be modeled}
/**
     * {@return the latest source version that can be modeled}
     */
    public static SourceVersion latest() {
        return RELEASE_17;
    }

    private static final SourceVersion latestSupported = getLatestSupported();

    /*
     * The integer version to enum constant mapping implemented by
     * this method assumes the JEP 322: "Time-Based Release
     * Versioning" scheme is in effect. This scheme began in JDK
     * 10. If the JDK versioning scheme is revised, this method may
     * need to be updated accordingly.
     */
    private static SourceVersion getLatestSupported() {
        int intVersion = Runtime.version().feature();
        return (intVersion >= 11) ?
            valueOf("RELEASE_" + Math.min(17, intVersion)):
            RELEASE_10;
    }

    {@return the latest source version fully supported by the current execution environment} RELEASE_9 or later must be returned. 
API Note: This method is included alongside latest to allow identification of situations where the language model API is running on a platform version different than the latest version modeled by the API. One way that sort of situation can occur is if an IDE or similar tool is using the API to model source version N while running on platform version
(N - 1). Running in this configuration is
supported by the API. Running an API on platform versions
earlier than (N - 1) or later than N may or may not work as an implementation detail. If an annotation processor was generating code to run under the current execution environment, the processor should only use platform features up to the latestSupported release, which may be earlier than the latest release./**
     * {@return the latest source version fully supported by the
     * current execution environment}  {@code RELEASE_9} or later must
     * be returned.
     *
     * @apiNote This method is included alongside {@link latest} to
     * allow identification of situations where the language model API
     * is running on a platform version different than the latest
     * version modeled by the API. One way that sort of situation can
     * occur is if an IDE or similar tool is using the API to model
     * source version <i>N</i> while running on platform version
     * (<i>N</i>&nbsp;-&nbsp;1). Running in this configuration is
     * supported by the API. Running an API on platform versions
     * earlier than (<i>N</i>&nbsp;-&nbsp;1) or later than <i>N</i>
     * may or may not work as an implementation detail. If an
     * annotation processor was generating code to run under the
     * current execution environment, the processor should only use
     * platform features up to the {@code latestSupported} release,
     * which may be earlier than the {@code latest} release.
     */
    public static SourceVersion latestSupported() {
        return latestSupported;
    }

    Returns whether or not name is a syntactically valid identifier (simple name) or keyword in the latest source version. The method returns true if the name consists of an initial character for which Character.isJavaIdentifierStart(int) returns true, followed only by characters for which Character.isJavaIdentifierPart(int) returns true. This pattern matches regular identifiers, keywords, restricted keywords, restricted identifiers and the literals "true", "false", "null". The method returns false for all other strings. 
Params: name – the string to check
Returns: true if this string is a syntactically valid identifier or keyword, false otherwise.
@jls 3.8 Identifiers/**
     * 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, restricted
     * keywords, restricted identifiers and the literals {@code "true"},
     * {@code "false"}, {@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.
     *
     * @jls 3.8 Identifiers
     */
    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 name is a syntactically valid qualified name in the latest source version. Syntactically, a qualified name is a sequence of identifiers separated by period characters ("."). This method splits the input string into period-separated segments and applies checks to each segment in turn. Unlike isIdentifier, this method returns false for keywords, boolean literals, and the null literal in any segment. This method returns true for restricted
keywords and restricted identifiers.
Params: name – the string to check
Returns: true if this string is a syntactically valid name, false otherwise.
@jls 3.9 Keywords
@jls 6.2 Names and Identifiers/**
     * Returns whether or not {@code name} is a syntactically valid
     * qualified name in the latest source version.
     *
     * Syntactically, a qualified name is a sequence of identifiers
     * separated by period characters ("{@code .}"). This method
     * splits the input string into period-separated segments and
     * applies checks to each segment in turn.
     *
     * Unlike {@link #isIdentifier isIdentifier}, this method returns
     * {@code false} for keywords, boolean literals, and the null
     * literal in any segment.
     *
     * This method returns {@code true} for <i>restricted
     * keywords</i> and <i>restricted identifiers</i>.
     *
     * @param name the string to check
     * @return {@code true} if this string is a
     * syntactically valid name, {@code false} otherwise.
     * @jls 3.9 Keywords
     * @jls 6.2 Names and Identifiers
     */
    public static boolean isName(CharSequence name) {
        return isName(name, latest());
    }

    Returns whether or not name is a syntactically valid qualified name in the given source version. Syntactically, a qualified name is a sequence of identifiers separated by period characters ("."). This method splits the input string into period-separated segments and applies checks to each segment in turn. Unlike isIdentifier, this method returns false for keywords, boolean literals, and the null literal in any segment. This method returns true for restricted
keywords and restricted identifiers.
Params: name – the string to check
version – the version to use
Returns: true if this string is a syntactically valid name, false otherwise.
@jls 3.9 Keywords
@jls 6.2 Names and Identifiers
Since: 9/**
     * Returns whether or not {@code name} is a syntactically valid
     * qualified name in the given source version.
     *
     * Syntactically, a qualified name is a sequence of identifiers
     * separated by period characters ("{@code .}"). This method
     * splits the input string into period-separated segments and
     * applies checks to each segment in turn.
     *
     * Unlike {@link #isIdentifier isIdentifier}, this method returns
     * {@code false} for keywords, boolean literals, and the null
     * literal in any segment.
     *
     * This method returns {@code true} for <i>restricted
     * keywords</i> and <i>restricted identifiers</i>.
     *
     * @param name the string to check
     * @param version the version to use
     * @return {@code true} if this string is a
     * syntactically valid name, {@code false} otherwise.
     * @jls 3.9 Keywords
     * @jls 6.2 Names and Identifiers
     * @since 9
     */
    public static boolean isName(CharSequence name, SourceVersion version) {
        String id = name.toString();

        for(String s : id.split("\\.", -1)) {
            if (!isIdentifier(s) || isKeyword(s, version))
                return false;
        }
        return true;
    }

    Returns whether or not s is a keyword, boolean literal, or null literal in the latest source version. This method returns false for restricted
keywords and restricted identifiers.
Params: s – the string to check
Returns: true if s is a keyword, or boolean literal, or null literal, false otherwise.
@jls 3.9 Keywords
@jls 3.10.3 Boolean Literals
@jls 3.10.8 The Null Literal/**
     * Returns whether or not {@code s} is a keyword, boolean literal,
     * or null literal in the latest source version.
     * This method returns {@code false} for <i>restricted
     * keywords</i> and <i>restricted identifiers</i>.
     *
     * @param s the string to check
     * @return {@code true} if {@code s} is a keyword, or boolean
     * literal, or null literal, {@code false} otherwise.
     * @jls 3.9 Keywords
     * @jls 3.10.3 Boolean Literals
     * @jls 3.10.8 The Null Literal
     */
    public static boolean isKeyword(CharSequence s) {
        return isKeyword(s, latest());
    }

    Returns whether or not s is a keyword, boolean literal, or null literal in the given source version. This method returns false for restricted
keywords and restricted identifiers.
Params: s – the string to check
version – the version to use
Returns: true if s is a keyword, or boolean literal, or null literal, false otherwise.
@jls 3.9 Keywords
@jls 3.10.3 Boolean Literals
@jls 3.10.8 The Null Literal
Since: 9/**
     * Returns whether or not {@code s} is a keyword, boolean literal,
     * or null literal in the given source version.
     * This method returns {@code false} for <i>restricted
     * keywords</i> and <i>restricted identifiers</i>.
     *
     * @param s the string to check
     * @param version the version to use
     * @return {@code true} if {@code s} is a keyword, or boolean
     * literal, or null literal, {@code false} otherwise.
     * @jls 3.9 Keywords
     * @jls 3.10.3 Boolean Literals
     * @jls 3.10.8 The Null Literal
     * @since 9
     */
    public static boolean isKeyword(CharSequence s, SourceVersion version) {
        String id = s.toString();
        switch(id) {
            // A trip through history
        case "strictfp":
            return version.compareTo(RELEASE_2) >= 0;

        case "assert":
            return version.compareTo(RELEASE_4) >= 0;

        case "enum":
            return version.compareTo(RELEASE_5) >= 0;

        case "_":
            return version.compareTo(RELEASE_9) >= 0;

     // case "non-sealed": can be added once it is a keyword only
     // dependent on release and not also preview features being
     // enabled.

            // Keywords common across versions

            // Modifiers
        case "public":    case "protected": case "private":
        case "abstract":  case "static":    case "final":
        case "transient": case "volatile":  case "synchronized":
        case "native":

            // Declarations
        case "class":     case "interface": case "extends":
        case "package":   case "throws":    case "implements":

            // Primitive types and void
        case "boolean":   case "byte":      case "char":
        case "short":     case "int":       case "long":
        case "float":     case "double":
        case "void":

            // Control flow
        case "if":      case "else":
        case "try":     case "catch":    case "finally":
        case "do":      case "while":
        case "for":     case "continue":
        case "switch":  case "case":     case "default":
        case "break":   case "throw":    case "return":

            // Other keywords
        case  "this":   case "new":      case "super":
        case "import":  case "instanceof":

            // Forbidden!
        case "goto":        case "const":

            // literals
        case "null":         case "true":       case "false":
            return true;

        default:
            return false;
        }
    }
}
Author:	Joseph D. Darcy, Scott Seligman, Peter von der Ahé
Since:	1.6
Params:	name – the string to check
Returns:	`true` if this string is a syntactically valid identifier or keyword, `false` otherwise.
@jls	3.8 Identifiers
Params:	name – the string to check version – the version to use
Returns:	`true` if this string is a syntactically valid name, `false` otherwise.
@jls	3.9 Keywords
@jls	6.2 Names and Identifiers
Since:	9
Params:	s – the string to check
Returns:	`true` if `s` is a keyword, or boolean literal, or null literal, `false` otherwise.
@jls	3.9 Keywords
@jls	3.10.3 Boolean Literals
@jls	3.10.8 The Null Literal
Params:	s – the string to check version – the version to use
Returns:	`true` if `s` is a keyword, or boolean literal, or null literal, `false` otherwise.
@jls	3.9 Keywords
@jls	3.10.3 Boolean Literals
@jls	3.10.8 The Null Literal
Since:	9
/

java/ 17/ java.compiler/javax/lang/model/SourceVersion.java
