001: /*
002: * Copyright 2005-2006 Sun Microsystems, Inc. All Rights Reserved.
003: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004: *
005: * This code is free software; you can redistribute it and/or modify it
006: * under the terms of the GNU General Public License version 2 only, as
007: * published by the Free Software Foundation. Sun designates this
008: * particular file as subject to the "Classpath" exception as provided
009: * by Sun in the LICENSE file that accompanied this code.
010: *
011: * This code is distributed in the hope that it will be useful, but WITHOUT
012: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014: * version 2 for more details (a copy is included in the LICENSE file that
015: * accompanied this code).
016: *
017: * You should have received a copy of the GNU General Public License version
018: * 2 along with this work; if not, write to the Free Software Foundation,
019: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020: *
021: * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022: * CA 95054 USA or visit www.sun.com if you need additional information or
023: * have any questions.
024: */
025:
026: package javax.lang.model.type;
027:
028: import javax.lang.model.element.*;
029: import javax.lang.model.util.Types;
030:
031: /**
032: * Represents a type in the Java programming language.
033: * Types include primitive types, declared types (class and interface types),
034: * array types, type variables, and the null type.
035: * Also represented are wildcard type arguments,
036: * the signature and return types of executables,
037: * and pseudo-types corresponding to packages and to the keyword {@code void}.
038: *
039: * <p> Types should be compared using the utility methods in {@link
040: * Types}. There is no guarantee that any particular type will always
041: * be represented by the same object.
042: *
043: * <p> To implement operations based on the class of an {@code
044: * TypeMirror} object, either use a {@linkplain TypeVisitor visitor}
045: * or use the result of the {@link #getKind} method. Using {@code
046: * instanceof} is <em>not</em> necessarily a reliable idiom for
047: * determining the effective class of an object in this modeling
048: * hierarchy since an implementation may choose to have a single
049: * object implement multiple {@code TypeMirror} subinterfaces.
050: *
051: * @author Joseph D. Darcy
052: * @author Scott Seligman
053: * @author Peter von der Ahé
054: * @version 1.12 07/05/05
055: * @see Element
056: * @see Types
057: * @since 1.6
058: */
059: public interface TypeMirror {
060:
061: /**
062: * Returns the {@code kind} of this type.
063: *
064: * @return the kind of this type
065: */
066: TypeKind getKind();
067:
068: /**
069: * Obeys the general contract of {@link Object#equals Object.equals}.
070: * This method does not, however, indicate whether two types represent
071: * the same type.
072: * Semantic comparisons of type equality should instead use
073: * {@link Types#isSameType(TypeMirror, TypeMirror)}.
074: * The results of {@code t1.equals(t2)} and
075: * {@code Types.isSameType(t1, t2)} may differ.
076: *
077: * @param obj the object to be compared with this type
078: * @return {@code true} if the specified object is equal to this one
079: */
080: boolean equals(Object obj);
081:
082: /**
083: * Obeys the general contract of {@link Object#hashCode Object.hashCode}.
084: *
085: * @see #equals
086: */
087: int hashCode();
088:
089: /**
090: * Returns an informative string representation of this type. If
091: * possible, the string should be of a form suitable for
092: * representing this type in source code. Any names embedded in
093: * the result are qualified if possible.
094: *
095: * @return a string representation of this type
096: */
097: String toString();
098:
099: /**
100: * Applies a visitor to this type.
101: *
102: * @param <R> the return type of the visitor's methods
103: * @param <P> the type of the additional parameter to the visitor's methods
104: * @param v the visitor operating on this type
105: * @param p additional parameter to the visitor
106: * @return a visitor-specified result
107: */
108: <R, P> R accept(TypeVisitor<R, P> v, P p);
109: }
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