Mercurial > jdk8-mips64-public > langtools / file revision

 /*

  * Copyright (c) 2005, 2011, 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.util;

 import java.util.List;

 import javax.lang.model.element.*;

 import javax.lang.model.type.*;

 /**

  * Utility methods for operating on types.

  *

  * <p><b>Compatibility Note:</b> Methods may be added to this interface

  * in future releases of the platform.

  *

  * @author Joseph D. Darcy

  * @author Scott Seligman

  * @author Peter von der Ahé

  * @see javax.annotation.processing.ProcessingEnvironment#getTypeUtils

  * @since 1.6

  */

 public interface Types {

     /**

      * Returns the element corresponding to a type.

      * The type may be a {@code DeclaredType} or {@code TypeVariable}.

      * Returns {@code null} if the type is not one with a

      * corresponding element.

      *

      * @return the element corresponding to the given type

      */

     Element asElement(TypeMirror t);

     /**

      * Tests whether two {@code TypeMirror} objects represent the same type.

      *

      * <p>Caveat: if either of the arguments to this method represents a

      * wildcard, this method will return false.  As a consequence, a wildcard

      * is not the same type as itself.  This might be surprising at first,

      * but makes sense once you consider that an example like this must be

      * rejected by the compiler:

      * <pre>

      *   {@code List<?> list = new ArrayList<Object>();}

      *   {@code list.add(list.get(0));}

      * </pre>

      *

      * @param t1  the first type

      * @param t2  the second type

      * @return {@code true} if and only if the two types are the same

      */

     boolean isSameType(TypeMirror t1, TypeMirror t2);

     /**

      * Tests whether one type is a subtype of another.

      * Any type is considered to be a subtype of itself.

      *

      * @param t1  the first type

      * @param t2  the second type

      * @return {@code true} if and only if the first type is a subtype

      *          of the second

      * @throws IllegalArgumentException if given an executable or package type

      * @jls3 4.10 Subtyping

      */

     boolean isSubtype(TypeMirror t1, TypeMirror t2);

     /**

      * Tests whether one type is assignable to another.

      *

      * @param t1  the first type

      * @param t2  the second type

      * @return {@code true} if and only if the first type is assignable

      *          to the second

      * @throws IllegalArgumentException if given an executable or package type

      * @jls3 5.2 Assignment Conversion

      */

     boolean isAssignable(TypeMirror t1, TypeMirror t2);

     /**

      * Tests whether one type argument <i>contains</i> another.

      *

      * @param t1  the first type

      * @param t2  the second type

      * @return {@code true} if and only if the first type contains the second

      * @throws IllegalArgumentException if given an executable or package type

      * @jls3 4.5.1.1 Type Argument Containment and Equivalence

      */

     boolean contains(TypeMirror t1, TypeMirror t2);

     /**

      * Tests whether the signature of one method is a <i>subsignature</i>

      * of another.

      *

      * @param m1  the first method

      * @param m2  the second method

      * @return {@code true} if and only if the first signature is a

      *          subsignature of the second

      * @jls3 8.4.2 Method Signature

      */

     boolean isSubsignature(ExecutableType m1, ExecutableType m2);

     /**

      * Returns the direct supertypes of a type.  The interface types, if any,

      * will appear last in the list.

      *

      * @param t  the type being examined

      * @return the direct supertypes, or an empty list if none

      * @throws IllegalArgumentException if given an executable or package type

      */

     List<? extends TypeMirror> directSupertypes(TypeMirror t);

     /**

      * Returns the erasure of a type.

      *

      * @param t  the type to be erased

      * @return the erasure of the given type

      * @throws IllegalArgumentException if given a package type

      * @jls3 4.6 Type Erasure

      */

     TypeMirror erasure(TypeMirror t);

     /**

      * Returns the class of a boxed value of a given primitive type.

      * That is, <i>boxing conversion</i> is applied.

      *

      * @param p  the primitive type to be converted

      * @return the class of a boxed value of type {@code p}

      * @jls3 5.1.7 Boxing Conversion

      */

     TypeElement boxedClass(PrimitiveType p);

     /**

      * Returns the type (a primitive type) of unboxed values of a given type.

      * That is, <i>unboxing conversion</i> is applied.

      *

      * @param t  the type to be unboxed

      * @return the type of an unboxed value of type {@code t}

      * @throws IllegalArgumentException if the given type has no

      *          unboxing conversion

      * @jls3 5.1.8 Unboxing Conversion

      */

     PrimitiveType unboxedType(TypeMirror t);

     /**

      * Applies capture conversion to a type.

      *

      * @param t  the type to be converted

      * @return the result of applying capture conversion

      * @throws IllegalArgumentException if given an executable or package type

      * @jls3 5.1.10 Capture Conversion

      */

     TypeMirror capture(TypeMirror t);

     /**

      * Returns a primitive type.

      *

      * @param kind  the kind of primitive type to return

      * @return a primitive type

      * @throws IllegalArgumentException if {@code kind} is not a primitive kind

      */

     PrimitiveType getPrimitiveType(TypeKind kind);

     /**

      * Returns the null type.  This is the type of {@code null}.

      *

      * @return the null type

      */

     NullType getNullType();

     /**

      * Returns a pseudo-type used where no actual type is appropriate.

      * The kind of type to return may be either

      * {@link TypeKind#VOID VOID} or {@link TypeKind#NONE NONE}.

      * For packages, use

      * {@link Elements#getPackageElement(CharSequence)}{@code .asType()}

      * instead.

      *

      * @param kind  the kind of type to return

      * @return a pseudo-type of kind {@code VOID} or {@code NONE}

      * @throws IllegalArgumentException if {@code kind} is not valid

      */

     NoType getNoType(TypeKind kind);

     /**

      * Returns an array type with the specified component type.

      *

      * @param componentType  the component type

      * @return an array type with the specified component type.

      * @throws IllegalArgumentException if the component type is not valid for

      *          an array

      */

     ArrayType getArrayType(TypeMirror componentType);

     /**

      * Returns a new wildcard type argument.  Either of the wildcard's

      * bounds may be specified, or neither, but not both.

      *

      * @param extendsBound  the extends (upper) bound, or {@code null} if none

      * @param superBound    the super (lower) bound, or {@code null} if none

      * @return a new wildcard

      * @throws IllegalArgumentException if bounds are not valid

      */

     WildcardType getWildcardType(TypeMirror extendsBound,

                                  TypeMirror superBound);

     /**

      * Returns the type corresponding to a type element and

      * actual type arguments.

      * Given the type element for {@code Set} and the type mirror

      * for {@code String},

      * for example, this method may be used to get the

      * parameterized type {@code Set<String>}.

      *

      * <p> The number of type arguments must either equal the

      * number of the type element's formal type parameters, or must be

      * zero.  If zero, and if the type element is generic,

      * then the type element's raw type is returned.

      *

      * <p> If a parameterized type is being returned, its type element

      * must not be contained within a generic outer class.

      * The parameterized type {@code Outer<String>.Inner<Number>},

      * for example, may be constructed by first using this

      * method to get the type {@code Outer<String>}, and then invoking

      * {@link #getDeclaredType(DeclaredType, TypeElement, TypeMirror...)}.

      *

      * @param typeElem  the type element

      * @param typeArgs  the actual type arguments

      * @return the type corresponding to the type element and

      *          actual type arguments

      * @throws IllegalArgumentException if too many or too few

      *          type arguments are given, or if an inappropriate type

      *          argument or type element is provided

      */

     DeclaredType getDeclaredType(TypeElement typeElem, TypeMirror... typeArgs);

     /**

      * Returns the type corresponding to a type element

      * and actual type arguments, given a

      * {@linkplain DeclaredType#getEnclosingType() containing type}

      * of which it is a member.

      * The parameterized type {@code Outer<String>.Inner<Number>},

      * for example, may be constructed by first using

      * {@link #getDeclaredType(TypeElement, TypeMirror...)}

      * to get the type {@code Outer<String>}, and then invoking

      * this method.

      *

      * <p> If the containing type is a parameterized type,

      * the number of type arguments must equal the

      * number of {@code typeElem}'s formal type parameters.

      * If it is not parameterized or if it is {@code null}, this method is

      * equivalent to {@code getDeclaredType(typeElem, typeArgs)}.

      *

      * @param containing  the containing type, or {@code null} if none

      * @param typeElem    the type element

      * @param typeArgs    the actual type arguments

      * @return the type corresponding to the type element and

      *          actual type arguments, contained within the given type

      * @throws IllegalArgumentException if too many or too few

      *          type arguments are given, or if an inappropriate type

      *          argument, type element, or containing type is provided

      */

     DeclaredType getDeclaredType(DeclaredType containing,

                                  TypeElement typeElem, TypeMirror... typeArgs);

     /**

      * Returns the type of an element when that element is viewed as

      * a member of, or otherwise directly contained by, a given type.

      * For example,

      * when viewed as a member of the parameterized type {@code Set<String>},

      * the {@code Set.add} method is an {@code ExecutableType}

      * whose parameter is of type {@code String}.

      *

      * @param containing  the containing type

      * @param element     the element

      * @return the type of the element as viewed from the containing type

      * @throws IllegalArgumentException if the element is not a valid one

      *          for the given type

      */

     TypeMirror asMemberOf(DeclaredType containing, Element element);

 }