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| author | Alexander Kriegisch <Alexander@Kriegisch.name> | 2024-02-01 11:57:10 +0700 |
|---|---|---|
| committer | Alexander Kriegisch <Alexander@Kriegisch.name> | 2024-02-01 11:57:10 +0700 |
| commit | bbe629bc4a5e8c76a0b31686eedc88add5d71360 (patch) | |
| tree | c03cca36ccdd16f37e23ff66c191381a41b5ed8a /docs/adk15notebook/generics.adoc | |
| parent | d6056515f8078572dd35cd091fb31ba48e9d8b53 (diff) | |
| download | aspectj-bbe629bc4a5e8c76a0b31686eedc88add5d71360.tar.gz aspectj-bbe629bc4a5e8c76a0b31686eedc88add5d71360.zip | |
Always use ":leveloffset: +1" with ":doctype: book"
Headlines per ADOC file should start at level 1, not 2. Adjusting the
level offset for books helps to avoid warnings when including book
chapters, but still allows to also use the chapters as stand-alone
documents.
Signed-off-by: Alexander Kriegisch <Alexander@Kriegisch.name>
Diffstat (limited to 'docs/adk15notebook/generics.adoc')
| -rw-r--r-- | docs/adk15notebook/generics.adoc | 38 |
1 files changed, 19 insertions, 19 deletions
diff --git a/docs/adk15notebook/generics.adoc b/docs/adk15notebook/generics.adoc index 8fc99bdbe..404da5514 100644 --- a/docs/adk15notebook/generics.adoc +++ b/docs/adk15notebook/generics.adoc @@ -1,14 +1,14 @@ -== Generics += Generics [[generics-inJava5]] -=== Generics in Java 5 +== Generics in Java 5 This section provides the essential information about generics in Java 5 needed to understand how generics are treated in AspectJ 5. For a full introduction to generics in Java, please see the documentation for the Java 5 SDK. -==== Declaring Generic Types +=== Declaring Generic Types A generic type is declared with one or more type parameters following the type name. By convention formal type parameters are named using a @@ -57,7 +57,7 @@ Some examples follow: with a type that is a subtype of `Number` and that implements `Comparable`. -==== Using Generic and Parameterized Types +=== Using Generic and Parameterized Types You declare a variable (or a method/constructor argument) of a parameterized type by specifying a concrete type specfication for each @@ -132,7 +132,7 @@ more parameterized interfaces (for example, time be a subtype of two interface types which are different parameterizations of the same interface. -==== Subtypes, Supertypes, and Assignability +=== Subtypes, Supertypes, and Assignability The supertype of a generic type `C` is the type given in the extends clause of `C`, or `Object` if no extends clause is present. Given the @@ -163,7 +163,7 @@ example, `List<String>` can be assigned to a variable of type `Collection<?>`, and `List<Double>` can be assigned to a variable of type `List<? extends Number>`. -==== Generic Methods and Constructors +=== Generic Methods and Constructors A static method may be declared with one or more type parameters as in the following declaration: @@ -186,7 +186,7 @@ in a similar fashion: The same technique can be used to declare a generic constructor. -==== Erasure +=== Erasure Generics in Java are implemented using a technique called _erasure_. All type parameter information is erased from the run-time type system. @@ -196,7 +196,7 @@ of type `List<String>`. A consequence of this is that you cannot at runtime ask if an object is an `instanceof` a parameterized type. [[generics-inAspectJ5]] -=== Generics in AspectJ 5 +== Generics in AspectJ 5 AspectJ 5 provides full support for all of the Java 5 language features, including generics. Any legal Java 5 program is a legal AspectJ 5 @@ -205,7 +205,7 @@ parameterized types in pointcuts, inter-type declarations, and declare statements. Parameterized types may freely be used within aspect members, and support is also provided for generic _abstract_ aspects. -==== Matching generic and parameterized types in pointcut expressions +=== Matching generic and parameterized types in pointcut expressions The simplest way to work with generic and parameterized types in pointcut expressions and type patterns is simply to use the raw type @@ -273,7 +273,7 @@ respectively. The members of the generic type `G` can be matched by a signature pattern matching `Object G.myData` and `public List G.getAllDataItems()` respectively. -===== Restricting matching using parameterized types +==== Restricting matching using parameterized types Pointcut matching can be further restricted to match only given parameterizations of parameter types (methods and constructors), return @@ -337,7 +337,7 @@ The execution of `foo` can be matched by `execution(List foo(List))`, `execution(List<Object> foo(List<String>>)` since the erasure of `List<T>` is `List` and not `List<Object>`. -===== Generic wildcards and signature matching +==== Generic wildcards and signature matching When it comes to signature matching, a type parameterized using a generic wildcard is a distinct type. For example, `List<?>` is a very @@ -365,7 +365,7 @@ class C { matches both the execution of `foo` and the execution of `bar` since the upper bound of `List<?>` is implicitly `Object`. -===== Treatment of bridge methods +==== Treatment of bridge methods Under certain circumstances a Java 5 compiler is required to create _bridge methods_ that support the compilation of programs using raw @@ -422,7 +422,7 @@ Object n = new Integer(5); rawType.foo(n); // call to bridge method that would succeed at runtime .... -===== Runtime type matching with this(), target() and args() +==== Runtime type matching with this(), target() and args() The `this()`, `target()`, and `args()` pointcut expressions all match based on the runtime type of their arguments. Because Java 5 implements @@ -591,7 +591,7 @@ aspect A { } .... -===== Binding return values in after returning advice +==== Binding return values in after returning advice After returning advice can be used to bind the return value from a matched join point. AspectJ 5 supports the use of a parameterized type @@ -651,7 +651,7 @@ executes on lists _statically determinable_ to be of the right type by specifying a return type pattern in the associated pointcut. The `@SuppressAjWarnings` annotation can also be used if desired. -===== Declaring pointcuts inside generic types +==== Declaring pointcuts inside generic types Pointcuts can be declared in both classes and aspects. A pointcut declared in a generic type may use the type variables of the type in @@ -692,7 +692,7 @@ public aspect A { } .... -==== Inter-type Declarations +=== Inter-type Declarations AspectJ 5 supports the inter-type declaration of generic methods, and of members on generic types. For generic methods, the syntax is exactly as @@ -743,7 +743,7 @@ declare a member on behalf of (say) `Bar<String>`, you can only declare members on the generic type `Bar<T>`. [[declare-parents-java5]] -==== Declare Parents +=== Declare Parents Both generic and parameterized types can be used as the parent type in a `declare parents` statement (as long as the resulting type hierarchy @@ -758,14 +758,14 @@ statement. since a type cannot implement multiple parameterizations of the same generic interface type. -==== Declare Soft +=== Declare Soft It is an error to use a generic or parameterized type as the softened exception type in a declare soft statement. Java 5 does not permit a generic class to be a direct or indirect subtype of `Throwable` (JLS 8.1.2). -==== Generic Aspects +=== Generic Aspects AspectJ 5 allows an _abstract_ aspect to be declared as a generic type. Any concrete aspect extending a generic abstract aspect must extend a |