134 lines
4.1 KiB
Java
134 lines
4.1 KiB
Java
/*
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* This program and the accompanying materials
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* are made available under the terms of the Eclipse Public License v1.0
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* which accompanies this distribution, and is available at
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* http://www.eclipse.org/legal/epl-v10.html.
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*
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* This file is a derivative of code released by the University of
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* California under the terms listed below.
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*
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* WALA JDT Frontend is Copyright (c) 2008 The Regents of the
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* University of California (Regents). Provided that this notice and
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* the following two paragraphs are included in any distribution of
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* Refinement Analysis Tools or its derivative work, Regents agrees
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* not to assert any of Regents' copyright rights in Refinement
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* Analysis Tools against recipient for recipient's reproduction,
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* preparation of derivative works, public display, public
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* performance, distribution or sublicensing of Refinement Analysis
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* Tools and derivative works, in source code and object code form.
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* This agreement not to assert does not confer, by implication,
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* estoppel, or otherwise any license or rights in any intellectual
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* property of Regents, including, but not limited to, any patents
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* of Regents or Regents' employees.
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*
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* IN NO EVENT SHALL REGENTS BE LIABLE TO ANY PARTY FOR DIRECT,
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* INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES,
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* INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE
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* AND ITS DOCUMENTATION, EVEN IF REGENTS HAS BEEN ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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* REGENTS SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE AND FURTHER DISCLAIMS ANY STATUTORY
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* WARRANTY OF NON-INFRINGEMENT. THE SOFTWARE AND ACCOMPANYING
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* DOCUMENTATION, IF ANY, PROVIDED HEREUNDER IS PROVIDED "AS
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* IS". REGENTS HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT,
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* UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
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*/
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package javaonepointfive;
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// what IS illegal and we don't have to worry about:
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// "x instanceof E"
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// y = new Q();
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interface IGeneric<E> {
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E foo();
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E bar(E x, E y);
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}
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// Y: "implements IGeneric" (no <E>)
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// TOTRY: two arguments
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class ConcreteGeneric<Q> implements IGeneric<Q> {
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Q x;
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public Q bar(Q a, Q b) {
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x = a;
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if (b.hashCode() == a.hashCode() || b.toString().equals(a.toString()))
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return a;
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return b;
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}
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public Q foo() {
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return x;
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}
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}
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class ConcreteGeneric2<Q> extends ConcreteGeneric<Q> {
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Q y;
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public void setFoo(Q a) {
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y = a;
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}
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public Q foo() {
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return y;
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}
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}
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class MyGeneric<A extends Object, B extends IGeneric<A>> {
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A a;
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B b; // TODO: check field type
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public MyGeneric(A a, B b) { // TODO: check parameter type
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this.a = a;
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this.b = b;
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}
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public A doFoo() { // TODO: check return value type
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return b.foo();
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}
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public B getB() {
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return b;
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}
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}
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public class CustomGenericsAndFields {
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static ConcreteGeneric2<String> cg2 = new ConcreteGeneric2<String>();
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static public ConcreteGeneric2<String> cg2WithSideEffects() {
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System.out.println("look at me! I'm a side effect!");
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return cg2;
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}
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public static void main(String args[]) {
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(new CustomGenericsAndFields()).doit();
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}
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private void doit() {
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// Simple: concrete generic
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ConcreteGeneric<String> absinthe = new ConcreteGeneric<String>();
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IGeneric<String> rye = absinthe;
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String foo = rye.bar("hello", "world");
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System.out.println(absinthe.foo() + foo);
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/////////////////////////////
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@SuppressWarnings("unused")
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String thrownaway = cg2.bar("a","b");
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cg2.setFoo("real one");
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MyGeneric<String,ConcreteGeneric2<String>> mygeneric = new MyGeneric<String,ConcreteGeneric2<String>>("useless",cg2);
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String x = mygeneric.doFoo();
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System.out.println(x);
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@SuppressWarnings("unused")
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String y = cg2.x;
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System.out.println(mygeneric.getB().y);
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System.out.println(mygeneric.b.y); // TODO: fields are going to be a pain... watch out for Lvalues in context?
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cg2.x = null;
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cg2.x = "hello";
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// mygeneric.getB().y+="hey"; // TODO: this is going to be a MAJOR pain...
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String real_oneheyya = (((cg2WithSideEffects().y))+="hey")+"ya"; // TODO: this is going to be a MAJOR pain...
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System.out.println(real_oneheyya);
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}
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}
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