--- /dev/null
+import java.awt.*;
+import java.util.List;
+import java.util.PriorityQueue;
+import java.util.Queue;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+/**
+ * Examples taken from <a href="https://openjdk.org/jeps/443">JEP 443</a>
+ */
+public class UnnamedPatternsPreview1 {
+ public static void main(String[] args) {
+ // An enhanced for loop with side effects
+ int acc = 0;
+ final int LIMIT = 2;
+ for (Order _ : List.of(new Order(), new Order(), new Order())) {
+ if (acc < LIMIT)
+ acc++;
+ }
+ System.out.println(acc);
+
+ // The initialisation of a basic for loop can declare unnamed local variables
+ for (int i = 0, _ = sideEffect(); i < 2; i++) {
+ System.out.println(i);
+ }
+
+ // An assignment statement, where the result of the expression on the right hand side is not needed
+ Queue<Integer> q = new PriorityQueue<>(List.of(1, 2, 3, 4, 5, 6));
+ while (q.size() >= 3) {
+ var x = q.remove();
+ var y = q.remove();
+ var _ = q.remove();
+ System.out.println(new Point(x, y));
+ }
+
+ // The same unnamed variable name '_' can be used in multiple assignment statements
+ q = new PriorityQueue<>(List.of(1, 2, 3, 4, 5, 6));
+ while (q.size() >= 3) {
+ var x = q.remove();
+ var _ = q.remove();
+ var _ = q.remove();
+ System.out.println(new Point(x, 0));
+ }
+
+ // Unnamed variables can be used in one or multiple catch blocks
+ String s = "123xy";
+ try {
+ int i = Integer.parseInt(s);
+ System.out.println(i);
+ } catch (NumberFormatException _) {
+ System.out.println("Bad number: " + s);
+ } catch (Exception _) {
+ System.out.println("Unexpected error");
+ }
+
+ // Try with resources
+ try (var _ = ScopedContext.acquire()) {
+ System.out.println("Doing something within scoped context");
+ }
+
+ // A lambda whose parameter is irrelevant
+ System.out.println(
+ Stream.of("one", "two", "three")
+ .collect(Collectors.toMap(String::toUpperCase, _ -> "NODATA"))
+ );
+ }
+
+ static int sideEffect() {
+ System.out.println("side effect");
+ return 42;
+ }
+
+ static class Order {}
+
+ static class ScopedContext implements AutoCloseable {
+ public static ScopedContext acquire() {
+ return new ScopedContext();
+ }
+
+ @Override
+ public void close() {
+ System.out.println("Closing scoped context");
+ }
+ }
+}
--- /dev/null
+import java.awt.*;
+import java.util.List;
+import java.util.PriorityQueue;
+import java.util.Queue;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+/**
+ * Examples taken from <a href="https://openjdk.org/jeps/443">JEP 443</a>
+ */
+public class UnnamedPatternsPreview1Aspect {
+ public static void main(String[] args) {}
+
+ before() : execution(* main(String[])) {
+ System.out.println(thisJoinPoint);
+
+ // An enhanced for loop with side effects
+ int acc = 0;
+ final int LIMIT = 2;
+ for (Order _ : List.of(new Order(), new Order(), new Order())) {
+ if (acc < LIMIT)
+ acc++;
+ }
+ System.out.println(acc);
+
+ // The initialisation of a basic for loop can declare unnamed local variables
+ for (int i = 0, _ = sideEffect(); i < 2; i++) {
+ System.out.println(i);
+ }
+
+ // An assignment statement, where the result of the expression on the right hand side is not needed
+ Queue<Integer> q = new PriorityQueue<>(List.of(1, 2, 3, 4, 5, 6));
+ while (q.size() >= 3) {
+ var x = q.remove();
+ var y = q.remove();
+ var _ = q.remove();
+ System.out.println(new Point(x, y));
+ }
+
+ // The same unnamed variable name '_' can be used in multiple assignment statements
+ q = new PriorityQueue<>(List.of(1, 2, 3, 4, 5, 6));
+ while (q.size() >= 3) {
+ var x = q.remove();
+ var _ = q.remove();
+ var _ = q.remove();
+ System.out.println(new Point(x, 0));
+ }
+
+ // Unnamed variables can be used in one or multiple catch blocks
+ String s = "123xy";
+ try {
+ int i = Integer.parseInt(s);
+ System.out.println(i);
+ } catch (NumberFormatException _) {
+ System.out.println("Bad number: " + s);
+ } catch (Exception _) {
+ System.out.println("Unexpected error");
+ }
+
+ // Try with resources
+ try (var _ = ScopedContext.acquire()) {
+ System.out.println("Doing something within scoped context");
+ }
+
+ // A lambda whose parameter is irrelevant
+ System.out.println(
+ Stream.of("one", "two", "three")
+ .collect(Collectors.toMap(String::toUpperCase, _ -> "NODATA"))
+ );
+ }
+
+ static int sideEffect() {
+ System.out.println("side effect");
+ return 42;
+ }
+
+ static class Order {}
+
+ static class ScopedContext implements AutoCloseable {
+ public static ScopedContext acquire() {
+ return new ScopedContext();
+ }
+
+ @Override
+ public void close() {
+ System.out.println("Closing scoped context");
+ }
+ }
+}
runTest("string patterns aspect");
}
+ /**
+ * Still not implemented with the Java 21 release Eclipse 2023-12 (4.30),
+ * see <a href="https://github.com/eclipse-jdt/eclipse.jdt.core/issues/893">GitHub issue 893</a>.
+ * <p>
+ * TODO: Activate after JDT Core implementation and merge.
+ */
+ public void testUnnamedPatterns() {
+ //runTest("unnamed patterns");
+ System.out.println("Unnamed patterns still are not implemented with the Java 21 release Eclipse 2023-12 (4.30)");
+ }
+
+ /**
+ * Still not implemented with the Java 21 release Eclipse 2023-12 (4.30),
+ * see <a href="https://github.com/eclipse-jdt/eclipse.jdt.core/issues/893">GitHub issue 893</a>.
+ * <p>
+ * TODO: Activate after JDT Core implementation and merge.
+ */
+ public void testUnnamedPatternsAspect() {
+ //runTest("unnamed patterns aspect");
+ System.out.println("Unnamed patterns still are not implemented with the Java 21 release Eclipse 2023-12 (4.30)");
+ }
+
public static Test suite() {
return XMLBasedAjcTestCase.loadSuite(Java21PreviewFeaturesTests.class);
}
</run>
</ajc-test>
+ <!-- Java 21 preview -->
+ <!-- TODO: Activate after https://github.com/eclipse-jdt/eclipse.jdt.core/issues/893 is done -->
+ <ajc-test dir="features1921/java21" vm="21" title="unnamed patterns">
+ <compile files="UnnamedPatternsPreview1.java" options="--enable-preview -21"/>
+ <run class="UnnamedPatternsPreview1" vmargs="--enable-preview">
+ <stdout ordered="yes">
+ <line text="0"/>
+ <line text="1"/>
+ <line text="java.awt.Point[x=1,y=2]"/>
+ <line text="java.awt.Point[x=4,y=5]"/>
+ <line text="java.awt.Point[x=1,y=0]"/>
+ <line text="java.awt.Point[x=4,y=0]"/>
+ <line text="Bad number: 123xy"/>
+ <line text="Doing something within scoped context"/>
+ <line text="Closing scoped context"/>
+ <line text="{ONE=NODATA, TWO=NODATA, THREE=NODATA}"/>
+ </stdout>
+ </run>
+ </ajc-test>
+
+ <!-- Java 21 preview -->
+ <!-- TODO: Activate after https://github.com/eclipse-jdt/eclipse.jdt.core/issues/893 is done -->
+ <ajc-test dir="features1921/java21" vm="21" title="unnamed patterns aspect">
+ <compile files="UnnamedPatternsPreview1Aspect.java" options="--enable-preview -21"/>
+ <run class="UnnamedPatternsPreview1Aspect" vmargs="--enable-preview">
+ <stdout ordered="yes">
+ <line text="execution(void UnnamedPatternsPreview1Aspect.main(String[]))"/>
+ <line text="0"/>
+ <line text="1"/>
+ <line text="java.awt.Point[x=1,y=2]"/>
+ <line text="java.awt.Point[x=4,y=5]"/>
+ <line text="java.awt.Point[x=1,y=0]"/>
+ <line text="java.awt.Point[x=4,y=0]"/>
+ <line text="Bad number: 123xy"/>
+ <line text="Doing something within scoped context"/>
+ <line text="Closing scoped context"/>
+ <line text="{ONE=NODATA, TWO=NODATA, THREE=NODATA}"/>
+ </stdout>
+ </run>
+ </ajc-test>
+
</suite>
projects / aspectj.git / commitdiff