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/*
* Copyright (c) 2017, 2022, 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.
*
* 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.
*/
/*
* @test
* @bug 8262891 8268663 8289894
* @summary Check guards implementation.
*/
import java.util.Objects;
import java.util.function.Function;
public class Guards {
public static void main(String... args) {
new Guards().run();
}
void run() {
run(this::typeTestPatternSwitchTest);
run(this::typeTestPatternSwitchExpressionTest);
run(this::testBooleanSwitchExpression);
assertEquals("a", testPatternInGuard("a"));
assertEquals(null, testPatternInGuard(1));
runIfTrue(this::typeGuardIfTrueIfStatement);
runIfTrue(this::typeGuardIfTrueSwitchExpression);
runIfTrue(this::typeGuardIfTrueSwitchStatement);
runIfTrue(this::typeGuardAfterParenthesizedTrueSwitchStatement);
runIfTrue(this::typeGuardAfterParenthesizedTrueSwitchExpression);
runIfTrue(this::typeGuardAfterParenthesizedTrueIfStatement);
}
void run(Function<Object, String> convert) {
assertEquals("zero", convert.apply(0));
assertEquals("one", convert.apply(1));
assertEquals("other", convert.apply(-1));
assertEquals("box with empty", convert.apply(new Box("")));
assertEquals("box with non-empty", convert.apply(new Box("a")));
assertEquals("any", convert.apply(""));
}
void runIfTrue(Function<Object, String> convert) {
assertEquals("true", convert.apply(0));
assertEquals("second", convert.apply(2));
assertEquals("any", convert.apply(""));
}
String typeTestPatternSwitchTest(Object o) {
switch (o) {
case Integer i when i == 0: return "zero";
case Integer i when i == 1: return "one";
case Integer i: return "other";
case Box(String s) when s.isEmpty(): return "box with empty";
case Box(String s) : return "box with non-empty";
case Object x: return "any";
}
}
String typeTestPatternSwitchExpressionTest(Object o) {
return switch (o) {
case Integer i when i == 0 -> "zero";
case Integer i when i == 1 -> { yield "one"; }
case Integer i -> "other";
case Box(String s) when s.isEmpty() -> "box with empty";
case Box(String s) -> "box with non-empty";
case Object x -> "any";
};
}
String testBooleanSwitchExpression(Object o) {
String x;
if (switch (o) {
case Integer i when i == 0 -> (x = "zero") != null;
case Integer i when i == 1 -> { x = "one"; yield true; }
case Integer i -> { x = "other"; yield true; }
case Box(String s) when s.isEmpty() -> {x = "box with empty"; yield true; }
case Box(String s) -> {x = "box with non-empty"; yield true; }
case Object other -> (x = "any") != null;
}) {
return x;
} else {
throw new IllegalStateException("TODO - needed?");
}
}
String typeGuardIfTrueSwitchStatement(Object o) {
Object o2 = "";
switch (o) {
case Integer i when i == 0 && i < 1 && o2 instanceof String s: o = s + String.valueOf(i); return "true";
case Integer i when i == 0 || i > 1: o = String.valueOf(i); return "second";
case Object x: return "any";
}
}
String typeGuardIfTrueSwitchExpression(Object o) {
Object o2 = "";
return switch (o) {
case Integer i when i == 0 && i < 1 && o2 instanceof String s: o = s + String.valueOf(i); yield "true";
case Integer i when i == 0 || i > 1: o = String.valueOf(i); yield "second";
case Object x: yield "any";
};
}
String typeGuardIfTrueIfStatement(Object o) {
Object o2 = "";
if (o != null && o instanceof Integer i && i == 0 && i < 1 && (o = i) != null && o2 instanceof String s) {
return s != null ? "true" : null;
} else if (o != null && o instanceof Integer i && (i == 0 || i > 1) && (o = i) != null) {
return "second";
} else {
return "any";
}
}
String typeGuardAfterParenthesizedTrueSwitchStatement(Object o) {
switch (o) {
case Integer i when i == 0: o = String.valueOf(i); return "true";
case Integer i when i == 2: o = String.valueOf(i); return "second";
case Object x: return "any";
}
}
String typeGuardAfterParenthesizedTrueSwitchExpression(Object o) {
return switch (o) {
case Integer i when i == 0: o = String.valueOf(i); yield "true";
case Integer i when i == 2: o = String.valueOf(i); yield "second";
case Object x: yield "any";
};
}
String typeGuardAfterParenthesizedTrueIfStatement(Object o) {
if (o != null && o instanceof Integer i && i == 0) {
return "true";
} else if (o != null && o instanceof Integer i && i == 2 && (o = i) != null) {
return "second";
} else {
return "any";
}
}
String testPatternInGuard(Object o) {
if (o instanceof CharSequence cs && cs instanceof String s) {
return s;
}
return null;
}
record Box(Object o) {}
void assertEquals(String expected, String actual) {
if (!Objects.equals(expected, actual)) {
throw new AssertionError("Expected: " + expected + ", but got: " + actual);
}
}
}
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