Add three-argument overload for map to Either3

This is a follow-up to eclipse-lsp4j#546
pisv · Apr 21, 2021 · 530713a · 530713a
1 parent 94fd735
commit 530713a
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Showing 3 changed files with 42 additions and 4 deletions.
diff --git a/org.eclipse.lsp4j.jsonrpc/src/main/java/org/eclipse/lsp4j/jsonrpc/messages/Either.java b/org.eclipse.lsp4j.jsonrpc/src/main/java/org/eclipse/lsp4j/jsonrpc/messages/Either.java
@@ -65,7 +65,9 @@ public boolean isRight() {
 		return right != null;
 	}
 
-	public <T> T map(@NonNull Function<? super L, ? extends T> mapLeft, @NonNull Function <? super R, ? extends T> mapRight) {
+	public <T> T map(
+			@NonNull Function<? super L, ? extends T> mapLeft,
+			@NonNull Function<? super R, ? extends T> mapRight) {
 		if (isLeft()) {
 			return mapLeft.apply(getLeft());
 		}

diff --git a/org.eclipse.lsp4j.jsonrpc/src/main/java/org/eclipse/lsp4j/jsonrpc/messages/Either3.java b/org.eclipse.lsp4j.jsonrpc/src/main/java/org/eclipse/lsp4j/jsonrpc/messages/Either3.java
@@ -11,6 +11,8 @@
  ******************************************************************************/
 package org.eclipse.lsp4j.jsonrpc.messages;
 
+import java.util.function.Function;
+
 import org.eclipse.lsp4j.jsonrpc.validation.NonNull;
 
 /**
@@ -81,6 +83,22 @@ public boolean isThird() {
 		return isRight() && getRight().isRight();
 	}
 
+	public <T> T map(
+			@NonNull Function<? super T1, ? extends T> mapFirst,
+			@NonNull Function<? super T2, ? extends T> mapSecond,
+			@NonNull Function<? super T3, ? extends T> mapThird) {
+		if (isFirst()) {
+			return mapFirst.apply(getFirst());
+		}
+		if (isSecond()) {
+			return mapSecond.apply(getSecond());
+		}
+		if (isThird()) {
+			return mapThird.apply(getThird());
+		}
+		return null;
+	}
+
 	@Override
 	public String toString() {
 		StringBuilder builder = new StringBuilder("Either3 [").append(System.lineSeparator());

diff --git a/org.eclipse.lsp4j.jsonrpc/src/test/java/org/eclipse/lsp4j/jsonrpc/test/json/EitherTest.java b/org.eclipse.lsp4j.jsonrpc/src/test/java/org/eclipse/lsp4j/jsonrpc/test/json/EitherTest.java
@@ -16,6 +16,7 @@
 import static org.junit.Assert.assertTrue;
 
 import java.util.Objects;
+import java.util.function.Function;
 
 import org.eclipse.lsp4j.jsonrpc.json.adapters.EitherTypeAdapter;
 import org.eclipse.lsp4j.jsonrpc.messages.Either;
@@ -110,16 +111,33 @@ public void testEqualsFalseWithNonNull() {
 
 	@Test
 	public void testMap() {
-		Either<byte[], String> either =Either.forLeft(new byte[] { 'f', 'o', 'o'});
+		Either<char[], String> either = Either.forLeft(new char[] { 'f', 'o', 'o' });
 		assertEquals("foo", either.map(
 				String::new,
 				String::toUpperCase));
-		either = Either.forRight("barlol");
-		assertEquals("BARLOL", either.map(
+		either = Either.forRight("bar");
+		assertEquals("BAR", either.map(
 				String::new,
 				String::toUpperCase));
 	}
 
+	@Test
+	public void testMapEither3() {
+		Either3<String, Integer, Boolean> either3;
+		Function<String, String> mapFirst = s -> s.toUpperCase();
+		Function<Integer, String> mapSecond = x -> x.toString();
+		Function<Boolean, String> mapThird = b -> b.toString();
+
+		either3 = Either3.forFirst("abc");
+		assertEquals("ABC", either3.map(mapFirst, mapSecond, mapThird));
+
+		either3 = Either3.forSecond(123);
+		assertEquals("123", either3.map(mapFirst, mapSecond, mapThird));
+
+		either3 = Either3.forThird(Boolean.TRUE);
+		assertEquals("true", either3.map(mapFirst, mapSecond, mapThird));
+	}
+
 	protected static class MyObjectA {
 		public Either<String, Integer> myProperty;
 		public String otherProperty;