build.sbt

@@ -52,7 +52,7 @@ lazy val junit = libraryDependencies += "com.github.sbt" % "junit-interface" % "
 
 lazy val scala211 = "2.11.12"
 lazy val scala212 = "2.12.17"
-lazy val scala213 = "2.13.10"
+lazy val scala213 = "2.13.11"
 lazy val scala3   = "3.2.2"
 
 lazy val compat = new MultiScalaCrossProject(

compat/src/main/scala-2.11_2.12/scala/collection/compat/PackageShared.scala

@@ -564,6 +564,19 @@ class TraversableLikeExtensionMethods[A, Repr](private val self: c.GenTraversabl
     }
     map.toMap
   }
+
+  def distinctBy[B, That](f: A => B)(implicit cbf: CanBuildFrom[Repr, A, That]): That = {
+    val builder = cbf()
+    val keys    = collection.mutable.Set.empty[B]
+    for (element <- self) {
+      val key = f(element)
+      if (!keys.contains(key)) {
+        builder += element
+        keys += key
+      }
+    }
+    builder.result()
+  }
 }
 
 class TrulyTraversableLikeExtensionMethods[El1, Repr1](

compat/src/main/scala-2.11_2.12/scala/util/matching/compat/package.scala

@@ -0,0 +1,30 @@
+/*
+ * Scala (https://www.scala-lang.org)
+ *
+ * Copyright EPFL and Lightbend, Inc.
+ *
+ * Licensed under Apache License 2.0
+ * (http://www.apache.org/licenses/LICENSE-2.0).
+ *
+ * See the NOTICE file distributed with this work for
+ * additional information regarding copyright ownership.
+ */
+
+package scala.util.matching
+
+package object compat {
+  final implicit class RegexOps(val regex: Regex) extends AnyVal {
+
+    /** Returns whether this `Regex` matches the given character sequence.
+     *
+     * Like the extractor, this method takes anchoring into account.
+     *
+     * @param source The text to match against
+     * @return true if and only if `source` matches this `Regex`.
+     * @see [[Regex#unanchored]]
+     * @example {{{"""\d+""".r matches "123" // returns true}}}
+     */
+    def matches(source: CharSequence): Boolean = regex.pattern.matcher(source).matches()
+  }
+
+}

compat/src/main/scala-2.13/scala/util/matching/compat/package.scala

@@ -0,0 +1,18 @@
+/*
+ * Scala (https://www.scala-lang.org)
+ *
+ * Copyright EPFL and Lightbend, Inc.
+ *
+ * Licensed under Apache License 2.0
+ * (http://www.apache.org/licenses/LICENSE-2.0).
+ *
+ * See the NOTICE file distributed with this work for
+ * additional information regarding copyright ownership.
+ */
+
+package scala.util.matching
+
+package object compat {
+  type Regex = scala.util.matching.Regex
+  val Regex = scala.util.matching.Regex
+}

compat/src/test/scala/scala/util/matching/compat/RegexOpsTest.scala

@@ -0,0 +1,26 @@
+/*
+ * Scala (https://www.scala-lang.org)
+ *
+ * Copyright EPFL and Lightbend, Inc.
+ *
+ * Licensed under Apache License 2.0
+ * (http://www.apache.org/licenses/LICENSE-2.0).
+ *
+ * See the NOTICE file distributed with this work for
+ * additional information regarding copyright ownership.
+ */
+
+package scala.util.matching.compat
+
+import org.junit.Assert._
+import org.junit.Test
+
+class RegexOpsTest {
+
+  @Test
+  def testMatches(): Unit = {
+    assertTrue(".*hello.*".r.matches("hey hello"))
+    assertFalse(".*hello.*".r.matches("hey hop"))
+  }
+
+}

compat/src/test/scala/test/scala/collection/CollectionTest.scala

@@ -186,4 +186,11 @@ class CollectionTest {
     assertTrue(List(1, 2, 3).lengthIs >= 2)
     assertTrue(List(1, 2, 3).lengthIs > 2)
   }
+
+  @Test
+  def testDistinctBy(): Unit = {
+    assertEquals(List(1, 2, 3).distinctBy(_   % 2 == 0), List(1, 2))
+    assertEquals(List(3, 1, 2).distinctBy(_   % 2 == 0), List(3, 2))
+    assertEquals(List.empty[Int].distinctBy(_ % 2 == 0), List.empty)
+  }
 }

project/build.properties

@@ -1 +1 @@
-sbt.version=1.8.2
+sbt.version=1.9.0