From c6cf9110cb739bd1ee43ba49325ece5f9e296e04 Mon Sep 17 00:00:00 2001
From: Peter Aldous <Peter.Aldous@uvu.edu>
Date: Wed, 22 Feb 2023 15:37:25 -0700
Subject: [PATCH 1/2] added equality comparison for Position objects

---
 .../src/main/scala/scala/util/parsing/input/Position.scala | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/shared/src/main/scala/scala/util/parsing/input/Position.scala b/shared/src/main/scala/scala/util/parsing/input/Position.scala
index cb18dc52..688ca63b 100644
--- a/shared/src/main/scala/scala/util/parsing/input/Position.scala
+++ b/shared/src/main/scala/scala/util/parsing/input/Position.scala
@@ -60,4 +60,11 @@ trait Position {
     this.line < that.line ||
     this.line == that.line && this.column < that.column
   }
+
+  /** Compare this position to another, checking for equality.
+   *
+   * @param `that` a `Position` to compare to this `Position`
+   * @return true if the line numbers and column numbers are equal.
+   */
+  def ==(that: Position) = this.line == that.line && this.column == that.column
 }

From 11e08c6037d454b81fc6941437d6bc8edf825b5c Mon Sep 17 00:00:00 2001
From: Peter Aldous <Peter.Aldous@uvu.edu>
Date: Mon, 27 Feb 2023 10:58:51 -0700
Subject: [PATCH 2/2] added a test and changed from == to equals

---
 .../scala/util/parsing/input/Position.scala   |  7 ++-
 .../parsing/combinator/LongestMatchTest.scala | 52 +++++++++++++++++++
 2 files changed, 58 insertions(+), 1 deletion(-)
 create mode 100644 shared/src/test/scala/scala/util/parsing/combinator/LongestMatchTest.scala

diff --git a/shared/src/main/scala/scala/util/parsing/input/Position.scala b/shared/src/main/scala/scala/util/parsing/input/Position.scala
index 688ca63b..e2326829 100644
--- a/shared/src/main/scala/scala/util/parsing/input/Position.scala
+++ b/shared/src/main/scala/scala/util/parsing/input/Position.scala
@@ -66,5 +66,10 @@ trait Position {
    * @param `that` a `Position` to compare to this `Position`
    * @return true if the line numbers and column numbers are equal.
    */
-  def ==(that: Position) = this.line == that.line && this.column == that.column
+  override def equals(other: Any) = {
+    other match {
+      case that: Position => this.line == that.line && this.column == that.column
+      case _ => false
+    }
+  }
 }
diff --git a/shared/src/test/scala/scala/util/parsing/combinator/LongestMatchTest.scala b/shared/src/test/scala/scala/util/parsing/combinator/LongestMatchTest.scala
new file mode 100644
index 00000000..f9dca807
--- /dev/null
+++ b/shared/src/test/scala/scala/util/parsing/combinator/LongestMatchTest.scala
@@ -0,0 +1,52 @@
+package scala.util.parsing.combinator
+
+import java.io.StringReader
+
+import scala.util.parsing.combinator.Parsers
+import scala.util.parsing.input.StreamReader
+
+import org.junit.Test
+import org.junit.Assert.{ assertEquals, fail }
+
+class LongestMatchTest {
+  class TestParsers extends Parsers {
+    type Elem = Char
+
+    def ab: Parser[String] = 'a' ~ 'b' ^^^ "ab"
+    def a: Parser[String] = 'a' ^^^ "a"
+    def ab_alt: Parser[String] = 'a' ~ 'b' ^^^ "alt"
+  }
+
+  @Test
+  def longestMatchFirst: Unit = {
+    val tParsers = new TestParsers
+    val reader = StreamReader(new StringReader("ab"))
+    val p = tParsers.ab ||| tParsers.a
+    p(reader) match {
+      case tParsers.Success(result, _) => assertEquals("ab", result)
+      case _ => fail()
+    }
+  }
+
+  @Test
+  def longestMatchSecond: Unit = {
+    val tParsers = new TestParsers
+    val reader = StreamReader(new StringReader("ab"))
+    val p = tParsers.a ||| tParsers.ab
+    p(reader) match {
+      case tParsers.Success(result, _) => assertEquals("ab", result)
+      case _ => fail()
+    }
+  }
+
+  @Test
+  def tieGoesToFirst: Unit = {
+    val tParsers = new TestParsers
+    val reader = StreamReader(new StringReader("ab"))
+    val p = tParsers.ab ||| tParsers.ab_alt
+    p(reader) match {
+      case tParsers.Success(result, _) => assertEquals("ab", result)
+      case _ => fail()
+    }
+  }
+}