From f360a33a1dde8bf3f0c8a03bdb7b8b3d359eec6f Mon Sep 17 00:00:00 2001
From: Nicolas Stucki <nicolas.stucki@gmail.com>
Date: Wed, 22 Nov 2023 15:55:21 +0100
Subject: [PATCH] Cache stable TASTyVersion

---
 tasty/src/dotty/tools/tasty/TastyVersion.scala | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/tasty/src/dotty/tools/tasty/TastyVersion.scala b/tasty/src/dotty/tools/tasty/TastyVersion.scala
index 0d2f1b8c76d8..8bf53c7e7135 100644
--- a/tasty/src/dotty/tools/tasty/TastyVersion.scala
+++ b/tasty/src/dotty/tools/tasty/TastyVersion.scala
@@ -1,6 +1,8 @@
 package dotty.tools.tasty
 
-case class TastyVersion(major: Int, minor: Int, experimental: Int) {
+import scala.collection.mutable
+
+case class TastyVersion private(major: Int, minor: Int, experimental: Int) {
   def isExperimental: Boolean = experimental > 0
 
   def nextStable: TastyVersion = copy(experimental = 0)
@@ -21,4 +23,12 @@ case class TastyVersion(major: Int, minor: Int, experimental: Int) {
     val extra = Option.when(experimental > 0)(this)
     s"stable TASTy from ${min.show} to ${max.show}${extra.fold("")(e => s", or exactly ${e.show}")}"
   }
-}
\ No newline at end of file
+}
+
+object TastyVersion {
+
+  private val cache: mutable.Map[(Int, Int, Int), TastyVersion] = mutable.Map.empty
+
+  def apply(major: Int, minor: Int, experimental: Int): TastyVersion =
+    cache.getOrElseUpdate((major, minor, experimental), new TastyVersion(major, minor, experimental))
+}