From 891862ccbc48d58647355aab2618c2a76bc7502e Mon Sep 17 00:00:00 2001
From: kenji yoshida <6b656e6a69@gmail.com>
Date: Tue, 26 Dec 2023 12:14:17 +0900
Subject: [PATCH] add `case` in for comprehension. prepare Scala 3.4

https://github.com/lampepfl/dotty/commit/849ee9c07cf16f7199ab58348540c169eaa4dcac

```
Welcome to Scala 3.4.0-RC1 (1.8.0_392, Java OpenJDK 64-Bit Server VM).
Type in expressions for evaluation. Or try :help.

scala> for((f, true) <- List.empty[(Int, Boolean)]) yield f
-- Error: ----------------------------------------------------------------------
1 |for((f, true) <- List.empty[(Int, Boolean)]) yield f
  |        ^^^^
  |pattern's type (true : Boolean) is more specialized than the right hand side expression's type Boolean
  |
  |If the narrowing is intentional, this can be communicated by adding the `case` keyword before the full pattern,
  |which will result in a filtering for expression (using `withFilter`).
1 error found
```

```
Welcome to Scala 3.3.1 (1.8.0_392, Java OpenJDK 64-Bit Server VM).
Type in expressions for evaluation. Or try :help.

scala> for((f, true) <- List.empty[(Int, Boolean)]) yield f
1 warning found
-- Warning: --------------------------------------------------------------------
1 |for((f, true) <- List.empty[(Int, Boolean)]) yield f
  |        ^^^^
  |pattern's type (true : Boolean) is more specialized than the right hand side expression's type Boolean
  |
  |If the narrowing is intentional, this can be communicated by adding the `case` keyword before the full pattern,
  |which will result in a filtering for expression (using `withFilter`).
val res0: List[Int] = List()
```
---
 io/src/main/scala/sbt/io/IO.scala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io/src/main/scala/sbt/io/IO.scala b/io/src/main/scala/sbt/io/IO.scala
index bdd28035..802f98ae 100644
--- a/io/src/main/scala/sbt/io/IO.scala
+++ b/io/src/main/scala/sbt/io/IO.scala
@@ -558,7 +558,7 @@ object IO {
       isEmpty.getOrElseUpdate(f, dirs(f) && f.isDirectory && (f.listFiles forall visit))
 
     dirs foreach visit
-    for ((f, true) <- isEmpty) f.delete
+    for (case (f, true) <- isEmpty) f.delete
   }
 
   /** Deletes each file or directory (recursively) in `files`. */