Require default for finite domains instead of giving up (#653)

Should fix #652
effekt-lang · Oct 25, 2024 · 70cfba8 · 70cfba8
1 parent cd7e44f
commit 70cfba8
Show file tree

Hide file tree

Showing 4 changed files with 14 additions and 1 deletion.
diff --git a/effekt/shared/src/main/scala/effekt/typer/ExhaustivityChecker.scala b/effekt/shared/src/main/scala/effekt/typer/ExhaustivityChecker.scala
@@ -259,7 +259,10 @@ object ExhaustivityChecker {
           cases.foreach { v =>
             matches.get(v) match {
               case Some(head :: tail) => matchClauses(head, tail)
-              case _ => E.missingLiteral(v, tpe, scrutinee)
+              case _ => defaults.toList match {
+                case Nil => E.missingLiteral(v, tpe, scrutinee)
+                case head :: tail => matchClauses(head, tail)
+              }
             }
           }
 

diff --git a/examples/pos/issue652.check b/examples/pos/issue652.check
diff --git a/examples/pos/issue652.effek b/examples/pos/issue652.effek
@@ -0,0 +1,4 @@
+def foo(opt: Option[Bool]) = opt match {
+  case Some(false) => Some(false)
+  case opt => Some(true)
+}
diff --git a/examples/pos/issue652.effekt b/examples/pos/issue652.effekt
@@ -0,0 +1,6 @@
+def foo(opt: Option[Bool]) = opt match {
+  case Some(false) => Some(false)
+  case opt => Some(true)
+}
+
+def main() = ()