Another test

Author: odersky

tests/run/errorhandling.check

@@ -0,0 +1,4 @@
+breakTest
+optTest
+resultTest
+Person(Kostas,5)

tests/run/errorhandling/Test.scala

@@ -66,4 +66,5 @@ def resultTest() =
 @main def Test =
   breakTest()
   optTest()
-  resultTest()
+  resultTest()
+  parseCsvIgnoreErrors()

tests/run/errorhandling/break.scala

@@ -11,8 +11,9 @@ object boundary:
   transparent inline def apply[T <: R, R](inline body: Label[T] ?=> R): R =
     val local = Label[T]()
     try body(using local)
-    catch case ex: Break[T] @unchecked if ex.label eq local =>
-      ex.value
+    catch case ex: Break[T] @unchecked =>
+      if ex.label eq local then ex.value
+      else throw ex
 
 end boundary
 

tests/run/errorhandling/kostas.scala

@@ -0,0 +1,35 @@
+package optionMockup:
+  import dotty.util.boundary
+  object optional:
+    transparent inline def apply[T](inline body: boundary.Label[None.type] ?=> T): Option[T] =
+      boundary(Some(body))
+
+  extension [T](r: Option[T])
+    transparent inline def ? (using label: boundary.Label[None.type]): T = r match
+      case Some(x) => x
+      case None => label.break(None)
+
+import optionMockup.*
+
+case class Person(name: String, age: Int)
+
+object PersonCsvParserIgnoreErrors:
+  def parse(csv: Seq[String]): Seq[Person] =
+    for
+      line <- csv
+      columns = line.split(",")x
+      parsed <- parseColumns(columns)
+    yield
+      parsed
+
+  private def parseColumns(columns: Seq[String]): Option[Person] =
+    columns match
+      case Seq(name, age) => parsePerson(name, age)
+      case _              => None
+
+  private def parsePerson(name: String, age: String): Option[Person] =
+    optional:
+      Person(name, age.toIntOption.?)
+
+def parseCsvIgnoreErrors() =
+  println(PersonCsvParserIgnoreErrors.parse(Seq("Kostas,5", "George,invalid", "too,many,columns")).mkString("\n"))