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object TestExpressions {
def patmatchScrut {
lazy val z1: Option[String] = { println("forced <z1>"); Some("lazy z1") }
val res = z1 match {
case Some(msg) => msg
case None => "failed"
}
print("lazy val in scrutinee: ")
if (res == "lazy z1")
println("ok")
else
println("failed")
}
def patmatchCase {
val t: Option[String] = Some("test")
val res = t match {
case Some(msg) =>
lazy val z1 = { println("forced <z1>"); "lazy z1" }
z1
case None => "failed"
}
print("lazy val in case: ")
if (res == "lazy z1")
println("ok")
else
println("failed")
}
def patmatchPat {
lazy val Z1 = { println("forced <z1>"); "lazy Z1" }
print("lazy val in case: ")
val t: Option[String] = Some("lazy Z1")
t match {
case Some(Z1) =>
println("ok")
case None =>
println("failed")
}
}
def ifcond {
lazy val z1 = { println("forced <z1>"); "lazy z1" }
print("lazy val in if condition: ")
if (z1 == "lazy z1")
println("ok")
else
println("failed")
}
lazy val LazyField = { println("forced LazyField"); "LazyField" }
def testPatMatchField {
print("lazy val in pattern: ")
val t: Option[String] = Some("LazyField")
t match {
case Some(LazyField) =>
println("ok")
case None =>
println("failed")
}
}
lazy val (x, y) = ({print("x"); "x"}, {print("y"); "y"})
def testPatLazyVal {
println("lazy val with patterns:")
print("x and y: ")
println("(" + x + ", " + y + ")")
lazy val (x1, y1) = ({print("x1"); "x1"}, {print("y1"); "y1"})
print("x1 and y1: ")
println("(" + x1 + ", " + y1 + ")")
}
def test {
patmatchScrut
patmatchCase
patmatchPat
ifcond
testPatMatchField
testPatLazyVal
}
}
object Test extends App {
TestExpressions.test
}
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