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object Test extends App {
val a = Map("a" -> Some(1), "b" -> None)
println(a)
// inferred type should be Map[String, Int]
val res = a collect {case (p, Some(a)) => (p, a)}
// variations: const target -> switch, non-const -> normal match, char target --> scrut needs toInt,
// eta-expanded --> work is done by typedFunction, non-eta-expanded --> typedMatch
object nonConstCharEta {
final val GT : Char = 'a'
final val GTGT : Char = 'b'
final val GTGTGT : Char = 'c'
final val GTEQ : Char = 'd'
final val GTGTEQ : Char = 'e'
final val GTGTGTEQ: Char = 'f'
final val ASSIGN : Char = 'g'
def acceptClosingAngle(in: Char) {
val closers: PartialFunction[Char, Char] = {
case GTGTGTEQ => GTGTEQ
case GTGTGT => GTGT
case GTGTEQ => GTEQ
case GTGT => GT
case GTEQ => ASSIGN
}
if (closers isDefinedAt in) println(closers(in))
else println("undefined")
}
def test() = {
acceptClosingAngle(GTGT)
acceptClosingAngle(ASSIGN)
}
}
object nonConstChar {
final val GT : Char = 'a'
final val GTGT : Char = 'b'
final val GTGTGT : Char = 'c'
final val GTEQ : Char = 'd'
final val GTGTEQ : Char = 'e'
final val GTGTGTEQ: Char = 'f'
final val ASSIGN : Char = 'g'
def acceptClosingAngle(in: Char) {
val closers: PartialFunction[Char, Char] = x => x match {
case GTGTGTEQ => GTGTEQ
case GTGTGT => GTGT
case GTGTEQ => GTEQ
case GTGT => GT
case GTEQ => ASSIGN
}
if (closers isDefinedAt in) println(closers(in))
else println("undefined")
}
def test() = {
acceptClosingAngle(GTGT)
acceptClosingAngle(ASSIGN)
}
}
object constCharEta {
final val GT = 'a'
final val GTGT = 'b'
final val GTGTGT = 'c'
final val GTEQ = 'd'
final val GTGTEQ = 'e'
final val GTGTGTEQ= 'f'
final val ASSIGN = 'g'
def acceptClosingAngle(in: Char) {
val closers: PartialFunction[Char, Char] = x => x match {
case GTGTGTEQ => GTGTEQ
case GTGTGT => GTGT
case GTGTEQ => GTEQ
case GTGT => GT
case GTEQ => ASSIGN
}
if (closers isDefinedAt in) println(closers(in))
else println("undefined")
}
def test() = {
acceptClosingAngle(GTGT)
acceptClosingAngle(ASSIGN)
}
}
object constChar {
final val GT = 'a'
final val GTGT = 'b'
final val GTGTGT = 'c'
final val GTEQ = 'd'
final val GTGTEQ = 'e'
final val GTGTGTEQ= 'f'
final val ASSIGN = 'g'
def acceptClosingAngle(in: Char) {
val closers: PartialFunction[Char, Char] = {
case GTGTGTEQ => GTGTEQ
case GTGTGT => GTGT
case GTGTEQ => GTEQ
case GTGT => GT
case GTEQ => ASSIGN
}
if (closers isDefinedAt in) println(closers(in))
else println("undefined")
}
def test() = {
acceptClosingAngle(GTGT)
acceptClosingAngle(ASSIGN)
}
}
object constIntEta {
final val GT = 1
final val GTGT = 2
final val GTGTGT = 3
final val GTEQ = 4
final val GTGTEQ = 5
final val GTGTGTEQ = 6
final val ASSIGN = 7
def acceptClosingAngle(in: Int) {
val closers: PartialFunction[Int, Int] = x => {println("hai!"); (x + 1)} match {
case GTGTGTEQ => GTGTEQ
case GTGTGT => GTGT
case GTGTEQ => GTEQ
case GTGT => GT
case GTEQ => ASSIGN
}
if (closers isDefinedAt in) println(closers(in))
else println("undefined")
}
def test() = {
acceptClosingAngle(GTGT)
acceptClosingAngle(ASSIGN)
}
}
object constInt {
final val GT = 1
final val GTGT = 2
final val GTGTGT = 3
final val GTEQ = 4
final val GTGTEQ = 5
final val GTGTGTEQ = 6
final val ASSIGN = 7
def acceptClosingAngle(in: Int) {
val closers: PartialFunction[Int, Int] = {
case GTGTGTEQ => GTGTEQ
case GTGTGT => GTGT
case GTGTEQ => GTEQ
case GTGT => GT
case GTEQ => ASSIGN
}
if (closers isDefinedAt in) println(closers(in))
else println("undefined")
}
def test() = {
acceptClosingAngle(GTGT)
acceptClosingAngle(ASSIGN)
}
}
println(res) // prints "Map(a -> 1)"
nonConstCharEta.test()
nonConstChar.test()
constCharEta.test()
constChar.test()
constIntEta.test()
constInt.test()
}
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