Foundations of Software - LAMP - EPFL

The Sequence Combinator
� The sequence combinator P ˜ Q succeeds if P and Q succeed
sequentially, and returns the concatenation of their results.
� ˜ is implemented as a method of class Parser.
abstract class Parser[T] {
def ˜ [U](q : Parser[U]) = new Parser[T ˜ U] {
def apply(in : Input) = Parser.this(in) match {
case Success(x, in1) ⇒
q(in1) match {
case Success(y, in2) ⇒ Success(new ˜(x, y), in2)
case failure ⇒ failure
}
case failure ⇒ failure
}
}
37