parser3.scala
changeset 92 e85600529ca5
parent 91 47f86885d481
child 93 4794759139ea
--- a/parser3.scala	Sun Dec 23 00:38:56 2012 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,41 +0,0 @@
-package object parser {
-
-// parser combinators 
-// with input type I and return type T
-//
-// needs to be compiled with scalac parser3.scala
-
-abstract class Parser[I <% Seq[_], T] {
-  def parse(ts: I): Set[(T, I)]
-
-  def parse_all(ts: I) : Set[T] =
-    for ((head, tail) <- parse(ts); if (tail.isEmpty)) yield head
-
-  def parse_single(ts: I) : T = parse_all(ts).toList match {
-    case t::Nil => t
-    case _ => { println ("Parse Error") ; sys.exit(-1) }
-  }
-    
-  def || (right : => Parser[I, T]) : Parser[I, T] = new AltParser(this, right)
-  def ==>[S] (f: => T => S) : Parser [I, S] = new FunParser(this, f)
-  def ~[S] (right : => Parser[I, S]) : Parser[I, (T, S)] = new SeqParser(this, right)
-  def ~>[S] (right : => Parser[I, S]) : Parser[I, S] = this ~ right ==> (_._2)
-  def <~[S] (right : => Parser[I, S]) : Parser[I, T] = this ~ right ==> (_._1)
-}
-
-class SeqParser[I <% Seq[_], T, S](p: => Parser[I, T], q: => Parser[I, S]) extends Parser[I, (T, S)] {
-  def parse(sb: I) = 
-    for ((head1, tail1) <- p.parse(sb); 
-         (head2, tail2) <- q.parse(tail1)) yield ((head1, head2), tail2)
-}
-
-class AltParser[I <% Seq[_], T](p: => Parser[I, T], q: => Parser[I, T]) extends Parser[I, T] {
-  def parse(sb: I) = p.parse(sb) ++ q.parse(sb)   
-}
-
-class FunParser[I <% Seq[_], T, S](p: => Parser[I, T], f: T => S) extends Parser[I, S] {
-  def parse(sb: I) = 
-    for ((head, tail) <- p.parse(sb)) yield (f(head), tail)
-}
-
-}