package gen;
import edu.neu.ccs.demeterf.demfgen.lib.*;
import edu.neu.ccs.demeterf.*;

nogen List(X) : Cons(X) | Empty(X).
nogen Cons(X) = <first> X <rest> List(X).
nogen Empty(X) = .

// for Map
extern interface Comparable(X):.
nogen Entry(K:Comparable(K),V) = "(" <key> K *s "->" *s <val> V ")".
 
// This doesn't match the real structure of a Map... but it's fine
//   for Parsing them, as long as the Key is Comparable (Java)
//   or IComparable (C#)
nogen Map(K:Comparable(K),V) = "[" *s <map> RBTree(Entry(K,V)) *s "]".

nogen RBColor: RED | BLACK.
nogen RED = .
nogen BLACK = .
   
nogen RBTree(X:Comparable(X)) : RBNode(X) | RBLeaf(X).
nogen RBNode(X:Comparable(X)) = *s <color> RBColor *s <data> X
    *s <left>  RBTree(X)
    *s <right> RBTree(X) .
nogen RBLeaf(X:Comparable(X)) = .

// illustrate MapReduce
Start = <documents> List(Document) EOF.
Document = "(" 
  // document names don't appear in the output
  <documentName> DocumentName ":"
  <words> List(Word) ")".
Word = <id> ident.
DocumentName = <id> ident.

// IntermediateResult = <pairs> List(Pair). //Pair.c.v=1
// with DemeterF this class is not needed 
// the (w,1) pairs "hang" in the object and are collected
// Pair = <w> Word <c> Count.
// Count = <v> int.
// FinalResult = <map> Map(Word,Integer).

Main = .