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) = .

Start = <sample> List(Basket) EOF.
// what we will have in the composite objects
Pencil = "p" *s.
Fruit : Apple | Orange.
Apple = "a" *s.
Orange = "o" *s.

// The Composite pattern expressed in DemeterF
Composite(S) : Simple(S) | Compound(S).
Simple(S) = <s> S.
Compound(S) = "[" <l> List(Composite(S)) "]".

// Apply the Composite pattern to define Basket 
Basket = "basket" <items> Composite(Item). 
Item : Fruit | Pencil | Basket.

Main = .