imports
{
import CommonTypes
import Patterns
import Rules
import UU.Pretty
import UU.Scanner.Position(Pos)
import Expression
}

TYPE Elems     = [Elem]

TYPE Alts      = [Alt]

TYPE SemAlts   = [SemAlt]


DATA AG        | AG     elems  : Elems


DATA Elem      | Data   pos    : {Pos}
                        name   : {Nonterminal}
                        attrs  : Attrs
                        alts   : Alts
                        ext    : {Bool}

               | Type   pos     : {Pos}
                        name    : {Nonterminal}
                        type    : {ComplexType}

               | Attr   pos    : {Pos}
                        names  : NontSet
                        attrs  : Attrs

               | Sem    pos    : {Pos}
                        name   : {Nonterminal}
                        attrs  : Attrs
                        alts   : SemAlts

               | Txt    pos    : {Pos}
                        name   : {Name}
                        lines  : {[String]}
               | Set    pos    : {Pos}
                        name   : {Name}
                        set    : NontSet
               | Deriving pos    : {Pos}
                          set    : NontSet         
                          classes : {[Name]}
               | Wrapper  pos    : {Pos}
                          set    : NontSet         

DATA Attrs     | Attrs  pos    : {Pos}
                        inh,chn,syn : {AttrNames}


DATA Alt       | Alt    pos    : {Pos}
                        name   : {Constructor}
                        fields : {Fields}


DATA SemAlt    | SemAlt pos    : {Pos} 
                        constructorSet   : ConstructorSet
                        rules  : {SemDefs}


DATA ConstructorSet
   | CName name:{Constructor}
   | CUnion set1,set2 : ConstructorSet
   | CDifference set1,set2 : ConstructorSet
   | CAll  

DATA NontSet   | NamedSet name:{Nonterminal}
               | All  
               | Union set1,set2 : NontSet
               | Intersect set1,set2 : NontSet
               | Difference set1,set2 : NontSet
               | Path from,to:{Nonterminal}