Program. Program ::= [Def] ;

DBind. Def ::= Bind ;
DData. Def ::= Data ;
terminator Def ";" ;

Bind. Bind ::= Ident ":" Type ";"
               Ident [Ident] "=" Exp ;

EAnn.   Exp5 ::= "(" Exp ":" Type ")" ;
EId.    Exp4 ::= Ident ;
ELit.   Exp4 ::= Literal ;
EApp.   Exp3 ::= Exp3 Exp4 ;
EAdd.   Exp1 ::= Exp1 "+" Exp2 ;
ELet.   Exp  ::= "let" Ident "=" Exp "in" Exp ; 
EAbs.   Exp  ::= "\\" Ident "." Exp ;
ECase.  Exp ::= "case" Exp "of" "{" [Inj]  "}";

LInt. Literal ::= Integer ;

Inj. Inj ::= Init "=>" Exp ;
terminator Inj ";" ;

InitLit. Init ::= Literal ;
InitConstr. Init ::= Ident [Match] ;
InitCatch. Init ::= "_" ;

LMatch. Match ::= Literal ;
IMatch. Match ::= Ident ;
InitMatch. Match ::= Ident Match ;
separator Match " " ;

TMono. Type1 ::= "_" Ident ;
TPol. Type1 ::= "'" Ident ;
TArr. Type ::= Type1 "->" Type ;
separator Type " " ;

-- shift/reduce problem here
Data. Data ::= "data" Ident [Type] "where" ";"
               [Constructor];

terminator Constructor ";" ;

Constructor. Constructor ::= Ident ":" Type ;

-- This doesn't seem to work so we'll have to live with ugly keywords for now
-- token Poly upper (letter | digit | '_')* ;
-- token Mono lower (letter | digit | '_')* ;

terminator Bind ";" ;
separator Ident " ";

coercions Type 1 ;
coercions Exp 5 ;

comment "--" ;
comment "{-" "-}" ;