open Lexer type syntree = Term of char list | NonTerm of char list | Param of char list | Opt of syntree | Rep of syntree | TermRep of syntree * syntree | OptRep of syntree | OrList of syntree list | Con of syntree * syntree let analyse str = let rec rexp s = let mid = parser [< 'MID >] -> () in let rec restrexp e1 = parser [< _ = mid; e2 = andrexp; e = restrexp (match e1 with OrList l -> OrList (l @ [e2]) | _ -> OrList [e1; e2] ) >] -> e | [< >] -> e1 in match s with parser [< e1 = andrexp; e2 = restrexp e1 >] -> e2 and andrexp s = let rec restand e1 = parser [< e2 = reprexp; e = restand (Con (e1, e2)) >] -> e | [< >] -> e1 in match s with parser [< e1 = reprexp; e2 = restand e1 >] -> e2 and reprexp = parser [< 'LSPAR; e = rexp; 'RSPAR >] -> Opt e | [< 'PLUS; e = plusexp >] -> e | [< 'LAPAR; e = rexp; 'RAPAR >] -> OptRep e | [< e = atom >] -> e and plusexp = parser [< 'TERM l; 'LAPAR; e = rexp; 'RAPAR >] -> TermRep (e, Term l) | [< 'LAPAR; e = rexp; 'RAPAR >] -> Rep e and atom = parser [< 'NONTERM l >] -> NonTerm l | [< 'TERM l >] -> Term l | [< 'PARAM l >] -> Param l | [< 'LPAR; e = rexp; 'RPAR >] -> e in rexp (lexer str)