open Tfbsrxast;;
open Tfbsrxpp;;

exception TypeError

(*
 * If you would like typechecking to be enabled by your interpreter by default,
 * then change the following value to true.  Whether or not typechecking is
 * enabled by default, you can explicitly enable it or disable it using
 * command-line arguments.
 *)
let typecheck_default_enabled = true;;

(*
 * Replace this with your typechecker code.  Your code should not throw the
 * following exception; if you need to raise an exception, create your own
 * exception type here.
 *)

let rec typecheck_aux gamma e = match e with
    | Var(ident) -> TInt
    | Function(ident, fbtype, expr) -> TInt
    | Letrec(ident, ident2, fbtype, expr1, fbtype2, expr2) -> TInt
    | Appl(expr1, expr2) -> TInt
    | Plus(expr1, expr2) ->
        if (typecheck_aux gamma expr1 = TInt && typecheck_aux gamma expr2 = TInt)
        then TInt else raise TypeError
    | Minus(expr1, expr2) ->
        if (typecheck_aux gamma expr1 = TInt && typecheck_aux gamma expr2 = TInt)
        then TInt else raise TypeError
    | Equal(expr1, expr2) ->
        if (typecheck_aux gamma expr1 = TInt && typecheck_aux gamma expr2 = TInt)
        then TInt else raise TypeError
    | And(expr1, expr2) -> TInt
    | Or(expr1, expr2) -> TInt
    | Not(expr1) -> TInt
    | If(expr1, expr2, expr3) -> TInt
    | Int(int) -> TInt
    | Bool(bool) -> TBool
    | Ref(expr) -> TInt
    | Set(expr1, expr2) -> TInt
    | Get(expr) -> TInt
    | Record(recordlist) -> TInt
    | Select(label, expr) -> TInt
    | Raise(exnid, fbtype, expr) -> TInt
    | Try(expr1, exnid, ident, fbtype, expr2) -> TInt
    | Cell(int) -> TInt
;;

let typecheck e = typecheck_aux [] e;;