// Example of how to extend parserm.fs

open System;
open Microsoft.FSharp.Math;;
open System.Collections.Generic;;
open CSC7B;;    // compile with -r parserm.dll

// add the power operator
newoperator "\^" 700;; // need escape char \ for some chars (not %)
binops <- List.append binops ["^"];;

let eval0 = eval;
eval <- fun env exp ->
  match exp with
    | Binop("^",a,b) ->
       let ea,eb = (eval env a), (eval env b)
       int(Math.Pow(float(ea),float(eb)))
    | e -> eval0 env e;;


advice_io(true,run);; // run with just console prompt and input advice