{
open Be_parser
}

let address   = ['0'-'9']+

(* let ADD       = "add"
let SUB       = "sub"
let NEG       = "neg"
let EQ        = "eq"
let GT        = "gt"
let LT        = "lt"
let AND       = "and"
let OR        = "or"
let NOT       = "not"
let POP       = "pop"
let PUSH      = "push" *)

let command   = "add"
              | "sub"
              | "neg"
              | "eq"
              | "gt"
              | "lt"
              | "and"
              | "or"
              | "not"
              | "pop"
              | "push"

let segment   = "argument"
              | "local"
              | "static"
              | "this"
              | "that"
              | "pointer"
              | "temp"
              | "constant"

let white     = [' ' '\t']+
let comment   = "//" _*

(* 
let digit      = ['0'-'9']
let letter     = ['a'-'z' 'A'-'Z']
let special    = ['.' '$' '_' '-' '+' '&' '!' '|']
let id         = (digit | letter | special)+ 
*)

rule read =
  parse
  | white          { read lexbuf }
  | address as a   { ADDRESS (a) }
  | command as c   { COMMAND (c) }
  | segment as s   { SEGMENT (s) }
  | comment as c   { COMMENT (c) }
  | eof            { EOF }