Lex.fsl

{

module Lex

open Microsoft.FSharp.Text.Lexing
open Par;

let lexemeAsString lexbuf =
    LexBuffer<char>.LexemeString lexbuf

}

let char      = ['a'-'z' 'A'-'Z']
let aps       = '\''
let eps       = "eps"
let star      = '*'
let alt       = '|'
let lpar      = '('
let rpar      = ')'
let whitespace = [' ' '\t' '\r' '\n']

rule Token = parse
  | char             { Token lexbuf }
  | aps              { APS }
  | eps              { EPS }
  | star             { STAR }
  | alt              { ALT }
  | lpar             { LPAR }
  | rpar             { RPAR }
  | whitespace       { Token lexbuf }
  | eof              { EOF }
  | _                { failwith "Lexer error: illegal symbol" }