{
  open Parser
  exception Eof
}

let lowercase = ['a'-'z']
let uppercase = ['A'-'Z']
let digit = ['0'-'9'] 
let word = (lowercase | uppercase)*

let var_id = lowercase lowercase* digit*
let ty_id = uppercase uppercase* digit*

rule token = parse
  | [' ' '\t']     { token lexbuf }
  | '\n'            { EOL }
  | '+'             { PLUS }
  | '*'             { TIMES }
  | "True"          { TOP }
  | "False"         { BOT }
  | '('             { LPAREN }
  | ')'             { RPAREN }
  | "fun"           { FUN }
  | ':'             { COLON }
  | "=>"            { ARR }
  | "->"            { TARR }
  | '~'             { TILDE }
  | "exf"           { EXFALSO }
  | var_id as s     { VARID(s) }
  | ty_id as s      { TYID(s) }
  | eof             { raise Eof }