compiler/src/lib/tiger/tiger_symbol.ml

   1 module H = MoreLabels.Hashtbl
   2
   3 type t =
   4   { name   : string
   5   ; symbol : int
   6   }
   7
   8 let next =
   9   let counter = ref 0 in
  10   fun () ->
  11     incr counter;
  12     !counter
  13
  14 let symbols = H.create 16
  15
  16 let unique_of_string name =
  17   {name; symbol = next ()}
  18
  19 let of_string name =
  20   match H.find_opt symbols name with
  21   | Some symbol ->
  22       {name; symbol}
  23   | None ->
  24       let t = unique_of_string name in
  25       H.replace symbols ~key:t.name ~data:t.symbol;
  26       t
  27
  28 let to_string {name; _} =
  29   name
  30
  31 let is_equal {symbol=s1; _} {symbol=s2; _} =
  32   s1 = s2
  33
  34 let show {name; symbol} =
  35   Printf.sprintf "Symbol[%S, %d]" name symbol