types.mli

   1 (*
   2    A scheme object is anything that can be considered a value in Scheme. Notice that:
   3
   4    - Any symbolic expression can be an object (through the use of quote).
   5    - Some objects have a literal representation in the program (can be read), but others don't: Closures and Continuations are created through evaluation of some other expressions.
   6 *)
   7
   8 type symbol = string ;;
   9
  10 type scheme_object =
  11     Int of int
  12   | String of string
  13   | Symbol of symbol
  14   | Null
  15   | True
  16   | False
  17   | Quotation of scheme_object
  18   | ProperList of scheme_object list
  19   | ImproperList of (scheme_object list) * scheme_object
  20   | Closure of scheme_object * scheme_environment * (symbol list)
  21   | Builtin of ((scheme_object list) -> (scheme_object option))
  22   | Continuation of scheme_environment * (scheme_object list) * (scheme_object list list)
  23   | RestoreEnv of scheme_environment
  24   | Rewind
  25   | Cond of (scheme_object * scheme_object)
  26   | Set of string
  27   | Bind of string
  28 and
  29   environment_frame = (string, scheme_object) Hashtbl.t
  30 and
  31   scheme_environment = environment_frame list
  32 ;;
  33
  34 exception Scheme_cast_error;;
  35 exception Scheme_eval_error of string;;
  36 exception Scheme_user_error of scheme_object list;;