(* operators-sig.sml
 *
 * COPYRIGHT (c) 2010 The Diderot Project (http://diderot.cs.uchicago.edu)
 * All rights reserved.
 *
 * Abstract interface used to parameterize the intermediate representation
 * over the allowed operators.
 *)

signature OPERATORS =
  sig

    type rator

    val arity : rator -> int			(* operator arity *)
    val same : rator * rator -> rator		(* equality test *)
    val hash : rator -> word			(* hash key *)

    val toString : rator -> string

  end