lib/mlton/basic/property-list.sig

   1 (* Copyright (C) 2009 Matthew Fluet.
   2  * Copyright (C) 1999-2005 Henry Cejtin, Matthew Fluet, Suresh
   3  *    Jagannathan, and Stephen Weeks.
   4  *
   5  * MLton is released under a BSD-style license.
   6  * See the file MLton-LICENSE for details.
   7  *)
   8
   9 signature PROPERTY_LIST =
  10    sig
  11       type t
  12
  13       (* remove all properties from the list *)
  14       val clear: t -> unit
  15       (* pointer equality of property lists *)
  16       val equals: t * t -> bool
  17       val length: t -> int
  18       (* create an empty property list *)
  19       val new: unit -> t
  20       (* create a new property *)
  21       val newProperty:
  22          unit -> {
  23                   (* See if a property is in a property list.
  24                    * NONE if it isn't.
  25                    *)
  26                   peek: t -> 'a option,
  27                   (* Add the value of the property -- must not already exist. *)
  28                   add: t * 'a -> unit,
  29                   (* Remove a property from a property list.
  30                    * Noop if the property isn't there.
  31                    *)
  32                   remove: t -> unit
  33                   }
  34       val stats: unit -> Layout.t
  35    end