actionmap.sml

(* $Id$
 *
 * Copyright (c) 2008 Timothy Bourke (University of NSW and NICTA)
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the "BSD License" which is distributed with the
 * software in the file LICENSE.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the BSD
 * License for more details.
 *)

structure ActionMap : sig
  include ORD_MAP

  val actionInsert : ((Atom.atom * 'a) * 'a map) -> 'a map
end
=
let structure E = Expression
in struct
  open ActionRedBlackMap

  fun actionInsert ((chandir, v), m) = let
      fun getTail (l, r) = (Atom.atom (Substring.string l), Substring.first r)

      val s = Substring.full (Atom.toString chandir)
      val l = Substring.size s
      val (n, d) = if l = 0 then (chandir, NONE)
                   else getTail (Substring.splitAt (s, l-1))
    in
      case d of
        SOME #"?" => insert' (((n, E.Input),  v), m)
      | SOME #"!" => insert' (((n, E.Output), v), m)
      | _ => let val m' = insert' (((n, E.Input), v), m)
             in insert' (((n, E.Output), v), m') end
    end

end end