Better error message for fwtool

[hcoop/domtool2.git] / src / defaults.sml

(* HCoop Domtool (http://hcoop.sourceforge.net/)
 * Copyright (c) 2006, Adam Chlipala
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * 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
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *)

(* Default record field database *)

structure Defaults :> DEFAULTS = struct

open Ast Print

structure SM = StringMap

val dmy = ErrorMsg.dummyLoc

val defaultT : record ref = ref SM.empty
val defaultV : (unit -> exp) SM.map ref = ref SM.empty

fun registerDefault (name, t, v) =
    case SM.find (!defaultT, name) of
	NONE => (defaultT := SM.insert (!defaultT, name, t);
		 defaultV := SM.insert (!defaultV, name, v))
      | SOME _ => raise Fail "Duplicate default environment variable"

fun allSets (e, _) =
    case e of
	ESkip => true
      | ESet _ => true
      | ESeq es => List.all allSets es
      | _ => false

val dmy = ErrorMsg.dummyLoc

fun bodyType (_, _, SOME e) =
    if allSets e then
	(CPrefix (CRoot, dmy), dmy)
    else
	(CRoot, dmy)
  | bodyType _ = (CRoot, dmy)

fun tInit p =
    (TAction (bodyType p,
	      !defaultT,
	      StringMap.empty),
     dmy)

fun eInit () = SM.map (fn f => f ()) (!defaultV)


end