adamc@25: (* Copyright (c) 2008, Adam Chlipala
adamc@25:  * All rights reserved.
adamc@25:  *
adamc@25:  * Redistribution and use in source and binary forms, with or without
adamc@25:  * modification, are permitted provided that the following conditions are met:
adamc@25:  *
adamc@25:  * - Redistributions of source code must retain the above copyright notice,
adamc@25:  *   this list of conditions and the following disclaimer.
adamc@25:  * - Redistributions in binary form must reproduce the above copyright notice,
adamc@25:  *   this list of conditions and the following disclaimer in the documentation
adamc@25:  *   and/or other materials provided with the distribution.
adamc@25:  * - The names of contributors may not be used to endorse or promote products
adamc@25:  *   derived from this software without specific prior written permission.
adamc@25:  *
adamc@25:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
adamc@25:  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
adamc@25:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
adamc@25:  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
adamc@25:  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
adamc@25:  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
adamc@25:  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
adamc@25:  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
adamc@25:  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
adamc@25:  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
adamc@25:  * POSSIBILITY OF SUCH DAMAGE.
adamc@25:  *)
adamc@25: 
adamc@25: structure Monoize :> MONOIZE = struct
adamc@25: 
adamc@25: structure E = ErrorMsg
adamc@25: structure Env = CoreEnv
adamc@25: 
adamc@25: structure L = Core
adamc@25: structure L' = Mono
adamc@25: 
adamc@25: val dummyTyp = (L'.TNamed 0, E.dummySpan)
adamc@25: 
adamc@25: fun monoName env (all as (c, loc)) =
adamc@25:     let
adamc@25:         fun poly () =
adamc@25:             (E.errorAt loc "Unsupported name constructor";
adamc@25:              Print.eprefaces' [("Constructor", CorePrint.p_con env all)];
adamc@25:              "")
adamc@25:     in
adamc@25:         case c of
adamc@25:             L.CName s => s
adamc@25:           | _ => poly ()
adamc@25:     end
adamc@25: 
adamc@25: fun monoType env (all as (c, loc)) =
adamc@25:     let
adamc@25:         fun poly () =
adamc@25:             (E.errorAt loc "Unsupported type constructor";
adamc@25:              Print.eprefaces' [("Constructor", CorePrint.p_con env all)];
adamc@25:              dummyTyp)
adamc@25:     in
adamc@25:         case c of
adamc@25:             L.TFun (c1, c2) => (L'.TFun (monoType env c1, monoType env c2), loc)
adamc@25:           | L.TCFun _ => poly ()
adamc@25:           | L.TRecord (L.CRecord ((L.KType, _), xcs), _) =>
adamc@25:             (L'.TRecord (map (fn (x, t) => (monoName env x, monoType env t)) xcs), loc)
adamc@25:           | L.TRecord _ => poly ()
adamc@25: 
adamc@143:           | L.CApp ((L.CApp ((L.CApp ((L.CFfi ("Basis", "xml"), _), _), _), _), _), _) =>
adamc@143:             (L'.TFfi ("Basis", "string"), loc)
adamc@94: 
adamc@25:           | L.CRel _ => poly ()
adamc@25:           | L.CNamed n => (L'.TNamed n, loc)
adamc@51:           | L.CFfi mx => (L'.TFfi mx, loc)
adamc@25:           | L.CApp _ => poly ()
adamc@25:           | L.CAbs _ => poly ()
adamc@25: 
adamc@25:           | L.CName _ => poly ()
adamc@25: 
adamc@25:           | L.CRecord _ => poly ()
adamc@25:           | L.CConcat _ => poly ()
adamc@69:           | L.CFold _ => poly ()
adamc@87:           | L.CUnit => poly ()
adamc@25:     end
adamc@25: 
adamc@25: val dummyExp = (L'.EPrim (Prim.Int 0), E.dummySpan)
adamc@25: 
adamc@120: fun fooifyExp name env =
adamc@120:     let
adamc@120:         fun fooify (e, tAll as (t, loc)) =
adamc@120:             case #1 e of
adamc@120:                 L'.EClosure (fnam, [(L'.ERecord [], _)]) =>
adamc@120:                 let
adamc@120:                     val (_, _, _, s) = Env.lookupENamed env fnam
adamc@120:                 in
adamc@120:                     (L'.EPrim (Prim.String s), loc)
adamc@120:                 end
adamc@120:               | L'.EClosure (fnam, args) =>
adamc@120:                 let
adamc@120:                     val (_, ft, _, s) = Env.lookupENamed env fnam
adamc@120:                     val ft = monoType env ft
adamc@111: 
adamc@120:                     fun attrify (args, ft, e) =
adamc@120:                         case (args, ft) of
adamc@120:                             ([], _) => e
adamc@120:                           | (arg :: args, (L'.TFun (t, ft), _)) =>
adamc@121:                             attrify (args, ft,
adamc@121:                                      (L'.EStrcat (e,
adamc@121:                                                   (L'.EStrcat ((L'.EPrim (Prim.String "/"), loc),
adamc@121:                                                                fooify (arg, t)), loc)), loc))
adamc@120:                           | _ => (E.errorAt loc "Type mismatch encoding attribute";
adamc@120:                                   e)
adamc@120:                 in
adamc@120:                     attrify (args, ft, (L'.EPrim (Prim.String s), loc))
adamc@120:                 end
adamc@120:               | _ =>
adamc@120:                 case t of
adamc@120:                     L'.TFfi ("Basis", "string") => (L'.EFfiApp ("Basis", name ^ "ifyString", [e]), loc)
adamc@120:                   | L'.TFfi ("Basis", "int") => (L'.EFfiApp ("Basis", name ^ "ifyInt", [e]), loc)
adamc@120:                   | L'.TFfi ("Basis", "float") => (L'.EFfiApp ("Basis", name ^ "ifyFloat", [e]), loc)
adamc@120:                   | L'.TRecord [] => (L'.EPrim (Prim.String ""), loc)
adamc@111: 
adamc@120:                   | _ => (E.errorAt loc "Don't know how to encode attribute type";
adamc@120:                           Print.eprefaces' [("Type", MonoPrint.p_typ MonoEnv.empty tAll)];
adamc@120:                           dummyExp)
adamc@120:     in
adamc@120:         fooify
adamc@120:     end
adamc@120: 
adamc@120: val attrifyExp = fooifyExp "attr"
adamc@120: val urlifyExp = fooifyExp "url"
adamc@105: 
adamc@143: datatype 'a failable_search =
adamc@143:          Found of 'a
adamc@143:        | NotFound
adamc@143:        | Error
adamc@143: 
adamc@153: structure St :> sig
adamc@153:     type t
adamc@153: 
adamc@153:     val empty : t
adamc@153: 
adamc@153:     val radioGroup : t -> string option
adamc@153:     val setRadioGroup : t * string -> t
adamc@153: end = struct
adamc@153: 
adamc@153: type t = {
adamc@153:      radioGroup : string option
adamc@153: }
adamc@153: 
adamc@153: val empty = {radioGroup = NONE}
adamc@153: 
adamc@153: fun radioGroup (t : t) = #radioGroup t
adamc@153: 
adamc@153: fun setRadioGroup (t : t, x) = {radioGroup = SOME x}
adamc@153: 
adamc@153: end
adamc@153: 
adamc@153: fun monoExp (env, st) (all as (e, loc)) =
adamc@25:     let
adamc@25:         fun poly () =
adamc@25:             (E.errorAt loc "Unsupported expression";
adamc@25:              Print.eprefaces' [("Expression", CorePrint.p_exp env all)];
adamc@25:              dummyExp)
adamc@25:     in
adamc@25:         case e of
adamc@25:             L.EPrim p => (L'.EPrim p, loc)
adamc@25:           | L.ERel n => (L'.ERel n, loc)
adamc@25:           | L.ENamed n => (L'.ENamed n, loc)
adamc@51:           | L.EFfi mx => (L'.EFfi mx, loc)
adamc@153:           | L.EFfiApp (m, x, es) => (L'.EFfiApp (m, x, map (monoExp (env, st)) es), loc)
adamc@94: 
adamc@139:           | L.EApp (
adamc@139:             (L.ECApp (
adamc@141:              (L.ECApp ((L.EFfi ("Basis", "cdata"), _), _), _),
adamc@139:              _), _),
adamc@153:             se) => (L'.EFfiApp ("Basis", "htmlifyString", [monoExp (env, st) se]), loc)
adamc@95:           | L.EApp (
adamc@95:             (L.EApp (
adamc@95:              (L.ECApp (
adamc@95:               (L.ECApp (
adamc@95:                (L.ECApp (
adamc@139:                 (L.ECApp (
adamc@140:                  (L.EFfi ("Basis", "join"),
adamc@139:                      _), _), _),
adamc@139:                 _), _),
adamc@95:                _), _),
adamc@95:               _), _),
adamc@95:              xml1), _),
adamc@153:             xml2) => (L'.EStrcat (monoExp (env, st) xml1, monoExp (env, st) xml2), loc)
adamc@95: 
adamc@95:           | L.EApp (
adamc@95:             (L.EApp (
adamc@104:              (L.EApp (
adamc@95:               (L.ECApp (
adamc@104:                (L.ECApp (
adamc@104:                 (L.ECApp (
adamc@104:                  (L.ECApp (
adamc@139:                   (L.ECApp (
adamc@139:                    (L.ECApp (
adamc@139:                     (L.ECApp (
adamc@139:                      (L.ECApp (
adamc@139:                       (L.EFfi ("Basis", "tag"),
adamc@139:                        _), _), _), _), _), _), _), _), _), _), _), _), _), _), _), _), _),
adamc@104:               attrs), _),
adamc@95:              tag), _),
adamc@95:             xml) =>
adamc@95:             let
adamc@140:                 fun getTag' (e, _) =
adamc@140:                     case e of
adamc@143:                         L.EFfi ("Basis", tag) => (tag, [])
adamc@143:                       | L.ECApp (e, t) => let
adamc@143:                             val (tag, ts) = getTag' e
adamc@143:                         in
adamc@143:                             (tag, ts @ [t])
adamc@143:                         end
adamc@140:                       | _ => (E.errorAt loc "Non-constant XML tag";
adamc@140:                               Print.eprefaces' [("Expression", CorePrint.p_exp env tag)];
adamc@143:                               ("", []))
adamc@140: 
adamc@95:                 fun getTag (e, _) =
adamc@95:                     case e of
adamc@143:                         L.EFfiApp ("Basis", tag, [(L.ERecord [], _)]) => (tag, [])
adamc@140:                       | L.EApp (e, (L.ERecord [], _)) => getTag' e
adamc@95:                       | _ => (E.errorAt loc "Non-constant XML tag";
adamc@95:                               Print.eprefaces' [("Expression", CorePrint.p_exp env tag)];
adamc@143:                               ("", []))
adamc@95: 
adamc@143:                 val (tag, targs) = getTag tag
adamc@95: 
adamc@153:                 val attrs = monoExp (env, st) attrs
adamc@104: 
adamc@143:                 fun tagStart tag =
adamc@104:                     case #1 attrs of
adamc@104:                         L'.ERecord xes =>
adamc@104:                         let
adamc@104:                             fun lowercaseFirst "" = ""
adamc@143:                               | lowercaseFirst s = str (Char.toLower (String.sub (s, 0)))
adamc@143:                                                    ^ String.extract (s, 1, NONE)
adamc@104: 
adamc@104:                             val s = (L'.EPrim (Prim.String (String.concat ["<", tag])), loc)
adamc@104:                         in
adamc@105:                             foldl (fn ((x, e, t), s) =>
adamc@104:                                       let
adamc@104:                                           val xp = " " ^ lowercaseFirst x ^ "=\""
adamc@120: 
adamc@120:                                           val fooify =
adamc@120:                                               case x of
adamc@120:                                                   "Link" => urlifyExp
adamc@143:                                                 | "Action" => urlifyExp
adamc@120:                                                 | _ => attrifyExp
adamc@104:                                       in
adamc@104:                                           (L'.EStrcat (s,
adamc@104:                                                        (L'.EStrcat ((L'.EPrim (Prim.String xp), loc),
adamc@120:                                                                     (L'.EStrcat (fooify env (e, t),
adamc@143:                                                                                  (L'.EPrim (Prim.String "\""),
adamc@143:                                                                                   loc)),
adamc@104:                                                                      loc)),
adamc@104:                                                         loc)), loc)
adamc@104:                                       end)
adamc@143:                                   s xes
adamc@104:                         end
adamc@143:                       | _ => raise Fail "Non-record attributes!"
adamc@104: 
adamc@143:                 fun input typ =
adamc@143:                     case targs of
adamc@143:                         [(L.CName name, _)] =>
adamc@143:                         (L'.EStrcat (tagStart "input",
adamc@143:                                      (L'.EPrim (Prim.String (" type=\"" ^ typ ^ "\" name=\"" ^ name ^ "\"/>")),
adamc@143:                                       loc)), loc)
adamc@143:                       | _ => (Print.prefaces "Targs" (map (fn t => ("T", CorePrint.p_con env t)) targs);
adamc@153:                               raise Fail "No name passed to input tag")
adamc@104: 
adamc@152:                 fun normal (tag, extra) =
adamc@143:                     let
adamc@143:                         val tagStart = tagStart tag
adamc@152:                         val tagStart = case extra of
adamc@152:                                            NONE => tagStart
adamc@152:                                          | SOME extra => (L'.EStrcat (tagStart, extra), loc)
adamc@152: 
adamc@143:                         fun normal () =
adamc@143:                             (L'.EStrcat ((L'.EStrcat (tagStart, (L'.EPrim (Prim.String ">"), loc)), loc),
adamc@153:                                          (L'.EStrcat (monoExp (env, st) xml,
adamc@143:                                                       (L'.EPrim (Prim.String (String.concat ["</", tag, ">"])),
adamc@143:                                                        loc)), loc)),
adamc@143:                              loc)
adamc@143:                     in
adamc@143:                         case xml of
adamc@143:                             (L.EApp ((L.ECApp (
adamc@143:                                       (L.ECApp ((L.EFfi ("Basis", "cdata"), _),
adamc@143:                                                 _), _),
adamc@143:                                       _), _),
adamc@143:                                      (L.EPrim (Prim.String s), _)), _) =>
adamc@143:                             if CharVector.all Char.isSpace s then
adamc@143:                                 (L'.EStrcat (tagStart, (L'.EPrim (Prim.String "/>"), loc)), loc)
adamc@143:                             else
adamc@143:                                 normal ()
adamc@143:                           | _ => normal ()
adamc@143:                     end
adamc@152:             in
adamc@152:                 case tag of
adamc@152:                     "submit" => (L'.EPrim (Prim.String "<input type=\"submit\"/>"), loc)
adamc@152: 
adamc@152:                   | "textbox" =>
adamc@152:                     (case targs of
adamc@152:                          [_, (L.CName name, _)] =>
adamc@152:                          (L'.EStrcat (tagStart "input",
adamc@152:                                       (L'.EPrim (Prim.String (" name=\"" ^ name ^ "\"/>")),
adamc@152:                                        loc)), loc)
adamc@152:                        | _ => (Print.prefaces "Targs" (map (fn t => ("T", CorePrint.p_con env t)) targs);
adamc@153:                                raise Fail "No name passed to textarea tag"))
adamc@152:                   | "ltextarea" =>
adamc@152:                     (case targs of
adamc@152:                          [_, (L.CName name, _)] =>
adamc@152:                          (L'.EStrcat ((L'.EStrcat (tagStart "textarea",
adamc@152:                                                    (L'.EPrim (Prim.String (" name=\"" ^ name ^ "\">")), loc)), loc),
adamc@153:                                       (L'.EStrcat (monoExp (env, st) xml,
adamc@152:                                                    (L'.EPrim (Prim.String "</textarea>"),
adamc@152:                                                     loc)), loc)),
adamc@152:                           loc)
adamc@152:                        | _ => (Print.prefaces "Targs" (map (fn t => ("T", CorePrint.p_con env t)) targs);
adamc@153:                                raise Fail "No name passed to ltextarea tag"))
adamc@153: 
adamc@153:                   | "radio" =>
adamc@153:                     (case targs of
adamc@153:                          [_, (L.CName name, _)] =>
adamc@153:                          monoExp (env, St.setRadioGroup (st, name)) xml
adamc@153:                        | _ => (Print.prefaces "Targs" (map (fn t => ("T", CorePrint.p_con env t)) targs);
adamc@153:                                raise Fail "No name passed to radio tag"))
adamc@153:                   | "radioOption" =>
adamc@153:                     (case St.radioGroup st of
adamc@153:                          NONE => raise Fail "No name for radioGroup"
adamc@153:                        | SOME name =>
adamc@153:                          normal ("input",
adamc@153:                                  SOME (L'.EPrim (Prim.String (" type=\"radio\" name=\"" ^ name ^ "\"")), loc)))
adamc@152: 
adamc@152:                   | _ => normal (tag, NONE)
adamc@95:             end
adamc@94: 
adamc@141:           | L.EApp ((L.ECApp (
adamc@141:                      (L.ECApp ((L.EFfi ("Basis", "lform"), _), _), _),
adamc@141:                      _), _),
adamc@141:                     xml) =>
adamc@143:             let
adamc@143:                 fun findSubmit (e, _) =
adamc@143:                     case e of
adamc@143:                         L.EApp (
adamc@143:                         (L.EApp (
adamc@143:                          (L.ECApp (
adamc@143:                           (L.ECApp (
adamc@143:                            (L.ECApp (
adamc@143:                             (L.ECApp (
adamc@143:                              (L.EFfi ("Basis", "join"),
adamc@143:                               _), _), _),
adamc@143:                             _), _),
adamc@143:                            _), _),
adamc@143:                           _), _),
adamc@143:                          xml1), _),
adamc@143:                         xml2) => (case findSubmit xml1 of
adamc@143:                                       Error => Error
adamc@143:                                     | NotFound => findSubmit xml2
adamc@143:                                     | Found e =>
adamc@143:                                       case findSubmit xml2 of
adamc@143:                                           NotFound => Found e
adamc@143:                                         | _ => Error)
adamc@143:                       | L.EApp (
adamc@143:                         (L.EApp (
adamc@143:                          (L.EApp (
adamc@143:                           (L.ECApp (
adamc@143:                            (L.ECApp (
adamc@143:                             (L.ECApp (
adamc@143:                              (L.ECApp (
adamc@143:                               (L.ECApp (
adamc@143:                                (L.ECApp (
adamc@143:                                 (L.ECApp (
adamc@143:                                  (L.ECApp (
adamc@143:                                   (L.EFfi ("Basis", "tag"),
adamc@143:                                    _), _), _), _), _), _), _), _), _), _), _), _), _), _), _), _), _),
adamc@143:                           attrs), _),
adamc@143:                          _), _),
adamc@143:                         xml) =>
adamc@143:                         (case #1 attrs of
adamc@143:                              L.ERecord xes =>
adamc@143:                              (case ListUtil.search (fn ((L.CName "Action", _), e, t) => SOME (e, t)
adamc@143:                                                      | _ => NONE) xes of
adamc@143:                                   NONE => findSubmit xml
adamc@143:                                 | SOME et =>
adamc@143:                                   case findSubmit xml of
adamc@143:                                       NotFound => Found et
adamc@143:                                     | _ => Error)
adamc@143:                            | _ => findSubmit xml)
adamc@143:                       | _ => NotFound
adamc@143: 
adamc@143:                 val (action, actionT) = case findSubmit xml of
adamc@143:                     NotFound => raise Fail "No submit found"
adamc@143:                   | Error => raise Fail "Not ready for multi-submit lforms yet"
adamc@143:                   | Found et => et
adamc@143: 
adamc@143:                 val actionT = monoType env actionT
adamc@153:                 val action = monoExp (env, st) action
adamc@143:             in
adamc@143:                 (L'.EStrcat ((L'.EStrcat ((L'.EPrim (Prim.String "<form action=\""), loc),
adamc@143:                                           (L'.EStrcat (urlifyExp env (action, actionT),
adamc@143:                                                        (L'.EPrim (Prim.String "\">"), loc)), loc)), loc),
adamc@153:                              (L'.EStrcat (monoExp (env, st) xml,
adamc@143:                                           (L'.EPrim (Prim.String "</form>"), loc)), loc)), loc)
adamc@143:             end
adamc@141: 
adamc@148:           | L.EApp ((L.ECApp (
adamc@148:                      (L.ECApp (
adamc@148:                       (L.ECApp (
adamc@148:                        (L.ECApp (
adamc@148:                         (L.EFfi ("Basis", "useMore"), _), _), _),
adamc@148:                        _), _),
adamc@148:                       _), _),
adamc@148:                      _), _),
adamc@153:                     xml) => monoExp (env, st) xml
adamc@148:                      
adamc@148: 
adamc@153:           | L.EApp (e1, e2) => (L'.EApp (monoExp (env, st) e1, monoExp (env, st) e2), loc)
adamc@26:           | L.EAbs (x, dom, ran, e) =>
adamc@153:             (L'.EAbs (x, monoType env dom, monoType env ran, monoExp (Env.pushERel env x dom, st) e), loc)
adamc@25:           | L.ECApp _ => poly ()
adamc@25:           | L.ECAbs _ => poly ()
adamc@25: 
adamc@153:           | L.ERecord xes => (L'.ERecord (map (fn (x, e, t) => (monoName env x,
adamc@153:                                                                 monoExp (env, st) e,
adamc@153:                                                                 monoType env t)) xes), loc)
adamc@153:           | L.EField (e, x, _) => (L'.EField (monoExp (env, st) e, monoName env x), loc)
adamc@149:           | L.ECut _ => poly ()
adamc@73:           | L.EFold _ => poly ()
adamc@153:           | L.EWrite e => (L'.EWrite (monoExp (env, st) e), loc)
adamc@110: 
adamc@153:           | L.EClosure (n, es) => (L'.EClosure (n, map (monoExp (env, st)) es), loc)
adamc@25:     end
adamc@25: 
adamc@25: fun monoDecl env (all as (d, loc)) =
adamc@25:     let
adamc@25:         fun poly () =
adamc@25:             (E.errorAt loc "Unsupported declaration";
adamc@25:              Print.eprefaces' [("Declaration", CorePrint.p_decl env all)];
adamc@25:              NONE)
adamc@25:     in
adamc@25:         case d of
adamc@25:             L.DCon _ => NONE
adamc@109:           | L.DVal (x, n, t, e, s) => SOME (Env.pushENamed env x n t (SOME e) s,
adamc@153:                                             (L'.DVal (x, n, monoType env t, monoExp (env, St.empty) e, s), loc))
adamc@128:           | L.DValRec vis =>
adamc@128:             let
adamc@128:                 val env = foldl (fn ((x, n, t, e, s), env) => Env.pushENamed env x n t NONE s) env vis
adamc@128:             in
adamc@128:                 SOME (env,
adamc@153:                       (L'.DValRec (map (fn (x, n, t, e, s) => (x, n, monoType env t,
adamc@153:                                                                monoExp (env, St.empty) e, s)) vis), loc))
adamc@128:             end
adamc@144:           | L.DExport (ek, n) =>
adamc@115:             let
adamc@120:                 val (_, t, _, s) = Env.lookupENamed env n
adamc@120: 
adamc@120:                 fun unwind (t, _) =
adamc@120:                     case t of
adamc@120:                         L.TFun (dom, ran) => dom :: unwind ran
adamc@120:                       | _ => []
adamc@120: 
adamc@120:                 val ts = map (monoType env) (unwind t)
adamc@115:             in
adamc@144:                 SOME (env, (L'.DExport (ek, s, n, ts), loc))
adamc@115:             end
adamc@25:     end
adamc@25: 
adamc@25: fun monoize env ds =
adamc@25:     let
adamc@25:         val (_, ds) = List.foldl (fn (d, (env, ds)) =>
adamc@25:                                      case monoDecl env d of
adamc@25:                                          NONE => (env, ds)
adamc@25:                                        | SOME (env, d) => (env, d :: ds)) (env, []) ds
adamc@25:     in
adamc@25:         rev ds
adamc@25:     end
adamc@25: 
adamc@25: end