--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/name_js.sml	Thu Aug 02 18:12:37 2012 -0400
@@ -0,0 +1,151 @@
+(* Copyright (c) 2012, Adam Chlipala
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ * - The names of contributors may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *)
+
+(* Phase that introduces names for fragments of JavaScript code, so that they
+ * may be moved to app.js and not repeated in each generated page *)
+
+structure NameJS :> NAME_JS = struct
+
+open Mono
+
+structure U = MonoUtil
+structure IS = IntBinarySet
+
+val freeVars = U.Exp.foldB {typ = #2,
+                            exp = fn (free, e, vs) =>
+                                     case e of
+                                         ERel n =>
+                                         if n < free then
+                                             vs
+                                         else
+                                             IS.add (vs, n - free)
+                                       | _ => vs,
+                            bind = fn (free, b) =>
+                                      case b of
+                                          U.Exp.RelE _ => free+1
+                                        | _ => free}
+               0 IS.empty
+
+fun index (ls, v) =
+    case ls of
+        [] => raise Fail "NameJs.index"
+      | v' :: ls' => if v = v' then 0 else 1 + index (ls', v)
+
+fun squish vs = U.Exp.mapB {typ = fn x => x,
+                            exp = fn free => fn e =>
+                                                case e of
+                                                    ERel n =>
+                                                    if n < free then
+                                                        e
+                                                    else
+                                                        ERel (free + index (vs, n - free) + 1)
+                                                  | _ => e,
+                            bind = fn (free, b) =>
+                                      case b of
+                                          U.Exp.RelE _ => free+1
+                                        | _ => free}
+                           0
+
+fun rewrite file =
+    let
+        val (file, _) = ListUtil.foldlMapConcat (fn (d, nextName) =>
+                                                    let
+                                                        val (d, (nextName, newDs)) =
+                                                            U.Decl.foldMapB {typ = fn x => x,
+                                                                             decl = fn (_, e, s) => (e, s),
+                                                                             exp = fn (env, e, st as (nextName, newDs)) =>
+                                                                                      case e of
+                                                                                          EJavaScript (mode, e') =>
+                                                                                          (case mode of
+                                                                                               Source _ => (e, st)
+                                                                                             | _ =>
+                                                                                               let
+                                                                                                   fun isTrulySimple (e, _) =
+                                                                                                       case e of
+                                                                                                           ERel _ => true
+                                                                                                         | ENamed _ => true
+                                                                                                         | ERecord [] => true
+                                                                                                         | _ => false
+
+                                                                                                   fun isAlreadySimple e =
+                                                                                                       case #1 e of
+                                                                                                           EApp (e, arg) => isTrulySimple arg andalso isAlreadySimple e
+                                                                                                         | _ => isTrulySimple e
+                                                                                               in
+                                                                                                   if isAlreadySimple e' then
+                                                                                                       (e, st)
+                                                                                                   else
+                                                                                                       let
+                                                                                                           val loc = #2 e'
+
+                                                                                                           val vs = freeVars e'
+                                                                                                           val vs = IS.listItems vs
+                                                                                                                    
+                                                                                                           val x = "script" ^ Int.toString nextName
+                                                                                                                   
+                                                                                                           val un = (TRecord [], loc)
+                                                                                                           val s = (TFfi ("Basis", "string"), loc)
+                                                                                                           val base = (TFun (un, s), loc)
+                                                                                                           val t = foldl (fn (n, t) => (TFun (#2 (List.nth (env, n)), t), loc)) base vs
+                                                                                                           val e' = squish vs e'
+                                                                                                           val e' = (EAbs ("_", un, s, e'), loc)
+                                                                                                           val (e', _) = foldl (fn (n, (e', t)) =>
+                                                                                                                                   let
+                                                                                                                                       val (x, this) = List.nth (env, n)
+                                                                                                                                   in
+                                                                                                                                       ((EAbs (x, this, t, e'), loc),
+                                                                                                                                        (TFun (this, t), loc))
+                                                                                                                                   end) (e', base) vs
+                                                                                                           val d = (x, nextName, t, e', "<script>")
+
+                                                                                                           val e = (ENamed nextName, loc)
+                                                                                                           val e = foldr (fn (n, e) => (EApp (e, (ERel n, loc)), loc)) e vs
+                                                                                                           val e = (EApp (e, (ERecord [], loc)), loc)
+                                                                                                           val e = EJavaScript (Script, e)
+                                                                                                       in
+                                                                                                           (e, (nextName+1, d :: newDs))
+                                                                                                       end
+                                                                                               end)
+                                                                                        | _ => (e, st),
+                                                                             bind = fn (env, b) =>
+                                                                                       case b of
+                                                                                           U.Decl.RelE x => x :: env
+                                                                                         | _ => env}
+                                                            [] (nextName, []) d
+                                                    in
+                                                        (case newDs of
+                                                             [] => [d]
+                                                           | _ => case #1 d of
+                                                                      DValRec vis => [(DValRec (vis @ newDs), #2 d)]
+                                                                    | _ => List.revAppend (map (fn vi => (DVal vi, #2 d)) newDs, [d]),
+                                                         nextName)
+                                                    end) (U.File.maxName file + 1) file
+    in
+        file
+    end
+
+end