summaryrefslogtreecommitdiff
path: root/src/unnest.sml
blob: b56daf8a2ae713fa38f958ee32146f3579c7e077 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
(* Copyright (c) 2008, 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.
 *)

(* Remove nested function definitions *)

structure Unnest :> UNNEST = struct

open Elab

structure E = ElabEnv
structure U = ElabUtil

structure IS = IntBinarySet

val fvsCon = U.Con.foldB {kind = fn (_, st) => st,
                          con = fn (cb, c, cvs) =>
                                   case c of
                                       CRel n =>
                                       if n >= cb then
                                           IS.add (cvs, n - cb)
                                       else
                                           cvs
                                     | _ => cvs,
                          bind = fn (cb, b) =>
                                    case b of
                                        U.Con.Rel _ => cb + 1
                                      | _ => cb}
                         0 IS.empty

fun fvsExp nr = U.Exp.foldB {kind = fn (_, st) => st,
                             con = fn ((cb, eb), c, st as (cvs, evs)) =>
                                      case c of
                                          CRel n =>
                                          if n >= cb then
                                              (IS.add (cvs, n - cb), evs)
                                          else
                                              st
                                        | _ => st,
                             exp = fn ((cb, eb), e, st as (cvs, evs)) =>
                                      case e of
                                          ERel n =>
                                          if n >= eb then
                                              (cvs, IS.add (evs, n - eb))
                                          else
                                              st
                                        | _ => st,
                             bind = fn (ctx as (cb, eb), b) =>
                                       case b of
                                           U.Exp.RelC _ => (cb + 1, eb)
                                         | U.Exp.RelE _ => (cb, eb + 1)
                                         | _ => ctx}
                            (0, nr) (IS.empty, IS.empty)

fun positionOf (x : int) ls =
    let
        fun po n ls =
            case ls of
                [] => raise Fail "Unnest.positionOf"
              | x' :: ls' =>
                if x' = x then
                    n
                else
                    po (n + 1) ls'
    in
        po 0 ls
        handle Fail _ => raise Fail ("Unnset.positionOf("
                                     ^ Int.toString x
                                     ^ ", "
                                     ^ String.concatWith ";" (map Int.toString ls)
                                     ^ ")")
    end

fun squishCon cfv =
    U.Con.mapB {kind = fn k => k,
                con = fn cb => fn c =>
                                  case c of
                                      CRel n =>
                                      if n >= cb then
                                          CRel (positionOf (n - cb) cfv + cb)
                                      else
                                          c
                                    | _ => c,
                bind = fn (cb, b) =>
                          case b of
                              U.Con.Rel _ => cb + 1
                            | _ => cb}
               0

fun squishExp (nr, cfv, efv) =
    U.Exp.mapB {kind = fn k => k,
                con = fn (cb, eb) => fn c =>
                                        case c of
                                            CRel n =>
                                            if n >= cb then
                                                CRel (positionOf (n - cb) cfv + cb)
                                            else
                                                c
                                          | _ => c,
                exp = fn (cb, eb) => fn e =>
                                        case e of
                                            ERel n =>
                                            if n >= eb then
                                                ERel (positionOf (n - eb) efv + eb)
                                            else
                                                e
                                          | _ => e,
                bind = fn (ctx as (cb, eb), b) =>
                          case b of
                              U.Exp.RelC _ => (cb + 1, eb)
                            | U.Exp.RelE _ => (cb, eb + 1)
                            | _ => ctx}
               (0, nr)

type state = {
     maxName : int,
     decls : (string * int * con * exp) list
}

fun kind (k, st) = (k, st)

fun exp ((ks, ts), e as old, st : state) =
    case e of
        ELet (eds, e) =>
        let
            (*val () = Print.prefaces "let" [("e", ElabPrint.p_exp E.empty (old, ErrorMsg.dummySpan))]*)

            val doSubst = foldl (fn (p, e) => E.subExpInExp p e)

            val (eds, (ts, maxName, ds, subs)) =
                ListUtil.foldlMapConcat
                (fn (ed, (ts, maxName, ds, subs)) =>
                    case #1 ed of
                        EDVal (x, t, _) => ([ed],
                                            ((x, t) :: ts,
                                             maxName, ds, map (fn (n, e) => (n + 1, E.liftExpInExp 0 e)) subs))
                      | EDValRec vis =>
                        let
                            val loc = #2 ed

                            val nr = length vis
                            val (cfv, efv) = foldl (fn ((_, t, e), (cfv, efv)) =>
                                                       let
                                                           val (cfv', efv') = fvsExp nr e
                                                           (*val () = Print.prefaces "fvsExp"
                                                                    [("e", ElabPrint.p_exp E.empty e),
                                                                     ("cfv", Print.PD.string
                                                                                 (Int.toString (IS.numItems cfv'))),
                                                                     ("efv", Print.PD.string
                                                                                 (Int.toString (IS.numItems efv')))]*)
                                                           val cfv'' = fvsCon t
                                                       in
                                                           (IS.union (cfv, IS.union (cfv', cfv'')),
                                                            IS.union (efv, efv'))
                                                       end)
                                                   (IS.empty, IS.empty) vis

                            (*val () = print ("A: " ^ Int.toString (length ts) ^ ", " ^ Int.toString (length ks) ^ "\n")
                            val () = app (fn (x, t) =>
                                             Print.prefaces "Var" [("x", Print.PD.string x),
                                                                   ("t", ElabPrint.p_con E.empty t)]) ts*)
                            val cfv = IS.foldl (fn (x, cfv) =>
                                                   let
                                                       (*val () = print (Int.toString x ^ "\n")*)
                                                       val (_, t) = List.nth (ts, x)
                                                   in
                                                       IS.union (cfv, fvsCon t)
                                                   end)
                                               cfv efv
                            (*val () = print "B\n"*)

                            val (vis, maxName) =
                                ListUtil.foldlMap (fn ((x, t, e), maxName) =>
                                                      ((x, maxName, t, e),
                                                       maxName + 1))
                                maxName vis

                            fun apply e =
                                let
                                    val e = IS.foldr (fn (x, e) =>
                                                         (ECApp (e, (CRel x, loc)), loc))
                                            e cfv
                                in
                                    IS.foldr (fn (x, e) =>
                                                 (EApp (e, (ERel x, loc)), loc))
                                             e efv
                                end

                            val subs = map (fn (n, e) => (n + nr, E.liftExpInExp nr e)) subs

                            val subs' = ListUtil.mapi (fn (i, (_, n, _, _)) =>
                                                          let
                                                              val dummy = (EError, ErrorMsg.dummySpan)
                                                                          
                                                              fun repeatLift k =
                                                                  if k = 0 then
                                                                      apply (ENamed n, loc)
                                                                  else
                                                                      E.liftExpInExp 0 (repeatLift (k - 1))
                                                          in
                                                              (0, repeatLift i)
                                                          end)
                                                      vis

                            val subs' = rev subs'

                            val cfv = IS.listItems cfv
                            val efv = IS.listItems efv
                            val efn = length efv

                            val subs = subs @ subs'

                            val vis = map (fn (x, n, t, e) =>
                                              let
                                                  (*val () = Print.prefaces "preSubst"
                                                                          [("e", ElabPrint.p_exp E.empty e)]*)
                                                  val e = doSubst e subs

                                                  (*val () = Print.prefaces "squishCon"
                                                                          [("t", ElabPrint.p_con E.empty t)]*)
                                                  val t = squishCon cfv t
                                                  (*val () = Print.prefaces "squishExp"
                                                                          [("e", ElabPrint.p_exp E.empty e)]*)
                                                  val e = squishExp (0(*nr*), cfv, efv) e

                                                  val (e, t) = foldl (fn (ex, (e, t)) =>
                                                                         let
                                                                             val (name, t') = List.nth (ts, ex)
                                                                         in
                                                                             ((EAbs (name,
                                                                                     t',
                                                                                     t,
                                                                                     e), loc),
                                                                              (TFun (t',
                                                                                     t), loc))
                                                                         end)
                                                                     (e, t) efv

                                                  val (e, t) = foldl (fn (cx, (e, t)) =>
                                                                         let
                                                                             val (name, k) = List.nth (ks, cx)
                                                                         in
                                                                             ((ECAbs (Explicit,
                                                                                      name,
                                                                                      k,
                                                                                      e), loc),
                                                                              (TCFun (Explicit,
                                                                                      name,
                                                                                      k,
                                                                                      t), loc))
                                                                         end)
                                                                     (e, t) cfv
                                              in
                                                  (x, n, t, e)
                                              end)
                                          vis

                            val ts = map (fn (x, _, t, _) => (x, t)) vis @ ts
                        in
                            ([], (ts, maxName, vis @ ds, subs))
                        end)
                (ts, #maxName st, #decls st, []) eds
        in
            (ELet (eds, doSubst e subs),
             {maxName = maxName,
              decls = ds})
        end

      | _ => (e, st)

fun default (ctx, d, st) = (d, st)

fun bind ((ks, ts), b) =
    case b of
        U.Decl.RelC p => (p :: ks, map (fn (name, t) => (name, E.liftConInCon 0 t)) ts)
      | U.Decl.RelE p => (ks, p :: ts)
      | _ => (ks, ts)                        

val unnestDecl = U.Decl.foldMapB {kind = kind,
                                  con = default,
                                  exp = exp,
                                  sgn_item = default,
                                  sgn = default,
                                  str = default,
                                  decl = default,
                                  bind = bind}
                                 ([], [])

fun unnest file =
    let
        fun doDecl (all as (d, loc), st : state) =
            let
                fun default () = ([all], st)
                fun explore () =
                    let
                        val (d, st) = unnestDecl st all

                        val ds =
                            case #1 d of
                                DValRec vis => [(DValRec (vis @ #decls st), #2 d)]
                              | _ => [(DValRec (#decls st), #2 d), d]
                    in
                        (ds,
                         {maxName = #maxName st,
                          decls = []})
                    end
            in
                case d of
                    DCon _ => default ()
                  | DDatatype _ => default ()
                  | DDatatypeImp _ => default ()
                  | DVal _ => explore ()
                  | DValRec _ => explore ()
                  | DSgn _ => default ()
                  | DStr (x, n, sgn, str) =>
                    let
                        val (str, st) = doStr (str, st)
                    in
                        ([(DStr (x, n, sgn, str), loc)], st)
                    end
                  | DFfiStr _ => default ()
                  | DConstraint _ => default ()
                  | DExport _ => default ()
                  | DTable _ => default ()
                  | DSequence _ => default ()
                  | DClass _ => default ()
                  | DDatabase _ => default ()
            end

        and doStr (all as (str, loc), st) =
            let
                fun default () = (all, st)
            in
                case str of
                    StrConst ds =>
                    let
                        val (ds, st) = ListUtil.foldlMapConcat doDecl st ds
                    in
                        ((StrConst ds, loc), st)
                    end
                  | StrVar _ => default ()
                  | StrProj _ => default ()
                  | StrFun (x, n, dom, ran, str) =>
                    let
                        val (str, st) = doStr (str, st)
                    in
                        ((StrFun (x, n, dom, ran, str), loc), st)
                    end
                  | StrApp _ => default ()
                  | StrError => raise Fail "Unnest: StrError"
            end

        val (ds, _) = ListUtil.foldlMapConcat doDecl
                      {maxName = U.File.maxName file + 1,
                       decls = []} file
    in
        ds
    end

end