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annotate src/unnest.sml @ 1639:6c00d8af6239

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Add a new scoping check for unification variables, to fix a type inference bug
author Adam Chlipala <adam@chlipala.net>
date Sun, 18 Dec 2011 11:29:13 -0500
parents b4480a56cab7
children bb942416bf1c
rev   line source
adamc@1272 1 (* Copyright (c) 2008-2010, Adam Chlipala
adamc@448 2 * All rights reserved.
adamc@448 3 *
adamc@448 4 * Redistribution and use in source and binary forms, with or without
adamc@448 5 * modification, are permitted provided that the following conditions are met:
adamc@448 6 *
adamc@448 7 * - Redistributions of source code must retain the above copyright notice,
adamc@448 8 * this list of conditions and the following disclaimer.
adamc@448 9 * - Redistributions in binary form must reproduce the above copyright notice,
adamc@448 10 * this list of conditions and the following disclaimer in the documentation
adamc@448 11 * and/or other materials provided with the distribution.
adamc@448 12 * - The names of contributors may not be used to endorse or promote products
adamc@448 13 * derived from this software without specific prior written permission.
adamc@448 14 *
adamc@448 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
adamc@448 16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
adamc@448 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
adamc@448 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
adamc@448 19 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
adamc@448 20 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
adamc@448 21 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
adamc@448 22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
adamc@448 23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
adamc@448 24 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
adamc@448 25 * POSSIBILITY OF SUCH DAMAGE.
adamc@448 26 *)
adamc@448 27
adamc@448 28 (* Remove nested function definitions *)
adamc@448 29
adamc@448 30 structure Unnest :> UNNEST = struct
adamc@448 31
adamc@448 32 open Elab
adamc@448 33
adamc@448 34 structure E = ElabEnv
adamc@448 35 structure U = ElabUtil
adamc@448 36
adamc@448 37 structure IS = IntBinarySet
adamc@448 38
adamc@487 39 fun liftExpInExp by =
adamc@623 40 U.Exp.mapB {kind = fn _ => fn k => k,
adamc@487 41 con = fn _ => fn c => c,
adamc@487 42 exp = fn bound => fn e =>
adamc@487 43 case e of
adamc@487 44 ERel xn =>
adamc@487 45 if xn < bound then
adamc@487 46 e
adamc@487 47 else
adamc@487 48 ERel (xn + by)
adamc@487 49 | _ => e,
adamc@487 50 bind = fn (bound, U.Exp.RelE _) => bound + 1
adamc@487 51 | (bound, _) => bound}
adamc@487 52
adamc@487 53 val subExpInExp =
adamc@623 54 U.Exp.mapB {kind = fn _ => fn k => k,
adamc@487 55 con = fn _ => fn c => c,
adamc@487 56 exp = fn (xn, rep) => fn e =>
adamc@487 57 case e of
adamc@487 58 ERel xn' =>
adamc@487 59 if xn' = xn then
adamc@487 60 #1 rep
adamc@487 61 else
adamc@487 62 e
adamc@487 63 | _ => e,
adamc@487 64 bind = fn ((xn, rep), U.Exp.RelE _) => (xn+1, E.liftExpInExp 0 rep)
adamc@487 65 | ((xn, rep), U.Exp.RelC _) => (xn, E.liftConInExp 0 rep)
adamc@487 66 | (ctx, _) => ctx}
adamc@487 67
adamc@623 68 val fvsCon = U.Con.foldB {kind = fn (_, _, st) => st,
adamc@448 69 con = fn (cb, c, cvs) =>
adamc@448 70 case c of
adamc@448 71 CRel n =>
adamc@448 72 if n >= cb then
adamc@448 73 IS.add (cvs, n - cb)
adamc@448 74 else
adamc@448 75 cvs
adamc@448 76 | _ => cvs,
adamc@448 77 bind = fn (cb, b) =>
adamc@448 78 case b of
adamc@623 79 U.Con.RelC _ => cb + 1
adamc@448 80 | _ => cb}
adamc@448 81 0 IS.empty
adamc@448 82
adamc@623 83 fun fvsExp nr = U.Exp.foldB {kind = fn (_, _, st) => st,
adamc@448 84 con = fn ((cb, eb), c, st as (cvs, evs)) =>
adamc@448 85 case c of
adamc@448 86 CRel n =>
adamc@448 87 if n >= cb then
adamc@448 88 (IS.add (cvs, n - cb), evs)
adamc@448 89 else
adamc@448 90 st
adamc@448 91 | _ => st,
adamc@448 92 exp = fn ((cb, eb), e, st as (cvs, evs)) =>
adamc@448 93 case e of
adamc@448 94 ERel n =>
adamc@448 95 if n >= eb then
adamc@448 96 (cvs, IS.add (evs, n - eb))
adamc@448 97 else
adamc@448 98 st
adamc@448 99 | _ => st,
adamc@448 100 bind = fn (ctx as (cb, eb), b) =>
adamc@448 101 case b of
adamc@448 102 U.Exp.RelC _ => (cb + 1, eb)
adamc@448 103 | U.Exp.RelE _ => (cb, eb + 1)
adamc@448 104 | _ => ctx}
adamc@448 105 (0, nr) (IS.empty, IS.empty)
adamc@448 106
adamc@448 107 fun positionOf (x : int) ls =
adamc@448 108 let
adamc@448 109 fun po n ls =
adamc@448 110 case ls of
adamc@448 111 [] => raise Fail "Unnest.positionOf"
adamc@448 112 | x' :: ls' =>
adamc@448 113 if x' = x then
adamc@448 114 n
adamc@448 115 else
adamc@448 116 po (n + 1) ls'
adamc@448 117 in
adamc@448 118 po 0 ls
adamc@487 119 handle Fail _ => raise Fail ("Unnest.positionOf("
adamc@448 120 ^ Int.toString x
adamc@448 121 ^ ", "
adamc@448 122 ^ String.concatWith ";" (map Int.toString ls)
adamc@448 123 ^ ")")
adamc@448 124 end
adamc@448 125
adamc@448 126 fun squishCon cfv =
adamc@623 127 U.Con.mapB {kind = fn _ => fn k => k,
adamc@448 128 con = fn cb => fn c =>
adamc@448 129 case c of
adamc@448 130 CRel n =>
adamc@448 131 if n >= cb then
adamc@448 132 CRel (positionOf (n - cb) cfv + cb)
adamc@448 133 else
adamc@448 134 c
adamc@448 135 | _ => c,
adamc@448 136 bind = fn (cb, b) =>
adamc@448 137 case b of
adamc@623 138 U.Con.RelC _ => cb + 1
adamc@448 139 | _ => cb}
adamc@448 140 0
adamc@448 141
adamc@448 142 fun squishExp (nr, cfv, efv) =
adamc@623 143 U.Exp.mapB {kind = fn _ => fn k => k,
adamc@448 144 con = fn (cb, eb) => fn c =>
adamc@448 145 case c of
adamc@448 146 CRel n =>
adamc@448 147 if n >= cb then
adamc@448 148 CRel (positionOf (n - cb) cfv + cb)
adamc@448 149 else
adamc@448 150 c
adamc@448 151 | _ => c,
adamc@448 152 exp = fn (cb, eb) => fn e =>
adamc@448 153 case e of
adamc@448 154 ERel n =>
adamc@448 155 if n >= eb then
adamc@487 156 ERel (positionOf (n - eb) efv + eb - nr)
adamc@448 157 else
adamc@448 158 e
adamc@448 159 | _ => e,
adamc@448 160 bind = fn (ctx as (cb, eb), b) =>
adamc@448 161 case b of
adamc@448 162 U.Exp.RelC _ => (cb + 1, eb)
adamc@448 163 | U.Exp.RelE _ => (cb, eb + 1)
adamc@448 164 | _ => ctx}
adamc@448 165 (0, nr)
adamc@448 166
adamc@448 167 type state = {
adamc@448 168 maxName : int,
adamc@455 169 decls : (string * int * con * exp) list
adamc@448 170 }
adamc@448 171
adamc@623 172 fun kind (_, k, st) = (k, st)
adamc@448 173
adamc@453 174 fun exp ((ks, ts), e as old, st : state) =
adamc@448 175 case e of
adamc@825 176 ELet (eds, e, t) =>
adamc@448 177 let
adamc@487 178 (*val () = Print.prefaces "Letto" [("e", ElabPrint.p_exp E.empty (old, ErrorMsg.dummySpan))]*)
adamc@453 179
adamc@487 180 fun doSubst' (e, subs) = foldl (fn (p, e) => subExpInExp p e) e subs
adamc@448 181
adamc@487 182 fun doSubst (e, subs, by) =
adamc@487 183 let
adamc@487 184 val e = doSubst' (e, subs)
adamc@487 185 in
adamc@487 186 liftExpInExp (~by) (length subs) e
adamc@487 187 end
adamc@487 188
adamc@487 189 val (eds, (ts, maxName, ds, subs, by)) =
adamc@448 190 ListUtil.foldlMapConcat
adamc@487 191 (fn (ed, (ts, maxName, ds, subs, by)) =>
adamc@448 192 case #1 ed of
adamc@825 193 EDVal (p, t, e) =>
adamc@487 194 let
adamc@487 195 val e = doSubst (e, subs, by)
adamc@825 196
adamc@825 197 fun doVars ((p, _), ts) =
adamc@825 198 case p of
adamc@825 199 PWild => ts
adamc@825 200 | PVar xt => xt :: ts
adamc@825 201 | PPrim _ => ts
adamc@825 202 | PCon (_, _, _, NONE) => ts
adamc@825 203 | PCon (_, _, _, SOME p) => doVars (p, ts)
adamc@825 204 | PRecord xpcs =>
adamc@825 205 foldl (fn ((_, p, _), ts) => doVars (p, ts))
adamc@825 206 ts xpcs
adamc@1272 207
adamc@1272 208 fun bindOne subs = ((0, (ERel 0, #2 ed))
adamc@1272 209 :: map (fn (n, e) => (n + 1, E.liftExpInExp 0 e)) subs)
adamc@1272 210
adamc@1272 211 fun bindMany (n, subs) =
adamc@1272 212 case n of
adamc@1272 213 0 => subs
adamc@1272 214 | _ => bindMany (n - 1, bindOne subs)
adamc@487 215 in
adamc@825 216 ([(EDVal (p, t, e), #2 ed)],
adamc@825 217 (doVars (p, ts),
adamc@487 218 maxName, ds,
adamc@1272 219 bindMany (E.patBindsN p, subs),
adamc@487 220 by))
adamc@487 221 end
adamc@448 222 | EDValRec vis =>
adamc@448 223 let
adamc@448 224 val loc = #2 ed
adamc@448 225
adamc@448 226 val nr = length vis
adamc@490 227 val subsLocal = List.filter (fn (_, (ERel _, _)) => false
adamc@490 228 | _ => true) subs
adamc@490 229 val subsLocal = map (fn (n, e) => (n + nr, liftExpInExp nr 0 e))
adamc@490 230 subsLocal
adamc@490 231
adamc@490 232 val vis = map (fn (x, t, e) =>
adamc@490 233 (x, t, doSubst' (e, subsLocal))) vis
adamc@490 234
adamc@448 235 val (cfv, efv) = foldl (fn ((_, t, e), (cfv, efv)) =>
adamc@448 236 let
adamc@448 237 val (cfv', efv') = fvsExp nr e
adamc@448 238 (*val () = Print.prefaces "fvsExp"
adamc@448 239 [("e", ElabPrint.p_exp E.empty e),
adamc@448 240 ("cfv", Print.PD.string
adamc@448 241 (Int.toString (IS.numItems cfv'))),
adamc@448 242 ("efv", Print.PD.string
adamc@448 243 (Int.toString (IS.numItems efv')))]*)
adamc@448 244 val cfv'' = fvsCon t
adamc@448 245 in
adamc@448 246 (IS.union (cfv, IS.union (cfv', cfv'')),
adamc@448 247 IS.union (efv, efv'))
adamc@448 248 end)
adamc@448 249 (IS.empty, IS.empty) vis
adamc@448 250
adamc@826 251 (*val () = Print.prefaces "Letto" [("e", ElabPrint.p_exp E.empty (old, ErrorMsg.dummySpan))]*)
adamc@826 252 (*val () = print ("A: " ^ Int.toString (length ts) ^ ", " ^ Int.toString (length ks) ^ "\n")*)
adamc@826 253 (*val () = app (fn (x, t) =>
adamc@453 254 Print.prefaces "Var" [("x", Print.PD.string x),
adamc@826 255 ("t", ElabPrint.p_con E.empty t)]) ts
adamc@826 256 val () = IS.app (fn n => print ("Free: " ^ Int.toString n ^ "\n")) efv*)
adamc@487 257
adamc@448 258 val cfv = IS.foldl (fn (x, cfv) =>
adamc@448 259 let
adamc@448 260 (*val () = print (Int.toString x ^ "\n")*)
adamc@448 261 val (_, t) = List.nth (ts, x)
adamc@448 262 in
adamc@448 263 IS.union (cfv, fvsCon t)
adamc@448 264 end)
adamc@448 265 cfv efv
adamc@448 266 (*val () = print "B\n"*)
adamc@448 267
adamc@448 268 val (vis, maxName) =
adamc@448 269 ListUtil.foldlMap (fn ((x, t, e), maxName) =>
adamc@448 270 ((x, maxName, t, e),
adamc@448 271 maxName + 1))
adamc@448 272 maxName vis
adamc@448 273
adamc@487 274 val subs = map (fn (n, e) => (n + nr,
adamc@487 275 case e of
adamc@487 276 (ERel _, _) => e
adamc@487 277 | _ => liftExpInExp nr 0 e))
adamc@487 278 subs
adamc@487 279
adamc@448 280 val subs' = ListUtil.mapi (fn (i, (_, n, _, _)) =>
adamc@448 281 let
adamc@487 282 val e = (ENamed n, loc)
adamc@487 283
adamc@487 284 val e = IS.foldr (fn (x, e) =>
adamc@487 285 (ECApp (e, (CRel x, loc)), loc))
adamc@487 286 e cfv
adamc@487 287
adamc@487 288 val e = IS.foldr (fn (x, e) =>
adamc@487 289 (EApp (e, (ERel (nr + x), loc)),
adamc@487 290 loc))
adamc@487 291 e efv
adamc@448 292 in
adamc@487 293 (nr - i - 1, e)
adamc@448 294 end)
adamc@450 295 vis
adamc@450 296
adamc@448 297 val cfv = IS.listItems cfv
adamc@448 298 val efv = IS.listItems efv
adamc@448 299
adamc@487 300 val subs = subs' @ subs
adamc@448 301
adamc@448 302 val vis = map (fn (x, n, t, e) =>
adamc@448 303 let
adamc@448 304 (*val () = Print.prefaces "preSubst"
adamc@448 305 [("e", ElabPrint.p_exp E.empty e)]*)
adamc@490 306 val e = doSubst' (e, subs')
adamc@448 307
adamc@448 308 (*val () = Print.prefaces "squishCon"
adamc@448 309 [("t", ElabPrint.p_con E.empty t)]*)
adamc@448 310 val t = squishCon cfv t
adamc@448 311 (*val () = Print.prefaces "squishExp"
adamc@448 312 [("e", ElabPrint.p_exp E.empty e)]*)
adamc@487 313 val e = squishExp (nr, cfv, efv) e
adamc@448 314
adamc@487 315 (*val () = print ("Avail: " ^ Int.toString (length ts) ^ "\n")*)
adamc@453 316 val (e, t) = foldl (fn (ex, (e, t)) =>
adamc@448 317 let
adamc@487 318 (*val () = print (Int.toString ex ^ "\n")*)
adamc@448 319 val (name, t') = List.nth (ts, ex)
adamc@1272 320 val t' = squishCon cfv t'
adamc@448 321 in
adamc@448 322 ((EAbs (name,
adamc@448 323 t',
adamc@448 324 t,
adamc@448 325 e), loc),
adamc@448 326 (TFun (t',
adamc@448 327 t), loc))
adamc@448 328 end)
adamc@448 329 (e, t) efv
adamc@487 330 (*val () = print "Done\n"*)
adamc@448 331
adamc@453 332 val (e, t) = foldl (fn (cx, (e, t)) =>
adamc@448 333 let
adamc@448 334 val (name, k) = List.nth (ks, cx)
adamc@448 335 in
adamc@448 336 ((ECAbs (Explicit,
adamc@448 337 name,
adamc@448 338 k,
adamc@448 339 e), loc),
adamc@448 340 (TCFun (Explicit,
adamc@448 341 name,
adamc@448 342 k,
adamc@448 343 t), loc))
adamc@448 344 end)
adamc@448 345 (e, t) cfv
adamc@448 346 in
adamc@487 347 (*Print.prefaces "Have a vi"
adamc@487 348 [("x", Print.PD.string x),
adamc@487 349 ("e", ElabPrint.p_exp ElabEnv.empty e)];*)
adamc@1017 350 ("$" ^ x, n, t, e)
adamc@448 351 end)
adamc@448 352 vis
adamc@448 353
adamc@487 354 val ts = List.revAppend (map (fn (x, _, t, _) => (x, t)) vis, ts)
adamc@448 355 in
adamc@487 356 ([], (ts, maxName, vis @ ds, subs, by + nr))
adamc@448 357 end)
adamc@487 358 (ts, #maxName st, #decls st, [], 0) eds
adamc@487 359
adamc@487 360 val e' = doSubst (e, subs, by)
adamc@448 361 in
adamc@487 362 (*Print.prefaces "Before" [("e", ElabPrint.p_exp ElabEnv.empty e),
adamc@487 363 ("se", ElabPrint.p_exp ElabEnv.empty (doSubst' (e, subs))),
adamc@487 364 ("e'", ElabPrint.p_exp ElabEnv.empty e')];*)
adamc@1272 365 (*Print.prefaces "Let" [("Before", ElabPrint.p_exp ElabEnv.empty (old, ErrorMsg.dummySpan)),
adamc@1272 366 ("After", ElabPrint.p_exp ElabEnv.empty (ELet (eds, e', t), ErrorMsg.dummySpan))];*)
adamc@825 367 (ELet (eds, e', t),
adamc@448 368 {maxName = maxName,
adamc@448 369 decls = ds})
adamc@487 370 (*(ELet (eds, doSubst (liftExpInExp (~(length subs - numRemaining)) (length subs) e) subs),*)
adamc@448 371 end
adamc@448 372
adamc@448 373 | _ => (e, st)
adamc@448 374
adamc@448 375 fun default (ctx, d, st) = (d, st)
adamc@448 376
adamc@448 377 fun bind ((ks, ts), b) =
adamc@448 378 case b of
adamc@448 379 U.Decl.RelC p => (p :: ks, map (fn (name, t) => (name, E.liftConInCon 0 t)) ts)
adamc@448 380 | U.Decl.RelE p => (ks, p :: ts)
adamc@448 381 | _ => (ks, ts)
adamc@448 382
adamc@448 383 val unnestDecl = U.Decl.foldMapB {kind = kind,
adamc@448 384 con = default,
adamc@448 385 exp = exp,
adamc@448 386 sgn_item = default,
adamc@448 387 sgn = default,
adamc@448 388 str = default,
adamc@448 389 decl = default,
adamc@448 390 bind = bind}
adamc@448 391 ([], [])
adamc@448 392
adamc@448 393 fun unnest file =
adamc@448 394 let
adamc@448 395 fun doDecl (all as (d, loc), st : state) =
adamc@448 396 let
adamc@448 397 fun default () = ([all], st)
adamc@448 398 fun explore () =
adamc@448 399 let
adamc@448 400 val (d, st) = unnestDecl st all
adamc@455 401
adamc@455 402 val ds =
adamc@455 403 case #1 d of
adamc@455 404 DValRec vis => [(DValRec (vis @ #decls st), #2 d)]
adamc@455 405 | _ => [(DValRec (#decls st), #2 d), d]
adamc@448 406 in
adamc@455 407 (ds,
adamc@448 408 {maxName = #maxName st,
adamc@448 409 decls = []})
adamc@448 410 end
adamc@448 411 in
adamc@448 412 case d of
adamc@448 413 DCon _ => default ()
adamc@448 414 | DDatatype _ => default ()
adamc@448 415 | DDatatypeImp _ => default ()
adamc@448 416 | DVal _ => explore ()
adamc@448 417 | DValRec _ => explore ()
adamc@448 418 | DSgn _ => default ()
adamc@448 419 | DStr (x, n, sgn, str) =>
adamc@448 420 let
adamc@448 421 val (str, st) = doStr (str, st)
adamc@448 422 in
adamc@448 423 ([(DStr (x, n, sgn, str), loc)], st)
adamc@448 424 end
adamc@448 425 | DFfiStr _ => default ()
adamc@448 426 | DConstraint _ => default ()
adamc@448 427 | DExport _ => default ()
adamc@448 428 | DTable _ => default ()
adamc@448 429 | DSequence _ => default ()
adamc@754 430 | DView _ => default ()
adamc@448 431 | DClass _ => default ()
adamc@448 432 | DDatabase _ => default ()
adamc@459 433 | DCookie _ => default ()
adamc@718 434 | DStyle _ => default ()
adamc@1075 435 | DTask _ => explore ()
adamc@1199 436 | DPolicy _ => explore ()
adam@1294 437 | DOnError _ => default ()
adamc@448 438 end
adamc@448 439
adamc@448 440 and doStr (all as (str, loc), st) =
adamc@448 441 let
adamc@448 442 fun default () = (all, st)
adamc@448 443 in
adamc@448 444 case str of
adamc@448 445 StrConst ds =>
adamc@448 446 let
adamc@448 447 val (ds, st) = ListUtil.foldlMapConcat doDecl st ds
adamc@448 448 in
adamc@448 449 ((StrConst ds, loc), st)
adamc@448 450 end
adamc@448 451 | StrVar _ => default ()
adamc@448 452 | StrProj _ => default ()
adamc@448 453 | StrFun (x, n, dom, ran, str) =>
adamc@448 454 let
adamc@448 455 val (str, st) = doStr (str, st)
adamc@448 456 in
adamc@448 457 ((StrFun (x, n, dom, ran, str), loc), st)
adamc@448 458 end
adamc@448 459 | StrApp _ => default ()
adamc@448 460 | StrError => raise Fail "Unnest: StrError"
adamc@448 461 end
adamc@448 462
adamc@448 463 val (ds, _) = ListUtil.foldlMapConcat doDecl
adamc@448 464 {maxName = U.File.maxName file + 1,
adamc@448 465 decls = []} file
adamc@448 466 in
adamc@448 467 ds
adamc@448 468 end
adamc@448 469
adamc@448 470 end