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Lifting cons in ElabEnv
author Adam Chlipala <adamc@hcoop.net>
date Sun, 08 Jun 2008 11:32:48 -0400
parents d89477f07c1e
children f1c36df29ed7
rev   line source
adamc@2 1 (* Copyright (c) 2008, Adam Chlipala
adamc@2 2 * All rights reserved.
adamc@2 3 *
adamc@2 4 * Redistribution and use in source and binary forms, with or without
adamc@2 5 * modification, are permitted provided that the following conditions are met:
adamc@2 6 *
adamc@2 7 * - Redistributions of source code must retain the above copyright notice,
adamc@2 8 * this list of conditions and the following disclaimer.
adamc@2 9 * - Redistributions in binary form must reproduce the above copyright notice,
adamc@2 10 * this list of conditions and the following disclaimer in the documentation
adamc@2 11 * and/or other materials provided with the distribution.
adamc@2 12 * - The names of contributors may not be used to endorse or promote products
adamc@2 13 * derived from this software without specific prior written permission.
adamc@2 14 *
adamc@2 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
adamc@2 16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
adamc@2 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
adamc@2 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
adamc@2 19 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
adamc@2 20 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
adamc@2 21 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
adamc@2 22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
adamc@2 23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
adamc@2 24 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
adamc@2 25 * POSSIBILITY OF SUCH DAMAGE.
adamc@2 26 *)
adamc@2 27
adamc@2 28 structure Elaborate :> ELABORATE = struct
adamc@2 29
adamc@4 30 structure L = Source
adamc@2 31 structure L' = Elab
adamc@2 32 structure E = ElabEnv
adamc@2 33 structure U = ElabUtil
adamc@2 34
adamc@3 35 open Print
adamc@3 36 open ElabPrint
adamc@3 37
adamc@2 38 fun elabKind (k, loc) =
adamc@2 39 case k of
adamc@2 40 L.KType => (L'.KType, loc)
adamc@2 41 | L.KArrow (k1, k2) => (L'.KArrow (elabKind k1, elabKind k2), loc)
adamc@2 42 | L.KName => (L'.KName, loc)
adamc@2 43 | L.KRecord k => (L'.KRecord (elabKind k), loc)
adamc@2 44
adamc@2 45 fun elabExplicitness e =
adamc@2 46 case e of
adamc@2 47 L.Explicit => L'.Explicit
adamc@2 48 | L.Implicit => L'.Implicit
adamc@2 49
adamc@2 50 fun occursKind r =
adamc@2 51 U.Kind.exists (fn L'.KUnif (_, r') => r = r'
adamc@2 52 | _ => false)
adamc@2 53
adamc@3 54 datatype kunify_error =
adamc@2 55 KOccursCheckFailed of L'.kind * L'.kind
adamc@2 56 | KIncompatible of L'.kind * L'.kind
adamc@2 57
adamc@3 58 exception KUnify' of kunify_error
adamc@3 59
adamc@3 60 fun kunifyError err =
adamc@2 61 case err of
adamc@2 62 KOccursCheckFailed (k1, k2) =>
adamc@3 63 eprefaces "Kind occurs check failed"
adamc@3 64 [("Kind 1", p_kind k1),
adamc@3 65 ("Kind 2", p_kind k2)]
adamc@2 66 | KIncompatible (k1, k2) =>
adamc@3 67 eprefaces "Incompatible kinds"
adamc@3 68 [("Kind 1", p_kind k1),
adamc@3 69 ("Kind 2", p_kind k2)]
adamc@2 70
adamc@3 71 fun unifyKinds' (k1All as (k1, _)) (k2All as (k2, _)) =
adamc@2 72 let
adamc@3 73 fun err f = raise KUnify' (f (k1All, k2All))
adamc@2 74 in
adamc@2 75 case (k1, k2) of
adamc@2 76 (L'.KType, L'.KType) => ()
adamc@2 77 | (L'.KArrow (d1, r1), L'.KArrow (d2, r2)) =>
adamc@3 78 (unifyKinds' d1 d2;
adamc@3 79 unifyKinds' r1 r2)
adamc@2 80 | (L'.KName, L'.KName) => ()
adamc@3 81 | (L'.KRecord k1, L'.KRecord k2) => unifyKinds' k1 k2
adamc@2 82
adamc@2 83 | (L'.KError, _) => ()
adamc@2 84 | (_, L'.KError) => ()
adamc@2 85
adamc@3 86 | (L'.KUnif (_, ref (SOME k1All)), _) => unifyKinds' k1All k2All
adamc@3 87 | (_, L'.KUnif (_, ref (SOME k2All))) => unifyKinds' k1All k2All
adamc@2 88
adamc@2 89 | (L'.KUnif (_, r1), L'.KUnif (_, r2)) =>
adamc@2 90 if r1 = r2 then
adamc@2 91 ()
adamc@2 92 else
adamc@2 93 r1 := SOME k2All
adamc@2 94
adamc@2 95 | (L'.KUnif (_, r), _) =>
adamc@2 96 if occursKind r k2All then
adamc@2 97 err KOccursCheckFailed
adamc@2 98 else
adamc@2 99 r := SOME k2All
adamc@2 100 | (_, L'.KUnif (_, r)) =>
adamc@2 101 if occursKind r k1All then
adamc@2 102 err KOccursCheckFailed
adamc@2 103 else
adamc@2 104 r := SOME k1All
adamc@2 105
adamc@2 106 | _ => err KIncompatible
adamc@2 107 end
adamc@2 108
adamc@3 109 exception KUnify of L'.kind * L'.kind * kunify_error
adamc@3 110
adamc@3 111 fun unifyKinds k1 k2 =
adamc@3 112 unifyKinds' k1 k2
adamc@3 113 handle KUnify' err => raise KUnify (k1, k2, err)
adamc@3 114
adamc@3 115 datatype con_error =
adamc@3 116 UnboundCon of ErrorMsg.span * string
adamc@3 117 | WrongKind of L'.con * L'.kind * L'.kind * kunify_error
adamc@3 118
adamc@5 119 fun conError env err =
adamc@3 120 case err of
adamc@3 121 UnboundCon (loc, s) =>
adamc@3 122 ErrorMsg.errorAt loc ("Unbound constructor variable " ^ s)
adamc@3 123 | WrongKind (c, k1, k2, kerr) =>
adamc@3 124 (ErrorMsg.errorAt (#2 c) "Wrong kind";
adamc@5 125 eprefaces' [("Constructor", p_con env c),
adamc@5 126 ("Have kind", p_kind k1),
adamc@5 127 ("Need kind", p_kind k2)];
adamc@3 128 kunifyError kerr)
adamc@3 129
adamc@5 130 fun checkKind env c k1 k2 =
adamc@3 131 unifyKinds k1 k2
adamc@3 132 handle KUnify (k1, k2, err) =>
adamc@5 133 conError env (WrongKind (c, k1, k2, err))
adamc@3 134
adamc@3 135 val dummy = ErrorMsg.dummySpan
adamc@3 136
adamc@3 137 val ktype = (L'.KType, dummy)
adamc@3 138 val kname = (L'.KName, dummy)
adamc@12 139 val ktype_record = (L'.KRecord ktype, dummy)
adamc@3 140
adamc@3 141 val cerror = (L'.CError, dummy)
adamc@3 142 val kerror = (L'.KError, dummy)
adamc@10 143 val eerror = (L'.EError, dummy)
adamc@3 144
adamc@3 145 local
adamc@3 146 val count = ref 0
adamc@3 147 in
adamc@3 148
adamc@3 149 fun resetKunif () = count := 0
adamc@3 150
adamc@3 151 fun kunif () =
adamc@3 152 let
adamc@3 153 val n = !count
adamc@3 154 val s = if n <= 26 then
adamc@3 155 str (chr (ord #"A" + n))
adamc@3 156 else
adamc@3 157 "U" ^ Int.toString (n - 26)
adamc@3 158 in
adamc@3 159 count := n + 1;
adamc@3 160 (L'.KUnif (s, ref NONE), dummy)
adamc@3 161 end
adamc@3 162
adamc@3 163 end
adamc@3 164
adamc@10 165 local
adamc@10 166 val count = ref 0
adamc@10 167 in
adamc@10 168
adamc@10 169 fun resetCunif () = count := 0
adamc@10 170
adamc@10 171 fun cunif k =
adamc@10 172 let
adamc@10 173 val n = !count
adamc@10 174 val s = if n <= 26 then
adamc@10 175 str (chr (ord #"A" + n))
adamc@10 176 else
adamc@10 177 "U" ^ Int.toString (n - 26)
adamc@10 178 in
adamc@10 179 count := n + 1;
adamc@10 180 (L'.CUnif (k, s, ref NONE), dummy)
adamc@10 181 end
adamc@10 182
adamc@10 183 end
adamc@10 184
adamc@3 185 fun elabCon env (c, loc) =
adamc@3 186 case c of
adamc@3 187 L.CAnnot (c, k) =>
adamc@3 188 let
adamc@3 189 val k' = elabKind k
adamc@3 190 val (c', ck) = elabCon env c
adamc@3 191 in
adamc@5 192 checkKind env c' ck k';
adamc@3 193 (c', k')
adamc@3 194 end
adamc@3 195
adamc@3 196 | L.TFun (t1, t2) =>
adamc@3 197 let
adamc@3 198 val (t1', k1) = elabCon env t1
adamc@3 199 val (t2', k2) = elabCon env t2
adamc@3 200 in
adamc@5 201 checkKind env t1' k1 ktype;
adamc@5 202 checkKind env t2' k2 ktype;
adamc@3 203 ((L'.TFun (t1', t2'), loc), ktype)
adamc@3 204 end
adamc@3 205 | L.TCFun (e, x, k, t) =>
adamc@3 206 let
adamc@3 207 val e' = elabExplicitness e
adamc@3 208 val k' = elabKind k
adamc@3 209 val env' = E.pushCRel env x k'
adamc@3 210 val (t', tk) = elabCon env' t
adamc@3 211 in
adamc@5 212 checkKind env t' tk ktype;
adamc@3 213 ((L'.TCFun (e', x, k', t'), loc), ktype)
adamc@3 214 end
adamc@3 215 | L.TRecord c =>
adamc@3 216 let
adamc@3 217 val (c', ck) = elabCon env c
adamc@3 218 val k = (L'.KRecord ktype, loc)
adamc@3 219 in
adamc@5 220 checkKind env c' ck k;
adamc@3 221 ((L'.TRecord c', loc), ktype)
adamc@3 222 end
adamc@3 223
adamc@3 224 | L.CVar s =>
adamc@3 225 (case E.lookupC env s of
adamc@9 226 E.NotBound =>
adamc@5 227 (conError env (UnboundCon (loc, s));
adamc@3 228 (cerror, kerror))
adamc@9 229 | E.Rel (n, k) =>
adamc@3 230 ((L'.CRel n, loc), k)
adamc@9 231 | E.Named (n, k) =>
adamc@3 232 ((L'.CNamed n, loc), k))
adamc@3 233 | L.CApp (c1, c2) =>
adamc@3 234 let
adamc@3 235 val (c1', k1) = elabCon env c1
adamc@3 236 val (c2', k2) = elabCon env c2
adamc@3 237 val dom = kunif ()
adamc@3 238 val ran = kunif ()
adamc@3 239 in
adamc@5 240 checkKind env c1' k1 (L'.KArrow (dom, ran), loc);
adamc@5 241 checkKind env c2' k2 dom;
adamc@3 242 ((L'.CApp (c1', c2'), loc), ran)
adamc@3 243 end
adamc@8 244 | L.CAbs (x, k, t) =>
adamc@3 245 let
adamc@3 246 val k' = elabKind k
adamc@3 247 val env' = E.pushCRel env x k'
adamc@3 248 val (t', tk) = elabCon env' t
adamc@3 249 in
adamc@8 250 ((L'.CAbs (x, k', t'), loc),
adamc@3 251 (L'.KArrow (k', tk), loc))
adamc@3 252 end
adamc@3 253
adamc@3 254 | L.CName s =>
adamc@3 255 ((L'.CName s, loc), kname)
adamc@3 256
adamc@3 257 | L.CRecord xcs =>
adamc@3 258 let
adamc@3 259 val k = kunif ()
adamc@3 260
adamc@3 261 val xcs' = map (fn (x, c) =>
adamc@3 262 let
adamc@3 263 val (x', xk) = elabCon env x
adamc@3 264 val (c', ck) = elabCon env c
adamc@3 265 in
adamc@5 266 checkKind env x' xk kname;
adamc@5 267 checkKind env c' ck k;
adamc@3 268 (x', c')
adamc@3 269 end) xcs
adamc@3 270 in
adamc@5 271 ((L'.CRecord (k, xcs'), loc), (L'.KRecord k, loc))
adamc@3 272 end
adamc@3 273 | L.CConcat (c1, c2) =>
adamc@3 274 let
adamc@3 275 val (c1', k1) = elabCon env c1
adamc@3 276 val (c2', k2) = elabCon env c2
adamc@3 277 val ku = kunif ()
adamc@3 278 val k = (L'.KRecord ku, loc)
adamc@3 279 in
adamc@5 280 checkKind env c1' k1 k;
adamc@5 281 checkKind env c2' k2 k;
adamc@3 282 ((L'.CConcat (c1', c2'), loc), k)
adamc@3 283 end
adamc@3 284
adamc@6 285 fun kunifsRemain k =
adamc@6 286 case k of
adamc@6 287 L'.KUnif (_, ref NONE) => true
adamc@6 288 | _ => false
adamc@10 289 fun cunifsRemain c =
adamc@10 290 case c of
adamc@10 291 L'.CUnif (_, _, ref NONE) => true
adamc@10 292 | _ => false
adamc@6 293
adamc@6 294 val kunifsInKind = U.Kind.exists kunifsRemain
adamc@6 295 val kunifsInCon = U.Con.exists {kind = kunifsRemain,
adamc@6 296 con = fn _ => false}
adamc@10 297 val kunifsInExp = U.Exp.exists {kind = kunifsRemain,
adamc@10 298 con = fn _ => false,
adamc@10 299 exp = fn _ => false}
adamc@10 300
adamc@10 301 val cunifsInCon = U.Con.exists {kind = fn _ => false,
adamc@10 302 con = cunifsRemain}
adamc@10 303 val cunifsInExp = U.Exp.exists {kind = fn _ => false,
adamc@10 304 con = cunifsRemain,
adamc@10 305 exp = fn _ => false}
adamc@10 306
adamc@10 307 fun occursCon r =
adamc@10 308 U.Con.exists {kind = fn _ => false,
adamc@10 309 con = fn L'.CUnif (_, _, r') => r = r'
adamc@10 310 | _ => false}
adamc@10 311
adamc@10 312 datatype cunify_error =
adamc@10 313 CKind of L'.kind * L'.kind * kunify_error
adamc@10 314 | COccursCheckFailed of L'.con * L'.con
adamc@10 315 | CIncompatible of L'.con * L'.con
adamc@10 316 | CExplicitness of L'.con * L'.con
adamc@12 317 | CKindof of L'.con
adamc@12 318 | CRecordFailure
adamc@10 319
adamc@10 320 exception CUnify' of cunify_error
adamc@10 321
adamc@10 322 fun cunifyError env err =
adamc@10 323 case err of
adamc@10 324 CKind (k1, k2, kerr) =>
adamc@10 325 (eprefaces "Kind unification failure"
adamc@10 326 [("Kind 1", p_kind k1),
adamc@10 327 ("Kind 2", p_kind k2)];
adamc@10 328 kunifyError kerr)
adamc@10 329 | COccursCheckFailed (c1, c2) =>
adamc@10 330 eprefaces "Constructor occurs check failed"
adamc@10 331 [("Con 1", p_con env c1),
adamc@10 332 ("Con 2", p_con env c2)]
adamc@10 333 | CIncompatible (c1, c2) =>
adamc@10 334 eprefaces "Incompatible constructors"
adamc@10 335 [("Con 1", p_con env c1),
adamc@10 336 ("Con 2", p_con env c2)]
adamc@10 337 | CExplicitness (c1, c2) =>
adamc@10 338 eprefaces "Differing constructor function explicitness"
adamc@10 339 [("Con 1", p_con env c1),
adamc@10 340 ("Con 2", p_con env c2)]
adamc@12 341 | CKindof c =>
adamc@12 342 eprefaces "Kind unification variable blocks kindof calculation"
adamc@12 343 [("Con", p_con env c)]
adamc@12 344 | CRecordFailure =>
adamc@12 345 eprefaces "Can't unify record constructors" []
adamc@10 346
adamc@13 347 exception SynUnif = E.SynUnif
adamc@13 348 val liftConInCon = E.liftConInCon
adamc@12 349
adamc@12 350 val subConInCon =
adamc@12 351 U.Con.mapB {kind = fn k => k,
adamc@12 352 con = fn (xn, rep) => fn c =>
adamc@12 353 case c of
adamc@12 354 L'.CRel xn' =>
adamc@12 355 if xn = xn' then
adamc@12 356 #1 rep
adamc@12 357 else
adamc@12 358 c
adamc@12 359 | L'.CUnif _ => raise SynUnif
adamc@12 360 | _ => c,
adamc@12 361 bind = fn ((xn, rep), U.Con.Rel _) => (xn+1, liftConInCon 0 rep)
adamc@12 362 | (ctx, _) => ctx}
adamc@12 363
adamc@12 364 type record_summary = {
adamc@12 365 fields : (L'.con * L'.con) list,
adamc@12 366 unifs : (L'.con * L'.con option ref) list,
adamc@12 367 others : L'.con list
adamc@12 368 }
adamc@12 369
adamc@12 370 fun summaryToCon {fields, unifs, others} =
adamc@12 371 let
adamc@12 372 val c = (L'.CRecord (ktype, []), dummy)
adamc@12 373 val c = List.foldr (fn (c', c) => (L'.CConcat (c', c), dummy)) c others
adamc@12 374 val c = List.foldr (fn ((c', _), c) => (L'.CConcat (c', c), dummy)) c unifs
adamc@12 375 in
adamc@12 376 (L'.CConcat ((L'.CRecord (ktype, fields), dummy), c), dummy)
adamc@12 377 end
adamc@12 378
adamc@12 379 fun p_summary env s = p_con env (summaryToCon s)
adamc@12 380
adamc@12 381 exception CUnify of L'.con * L'.con * cunify_error
adamc@12 382
adamc@12 383 fun hnormKind (kAll as (k, _)) =
adamc@12 384 case k of
adamc@12 385 L'.KUnif (_, ref (SOME k)) => hnormKind k
adamc@12 386 | _ => kAll
adamc@12 387
adamc@12 388 fun kindof env (c, loc) =
adamc@12 389 case c of
adamc@12 390 L'.TFun _ => ktype
adamc@12 391 | L'.TCFun _ => ktype
adamc@12 392 | L'.TRecord _ => ktype
adamc@12 393
adamc@12 394 | L'.CRel xn => #2 (E.lookupCRel env xn)
adamc@12 395 | L'.CNamed xn => #2 (E.lookupCNamed env xn)
adamc@12 396 | L'.CApp (c, _) =>
adamc@12 397 (case #1 (hnormKind (kindof env c)) of
adamc@12 398 L'.KArrow (_, k) => k
adamc@12 399 | L'.KError => kerror
adamc@12 400 | _ => raise CUnify' (CKindof c))
adamc@12 401 | L'.CAbs (x, k, c) => (L'.KArrow (k, kindof (E.pushCRel env x k) c), loc)
adamc@12 402
adamc@12 403 | L'.CName _ => kname
adamc@12 404
adamc@12 405 | L'.CRecord (k, _) => (L'.KRecord k, loc)
adamc@12 406 | L'.CConcat (c, _) => kindof env c
adamc@12 407
adamc@12 408 | L'.CError => kerror
adamc@12 409 | L'.CUnif (k, _, _) => k
adamc@12 410
adamc@12 411 fun unifyRecordCons env (c1, c2) =
adamc@12 412 let
adamc@12 413 val k1 = kindof env c1
adamc@12 414 val k2 = kindof env c2
adamc@12 415 in
adamc@12 416 unifyKinds k1 k2;
adamc@12 417 unifySummaries env (k1, recordSummary env c1, recordSummary env c2)
adamc@12 418 end
adamc@12 419
adamc@12 420 and recordSummary env c : record_summary =
adamc@12 421 case hnormCon env c of
adamc@12 422 (L'.CRecord (_, xcs), _) => {fields = xcs, unifs = [], others = []}
adamc@12 423 | (L'.CConcat (c1, c2), _) =>
adamc@12 424 let
adamc@12 425 val s1 = recordSummary env c1
adamc@12 426 val s2 = recordSummary env c2
adamc@12 427 in
adamc@12 428 {fields = #fields s1 @ #fields s2,
adamc@12 429 unifs = #unifs s1 @ #unifs s2,
adamc@12 430 others = #others s1 @ #others s2}
adamc@12 431 end
adamc@12 432 | (L'.CUnif (_, _, ref (SOME c)), _) => recordSummary env c
adamc@12 433 | c' as (L'.CUnif (_, _, r), _) => {fields = [], unifs = [(c', r)], others = []}
adamc@12 434 | c' => {fields = [], unifs = [], others = [c']}
adamc@12 435
adamc@12 436 and consEq env (c1, c2) =
adamc@12 437 (unifyCons env c1 c2;
adamc@12 438 true)
adamc@12 439 handle CUnify _ => false
adamc@12 440
adamc@12 441 and unifySummaries env (k, s1 : record_summary, s2 : record_summary) =
adamc@12 442 let
adamc@12 443 val () = eprefaces "Summaries" [("#1", p_summary env s1),
adamc@12 444 ("#2", p_summary env s2)]
adamc@12 445
adamc@12 446 fun eatMatching p (ls1, ls2) =
adamc@12 447 let
adamc@12 448 fun em (ls1, ls2, passed1) =
adamc@12 449 case ls1 of
adamc@12 450 [] => (rev passed1, ls2)
adamc@12 451 | h1 :: t1 =>
adamc@12 452 let
adamc@12 453 fun search (ls2', passed2) =
adamc@12 454 case ls2' of
adamc@12 455 [] => em (t1, ls2, h1 :: passed1)
adamc@12 456 | h2 :: t2 =>
adamc@12 457 if p (h1, h2) then
adamc@12 458 em (t1, List.revAppend (passed2, t2), passed1)
adamc@12 459 else
adamc@12 460 search (t2, h2 :: passed2)
adamc@12 461 in
adamc@12 462 search (ls2, [])
adamc@12 463 end
adamc@12 464 in
adamc@12 465 em (ls1, ls2, [])
adamc@12 466 end
adamc@12 467
adamc@12 468 val (fs1, fs2) = eatMatching (fn ((x1, c1), (x2, c2)) =>
adamc@12 469 if consEq env (x1, x2) then
adamc@12 470 (unifyCons env c1 c2;
adamc@12 471 true)
adamc@12 472 else
adamc@12 473 false) (#fields s1, #fields s2)
adamc@12 474 val () = eprefaces "Summaries2" [("#1", p_summary env {fields = fs1, unifs = #unifs s1, others = #others s1}),
adamc@12 475 ("#2", p_summary env {fields = fs2, unifs = #unifs s2, others = #others s2})]
adamc@12 476 val (unifs1, unifs2) = eatMatching (fn ((_, r1), (_, r2)) => r1 = r2) (#unifs s1, #unifs s2)
adamc@12 477 val (others1, others2) = eatMatching (consEq env) (#others s1, #others s2)
adamc@12 478
adamc@12 479 fun unifFields (fs, others, unifs) =
adamc@12 480 case (fs, others, unifs) of
adamc@12 481 ([], [], _) => ([], [], unifs)
adamc@12 482 | (_, _, []) => (fs, others, [])
adamc@12 483 | (_, _, (_, r) :: rest) =>
adamc@12 484 let
adamc@12 485 val r' = ref NONE
adamc@12 486 val cr' = (L'.CUnif (k, "recd", r'), dummy)
adamc@12 487
adamc@12 488 val prefix = case (fs, others) of
adamc@12 489 ([], other :: others) =>
adamc@12 490 List.foldl (fn (other, c) =>
adamc@12 491 (L'.CConcat (c, other), dummy))
adamc@12 492 other others
adamc@12 493 | (fs, []) =>
adamc@12 494 (L'.CRecord (k, fs), dummy)
adamc@12 495 | (fs, others) =>
adamc@12 496 List.foldl (fn (other, c) =>
adamc@12 497 (L'.CConcat (c, other), dummy))
adamc@12 498 (L'.CRecord (k, fs), dummy) others
adamc@12 499 in
adamc@12 500 r := SOME (L'.CConcat (prefix, cr'), dummy);
adamc@12 501 ([], [], (cr', r') :: rest)
adamc@12 502 end
adamc@12 503
adamc@12 504 val (fs1, others1, unifs2) = unifFields (fs1, others1, unifs2)
adamc@12 505 val (fs2, others2, unifs1) = unifFields (fs2, others2, unifs1)
adamc@12 506
adamc@12 507 val clear1 = case (fs1, others1) of
adamc@12 508 ([], []) => true
adamc@12 509 | _ => false
adamc@12 510 val clear2 = case (fs2, others2) of
adamc@12 511 ([], []) => true
adamc@12 512 | _ => false
adamc@12 513 val empty = (L'.CRecord (k, []), dummy)
adamc@12 514 fun pairOffUnifs (unifs1, unifs2) =
adamc@12 515 case (unifs1, unifs2) of
adamc@12 516 ([], _) =>
adamc@12 517 if clear1 then
adamc@12 518 List.app (fn (_, r) => r := SOME empty) unifs2
adamc@12 519 else
adamc@12 520 raise CUnify' CRecordFailure
adamc@12 521 | (_, []) =>
adamc@12 522 if clear2 then
adamc@12 523 List.app (fn (_, r) => r := SOME empty) unifs1
adamc@12 524 else
adamc@12 525 raise CUnify' CRecordFailure
adamc@12 526 | ((c1, _) :: rest1, (_, r2) :: rest2) =>
adamc@12 527 (r2 := SOME c1;
adamc@12 528 pairOffUnifs (rest1, rest2))
adamc@12 529 in
adamc@12 530 pairOffUnifs (unifs1, unifs2)
adamc@12 531 end
adamc@12 532
adamc@12 533 and hnormCon env (cAll as (c, _)) =
adamc@11 534 case c of
adamc@11 535 L'.CUnif (_, _, ref (SOME c)) => hnormCon env c
adamc@11 536
adamc@11 537 | L'.CNamed xn =>
adamc@11 538 (case E.lookupCNamed env xn of
adamc@11 539 (_, _, SOME c') => hnormCon env c'
adamc@11 540 | _ => cAll)
adamc@11 541
adamc@12 542 | L'.CApp (c1, c2) =>
adamc@12 543 (case hnormCon env c1 of
adamc@12 544 (L'.CAbs (_, _, cb), _) =>
adamc@12 545 ((hnormCon env (subConInCon (0, c2) cb))
adamc@12 546 handle SynUnif => cAll)
adamc@12 547 | _ => cAll)
adamc@12 548
adamc@12 549 | L'.CConcat (c1, c2) =>
adamc@12 550 (case (hnormCon env c1, hnormCon env c2) of
adamc@12 551 ((L'.CRecord (k, xcs1), loc), (L'.CRecord (_, xcs2), _)) =>
adamc@12 552 (L'.CRecord (k, xcs1 @ xcs2), loc)
adamc@12 553 | _ => cAll)
adamc@12 554
adamc@11 555 | _ => cAll
adamc@11 556
adamc@12 557 and unifyCons' env c1 c2 =
adamc@11 558 unifyCons'' env (hnormCon env c1) (hnormCon env c2)
adamc@11 559
adamc@11 560 and unifyCons'' env (c1All as (c1, _)) (c2All as (c2, _)) =
adamc@10 561 let
adamc@10 562 fun err f = raise CUnify' (f (c1All, c2All))
adamc@12 563
adamc@12 564 fun isRecord () = unifyRecordCons env (c1All, c2All)
adamc@10 565 in
adamc@10 566 case (c1, c2) of
adamc@10 567 (L'.TFun (d1, r1), L'.TFun (d2, r2)) =>
adamc@10 568 (unifyCons' env d1 d2;
adamc@10 569 unifyCons' env r1 r2)
adamc@10 570 | (L'.TCFun (expl1, x1, d1, r1), L'.TCFun (expl2, _, d2, r2)) =>
adamc@10 571 if expl1 <> expl2 then
adamc@10 572 err CExplicitness
adamc@10 573 else
adamc@10 574 (unifyKinds d1 d2;
adamc@10 575 unifyCons' (E.pushCRel env x1 d1) r1 r2)
adamc@10 576 | (L'.TRecord r1, L'.TRecord r2) => unifyCons' env r1 r2
adamc@10 577
adamc@10 578 | (L'.CRel n1, L'.CRel n2) =>
adamc@10 579 if n1 = n2 then
adamc@10 580 ()
adamc@10 581 else
adamc@10 582 err CIncompatible
adamc@10 583 | (L'.CNamed n1, L'.CNamed n2) =>
adamc@10 584 if n1 = n2 then
adamc@10 585 ()
adamc@10 586 else
adamc@10 587 err CIncompatible
adamc@10 588
adamc@10 589 | (L'.CApp (d1, r1), L'.CApp (d2, r2)) =>
adamc@10 590 (unifyCons' env d1 d2;
adamc@10 591 unifyCons' env r1 r2)
adamc@10 592 | (L'.CAbs (x1, k1, c1), L'.CAbs (_, k2, c2)) =>
adamc@10 593 (unifyKinds k1 k2;
adamc@10 594 unifyCons' (E.pushCRel env x1 k1) c1 c2)
adamc@10 595
adamc@10 596 | (L'.CName n1, L'.CName n2) =>
adamc@10 597 if n1 = n2 then
adamc@10 598 ()
adamc@10 599 else
adamc@10 600 err CIncompatible
adamc@10 601
adamc@10 602 | (L'.CError, _) => ()
adamc@10 603 | (_, L'.CError) => ()
adamc@10 604
adamc@10 605 | (L'.CUnif (_, _, ref (SOME c1All)), _) => unifyCons' env c1All c2All
adamc@10 606 | (_, L'.CUnif (_, _, ref (SOME c2All))) => unifyCons' env c1All c2All
adamc@10 607
adamc@10 608 | (L'.CUnif (k1, _, r1), L'.CUnif (k2, _, r2)) =>
adamc@10 609 if r1 = r2 then
adamc@10 610 ()
adamc@10 611 else
adamc@10 612 (unifyKinds k1 k2;
adamc@10 613 r1 := SOME c2All)
adamc@10 614
adamc@10 615 | (L'.CUnif (_, _, r), _) =>
adamc@10 616 if occursCon r c2All then
adamc@10 617 err COccursCheckFailed
adamc@10 618 else
adamc@10 619 r := SOME c2All
adamc@10 620 | (_, L'.CUnif (_, _, r)) =>
adamc@10 621 if occursCon r c1All then
adamc@10 622 err COccursCheckFailed
adamc@10 623 else
adamc@10 624 r := SOME c1All
adamc@10 625
adamc@12 626 | (L'.CRecord _, _) => isRecord ()
adamc@12 627 | (_, L'.CRecord _) => isRecord ()
adamc@12 628 | (L'.CConcat _, _) => isRecord ()
adamc@12 629 | (_, L'.CConcat _) => isRecord ()
adamc@12 630
adamc@10 631 | _ => err CIncompatible
adamc@10 632 end
adamc@10 633
adamc@12 634 and unifyCons env c1 c2 =
adamc@10 635 unifyCons' env c1 c2
adamc@10 636 handle CUnify' err => raise CUnify (c1, c2, err)
adamc@10 637 | KUnify args => raise CUnify (c1, c2, CKind args)
adamc@10 638
adamc@10 639 datatype exp_error =
adamc@10 640 UnboundExp of ErrorMsg.span * string
adamc@10 641 | Unify of L'.exp * L'.con * L'.con * cunify_error
adamc@11 642 | Unif of string * L'.con
adamc@11 643 | WrongForm of string * L'.exp * L'.con
adamc@10 644
adamc@10 645 fun expError env err =
adamc@10 646 case err of
adamc@10 647 UnboundExp (loc, s) =>
adamc@10 648 ErrorMsg.errorAt loc ("Unbound expression variable " ^ s)
adamc@10 649 | Unify (e, c1, c2, uerr) =>
adamc@10 650 (ErrorMsg.errorAt (#2 e) "Unification failure";
adamc@10 651 eprefaces' [("Expression", p_exp env e),
adamc@10 652 ("Have con", p_con env c1),
adamc@10 653 ("Need con", p_con env c2)];
adamc@10 654 cunifyError env uerr)
adamc@11 655 | Unif (action, c) =>
adamc@11 656 (ErrorMsg.errorAt (#2 c) ("Unification variable blocks " ^ action);
adamc@11 657 eprefaces' [("Con", p_con env c)])
adamc@11 658 | WrongForm (variety, e, t) =>
adamc@11 659 (ErrorMsg.errorAt (#2 e) ("Expression is not a " ^ variety);
adamc@11 660 eprefaces' [("Expression", p_exp env e),
adamc@11 661 ("Type", p_con env t)])
adamc@10 662
adamc@10 663 fun checkCon env e c1 c2 =
adamc@10 664 unifyCons env c1 c2
adamc@10 665 handle CUnify (c1, c2, err) =>
adamc@10 666 expError env (Unify (e, c1, c2, err))
adamc@10 667
adamc@10 668 fun elabExp env (e, loc) =
adamc@10 669 case e of
adamc@10 670 L.EAnnot (e, t) =>
adamc@10 671 let
adamc@10 672 val (e', et) = elabExp env e
adamc@10 673 val (t', _) = elabCon env t
adamc@10 674 in
adamc@10 675 checkCon env e' et t';
adamc@10 676 (e', t')
adamc@10 677 end
adamc@10 678
adamc@10 679 | L.EVar s =>
adamc@10 680 (case E.lookupE env s of
adamc@10 681 E.NotBound =>
adamc@10 682 (expError env (UnboundExp (loc, s));
adamc@10 683 (eerror, cerror))
adamc@10 684 | E.Rel (n, t) => ((L'.ERel n, loc), t)
adamc@10 685 | E.Named (n, t) => ((L'.ENamed n, loc), t))
adamc@10 686 | L.EApp (e1, e2) =>
adamc@10 687 let
adamc@10 688 val (e1', t1) = elabExp env e1
adamc@10 689 val (e2', t2) = elabExp env e2
adamc@10 690
adamc@10 691 val dom = cunif ktype
adamc@10 692 val ran = cunif ktype
adamc@10 693 val t = (L'.TFun (dom, ran), dummy)
adamc@10 694 in
adamc@10 695 checkCon env e1' t1 t;
adamc@10 696 checkCon env e2' t2 dom;
adamc@10 697 ((L'.EApp (e1', e2'), loc), ran)
adamc@10 698 end
adamc@10 699 | L.EAbs (x, to, e) =>
adamc@10 700 let
adamc@10 701 val t' = case to of
adamc@10 702 NONE => cunif ktype
adamc@10 703 | SOME t =>
adamc@10 704 let
adamc@10 705 val (t', tk) = elabCon env t
adamc@10 706 in
adamc@10 707 checkKind env t' tk ktype;
adamc@10 708 t'
adamc@10 709 end
adamc@10 710 val (e', et) = elabExp (E.pushERel env x t') e
adamc@10 711 in
adamc@10 712 ((L'.EAbs (x, t', e'), loc),
adamc@10 713 (L'.TFun (t', et), loc))
adamc@10 714 end
adamc@10 715 | L.ECApp (e, c) =>
adamc@10 716 let
adamc@10 717 val (e', et) = elabExp env e
adamc@10 718 val (c', ck) = elabCon env c
adamc@10 719 in
adamc@11 720 case #1 (hnormCon env et) of
adamc@11 721 L'.CError => (eerror, cerror)
adamc@11 722 | L'.TCFun (_, _, k, eb) =>
adamc@11 723 let
adamc@11 724 val () = checkKind env c' ck k
adamc@11 725 val eb' = subConInCon (0, c') eb
adamc@11 726 handle SynUnif => (expError env (Unif ("substitution", eb));
adamc@11 727 cerror)
adamc@11 728 in
adamc@11 729 ((L'.ECApp (e', c'), loc), eb')
adamc@11 730 end
adamc@11 731
adamc@11 732 | L'.CUnif _ =>
adamc@11 733 (expError env (Unif ("application", et));
adamc@11 734 (eerror, cerror))
adamc@11 735
adamc@11 736 | _ =>
adamc@11 737 (expError env (WrongForm ("constructor function", e', et));
adamc@11 738 (eerror, cerror))
adamc@10 739 end
adamc@11 740 | L.ECAbs (expl, x, k, e) =>
adamc@11 741 let
adamc@11 742 val expl' = elabExplicitness expl
adamc@11 743 val k' = elabKind k
adamc@11 744 val (e', et) = elabExp (E.pushCRel env x k') e
adamc@11 745 in
adamc@11 746 ((L'.ECAbs (expl', x, k', e'), loc),
adamc@11 747 (L'.TCFun (expl', x, k', et), loc))
adamc@11 748 end
adamc@6 749
adamc@12 750 | L.ERecord xes =>
adamc@12 751 let
adamc@12 752 val xes' = map (fn (x, e) =>
adamc@12 753 let
adamc@12 754 val (x', xk) = elabCon env x
adamc@12 755 val (e', et) = elabExp env e
adamc@12 756 in
adamc@12 757 checkKind env x' xk kname;
adamc@12 758 (x', e', et)
adamc@12 759 end) xes
adamc@12 760 in
adamc@12 761 ((L'.ERecord (map (fn (x', e', _) => (x', e')) xes'), loc),
adamc@12 762 (L'.TRecord (L'.CRecord (ktype, map (fn (x', _, et) => (x', et)) xes'), loc), loc))
adamc@12 763 end
adamc@12 764
adamc@12 765 | L.EField (e, c) =>
adamc@12 766 let
adamc@12 767 val (e', et) = elabExp env e
adamc@12 768 val (c', ck) = elabCon env c
adamc@12 769
adamc@12 770 val ft = cunif ktype
adamc@12 771 val rest = cunif ktype_record
adamc@12 772 in
adamc@12 773 checkKind env c' ck kname;
adamc@12 774 checkCon env e' et (L'.TRecord (L'.CConcat ((L'.CRecord (ktype, [(c', ft)]), loc), rest), loc), loc);
adamc@12 775 ((L'.EField (e', c', {field = ft, rest = rest}), loc), ft)
adamc@12 776 end
adamc@12 777
adamc@12 778
adamc@6 779 datatype decl_error =
adamc@6 780 KunifsRemainKind of ErrorMsg.span * L'.kind
adamc@6 781 | KunifsRemainCon of ErrorMsg.span * L'.con
adamc@10 782 | KunifsRemainExp of ErrorMsg.span * L'.exp
adamc@10 783 | CunifsRemainCon of ErrorMsg.span * L'.con
adamc@10 784 | CunifsRemainExp of ErrorMsg.span * L'.exp
adamc@6 785
adamc@6 786 fun declError env err =
adamc@6 787 case err of
adamc@6 788 KunifsRemainKind (loc, k) =>
adamc@6 789 (ErrorMsg.errorAt loc "Some kind unification variables are undetermined in kind";
adamc@6 790 eprefaces' [("Kind", p_kind k)])
adamc@6 791 | KunifsRemainCon (loc, c) =>
adamc@6 792 (ErrorMsg.errorAt loc "Some kind unification variables are undetermined in constructor";
adamc@6 793 eprefaces' [("Constructor", p_con env c)])
adamc@10 794 | KunifsRemainExp (loc, e) =>
adamc@10 795 (ErrorMsg.errorAt loc "Some kind unification variables are undetermined in expression";
adamc@10 796 eprefaces' [("Expression", p_exp env e)])
adamc@10 797 | CunifsRemainCon (loc, c) =>
adamc@10 798 (ErrorMsg.errorAt loc "Some constructor unification variables are undetermined in constructor";
adamc@10 799 eprefaces' [("Constructor", p_con env c)])
adamc@10 800 | CunifsRemainExp (loc, e) =>
adamc@10 801 (ErrorMsg.errorAt loc "Some constructor unification variables are undetermined in expression";
adamc@10 802 eprefaces' [("Expression", p_exp env e)])
adamc@6 803
adamc@3 804 fun elabDecl env (d, loc) =
adamc@5 805 (resetKunif ();
adamc@12 806 resetCunif ();
adamc@5 807 case d of
adamc@5 808 L.DCon (x, ko, c) =>
adamc@5 809 let
adamc@5 810 val k' = case ko of
adamc@5 811 NONE => kunif ()
adamc@5 812 | SOME k => elabKind k
adamc@3 813
adamc@5 814 val (c', ck) = elabCon env c
adamc@11 815 val (env', n) = E.pushCNamed env x k' (SOME c')
adamc@5 816 in
adamc@5 817 checkKind env c' ck k';
adamc@6 818
adamc@6 819 if kunifsInKind k' then
adamc@6 820 declError env (KunifsRemainKind (loc, k'))
adamc@6 821 else
adamc@6 822 ();
adamc@6 823
adamc@6 824 if kunifsInCon c' then
adamc@6 825 declError env (KunifsRemainCon (loc, c'))
adamc@6 826 else
adamc@6 827 ();
adamc@6 828
adamc@5 829 (env',
adamc@5 830 (L'.DCon (x, n, k', c'), loc))
adamc@10 831 end
adamc@10 832 | L.DVal (x, co, e) =>
adamc@10 833 let
adamc@10 834 val (c', ck) = case co of
adamc@10 835 NONE => (cunif ktype, ktype)
adamc@10 836 | SOME c => elabCon env c
adamc@10 837
adamc@10 838 val (e', et) = elabExp env e
adamc@10 839 val (env', n) = E.pushENamed env x c'
adamc@10 840 in
adamc@10 841 checkCon env e' et c';
adamc@10 842
adamc@10 843 if kunifsInCon c' then
adamc@10 844 declError env (KunifsRemainCon (loc, c'))
adamc@10 845 else
adamc@10 846 ();
adamc@10 847
adamc@10 848 if cunifsInCon c' then
adamc@10 849 declError env (CunifsRemainCon (loc, c'))
adamc@10 850 else
adamc@10 851 ();
adamc@10 852
adamc@10 853 if kunifsInExp e' then
adamc@10 854 declError env (KunifsRemainExp (loc, e'))
adamc@10 855 else
adamc@10 856 ();
adamc@10 857
adamc@10 858 if cunifsInExp e' then
adamc@10 859 declError env (CunifsRemainExp (loc, e'))
adamc@10 860 else
adamc@10 861 ();
adamc@10 862
adamc@10 863 (env',
adamc@10 864 (L'.DVal (x, n, c', e'), loc))
adamc@5 865 end)
adamc@3 866
adamc@5 867 fun elabFile env ds =
adamc@5 868 ListUtil.mapfoldl (fn (d, env) => elabDecl env d) env ds
adamc@2 869
adamc@2 870 end