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annotate src/elaborate.sml @ 12:d89477f07c1e

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Fun with records
author Adam Chlipala <adamc@hcoop.net>
date Fri, 28 Mar 2008 17:34:57 -0400
parents e97c6d335869
children 6049e2193bf2
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@12 347 exception SynUnif
adamc@12 348
adamc@12 349 val liftConInCon =
adamc@12 350 U.Con.mapB {kind = fn k => k,
adamc@12 351 con = fn bound => fn c =>
adamc@12 352 case c of
adamc@12 353 L'.CRel xn =>
adamc@12 354 if xn < bound then
adamc@12 355 c
adamc@12 356 else
adamc@12 357 L'.CRel (xn + 1)
adamc@12 358 | L'.CUnif _ => raise SynUnif
adamc@12 359 | _ => c,
adamc@12 360 bind = fn (bound, U.Con.Rel _) => bound + 1
adamc@12 361 | (bound, _) => bound}
adamc@12 362
adamc@12 363 val subConInCon =
adamc@12 364 U.Con.mapB {kind = fn k => k,
adamc@12 365 con = fn (xn, rep) => fn c =>
adamc@12 366 case c of
adamc@12 367 L'.CRel xn' =>
adamc@12 368 if xn = xn' then
adamc@12 369 #1 rep
adamc@12 370 else
adamc@12 371 c
adamc@12 372 | L'.CUnif _ => raise SynUnif
adamc@12 373 | _ => c,
adamc@12 374 bind = fn ((xn, rep), U.Con.Rel _) => (xn+1, liftConInCon 0 rep)
adamc@12 375 | (ctx, _) => ctx}
adamc@12 376
adamc@12 377 type record_summary = {
adamc@12 378 fields : (L'.con * L'.con) list,
adamc@12 379 unifs : (L'.con * L'.con option ref) list,
adamc@12 380 others : L'.con list
adamc@12 381 }
adamc@12 382
adamc@12 383 fun summaryToCon {fields, unifs, others} =
adamc@12 384 let
adamc@12 385 val c = (L'.CRecord (ktype, []), dummy)
adamc@12 386 val c = List.foldr (fn (c', c) => (L'.CConcat (c', c), dummy)) c others
adamc@12 387 val c = List.foldr (fn ((c', _), c) => (L'.CConcat (c', c), dummy)) c unifs
adamc@12 388 in
adamc@12 389 (L'.CConcat ((L'.CRecord (ktype, fields), dummy), c), dummy)
adamc@12 390 end
adamc@12 391
adamc@12 392 fun p_summary env s = p_con env (summaryToCon s)
adamc@12 393
adamc@12 394 exception CUnify of L'.con * L'.con * cunify_error
adamc@12 395
adamc@12 396 fun hnormKind (kAll as (k, _)) =
adamc@12 397 case k of
adamc@12 398 L'.KUnif (_, ref (SOME k)) => hnormKind k
adamc@12 399 | _ => kAll
adamc@12 400
adamc@12 401 fun kindof env (c, loc) =
adamc@12 402 case c of
adamc@12 403 L'.TFun _ => ktype
adamc@12 404 | L'.TCFun _ => ktype
adamc@12 405 | L'.TRecord _ => ktype
adamc@12 406
adamc@12 407 | L'.CRel xn => #2 (E.lookupCRel env xn)
adamc@12 408 | L'.CNamed xn => #2 (E.lookupCNamed env xn)
adamc@12 409 | L'.CApp (c, _) =>
adamc@12 410 (case #1 (hnormKind (kindof env c)) of
adamc@12 411 L'.KArrow (_, k) => k
adamc@12 412 | L'.KError => kerror
adamc@12 413 | _ => raise CUnify' (CKindof c))
adamc@12 414 | L'.CAbs (x, k, c) => (L'.KArrow (k, kindof (E.pushCRel env x k) c), loc)
adamc@12 415
adamc@12 416 | L'.CName _ => kname
adamc@12 417
adamc@12 418 | L'.CRecord (k, _) => (L'.KRecord k, loc)
adamc@12 419 | L'.CConcat (c, _) => kindof env c
adamc@12 420
adamc@12 421 | L'.CError => kerror
adamc@12 422 | L'.CUnif (k, _, _) => k
adamc@12 423
adamc@12 424 fun unifyRecordCons env (c1, c2) =
adamc@12 425 let
adamc@12 426 val k1 = kindof env c1
adamc@12 427 val k2 = kindof env c2
adamc@12 428 in
adamc@12 429 unifyKinds k1 k2;
adamc@12 430 unifySummaries env (k1, recordSummary env c1, recordSummary env c2)
adamc@12 431 end
adamc@12 432
adamc@12 433 and recordSummary env c : record_summary =
adamc@12 434 case hnormCon env c of
adamc@12 435 (L'.CRecord (_, xcs), _) => {fields = xcs, unifs = [], others = []}
adamc@12 436 | (L'.CConcat (c1, c2), _) =>
adamc@12 437 let
adamc@12 438 val s1 = recordSummary env c1
adamc@12 439 val s2 = recordSummary env c2
adamc@12 440 in
adamc@12 441 {fields = #fields s1 @ #fields s2,
adamc@12 442 unifs = #unifs s1 @ #unifs s2,
adamc@12 443 others = #others s1 @ #others s2}
adamc@12 444 end
adamc@12 445 | (L'.CUnif (_, _, ref (SOME c)), _) => recordSummary env c
adamc@12 446 | c' as (L'.CUnif (_, _, r), _) => {fields = [], unifs = [(c', r)], others = []}
adamc@12 447 | c' => {fields = [], unifs = [], others = [c']}
adamc@12 448
adamc@12 449 and consEq env (c1, c2) =
adamc@12 450 (unifyCons env c1 c2;
adamc@12 451 true)
adamc@12 452 handle CUnify _ => false
adamc@12 453
adamc@12 454 and unifySummaries env (k, s1 : record_summary, s2 : record_summary) =
adamc@12 455 let
adamc@12 456 val () = eprefaces "Summaries" [("#1", p_summary env s1),
adamc@12 457 ("#2", p_summary env s2)]
adamc@12 458
adamc@12 459 fun eatMatching p (ls1, ls2) =
adamc@12 460 let
adamc@12 461 fun em (ls1, ls2, passed1) =
adamc@12 462 case ls1 of
adamc@12 463 [] => (rev passed1, ls2)
adamc@12 464 | h1 :: t1 =>
adamc@12 465 let
adamc@12 466 fun search (ls2', passed2) =
adamc@12 467 case ls2' of
adamc@12 468 [] => em (t1, ls2, h1 :: passed1)
adamc@12 469 | h2 :: t2 =>
adamc@12 470 if p (h1, h2) then
adamc@12 471 em (t1, List.revAppend (passed2, t2), passed1)
adamc@12 472 else
adamc@12 473 search (t2, h2 :: passed2)
adamc@12 474 in
adamc@12 475 search (ls2, [])
adamc@12 476 end
adamc@12 477 in
adamc@12 478 em (ls1, ls2, [])
adamc@12 479 end
adamc@12 480
adamc@12 481 val (fs1, fs2) = eatMatching (fn ((x1, c1), (x2, c2)) =>
adamc@12 482 if consEq env (x1, x2) then
adamc@12 483 (unifyCons env c1 c2;
adamc@12 484 true)
adamc@12 485 else
adamc@12 486 false) (#fields s1, #fields s2)
adamc@12 487 val () = eprefaces "Summaries2" [("#1", p_summary env {fields = fs1, unifs = #unifs s1, others = #others s1}),
adamc@12 488 ("#2", p_summary env {fields = fs2, unifs = #unifs s2, others = #others s2})]
adamc@12 489 val (unifs1, unifs2) = eatMatching (fn ((_, r1), (_, r2)) => r1 = r2) (#unifs s1, #unifs s2)
adamc@12 490 val (others1, others2) = eatMatching (consEq env) (#others s1, #others s2)
adamc@12 491
adamc@12 492 fun unifFields (fs, others, unifs) =
adamc@12 493 case (fs, others, unifs) of
adamc@12 494 ([], [], _) => ([], [], unifs)
adamc@12 495 | (_, _, []) => (fs, others, [])
adamc@12 496 | (_, _, (_, r) :: rest) =>
adamc@12 497 let
adamc@12 498 val r' = ref NONE
adamc@12 499 val cr' = (L'.CUnif (k, "recd", r'), dummy)
adamc@12 500
adamc@12 501 val prefix = case (fs, others) of
adamc@12 502 ([], other :: others) =>
adamc@12 503 List.foldl (fn (other, c) =>
adamc@12 504 (L'.CConcat (c, other), dummy))
adamc@12 505 other others
adamc@12 506 | (fs, []) =>
adamc@12 507 (L'.CRecord (k, fs), dummy)
adamc@12 508 | (fs, others) =>
adamc@12 509 List.foldl (fn (other, c) =>
adamc@12 510 (L'.CConcat (c, other), dummy))
adamc@12 511 (L'.CRecord (k, fs), dummy) others
adamc@12 512 in
adamc@12 513 r := SOME (L'.CConcat (prefix, cr'), dummy);
adamc@12 514 ([], [], (cr', r') :: rest)
adamc@12 515 end
adamc@12 516
adamc@12 517 val (fs1, others1, unifs2) = unifFields (fs1, others1, unifs2)
adamc@12 518 val (fs2, others2, unifs1) = unifFields (fs2, others2, unifs1)
adamc@12 519
adamc@12 520 val clear1 = case (fs1, others1) of
adamc@12 521 ([], []) => true
adamc@12 522 | _ => false
adamc@12 523 val clear2 = case (fs2, others2) of
adamc@12 524 ([], []) => true
adamc@12 525 | _ => false
adamc@12 526 val empty = (L'.CRecord (k, []), dummy)
adamc@12 527 fun pairOffUnifs (unifs1, unifs2) =
adamc@12 528 case (unifs1, unifs2) of
adamc@12 529 ([], _) =>
adamc@12 530 if clear1 then
adamc@12 531 List.app (fn (_, r) => r := SOME empty) unifs2
adamc@12 532 else
adamc@12 533 raise CUnify' CRecordFailure
adamc@12 534 | (_, []) =>
adamc@12 535 if clear2 then
adamc@12 536 List.app (fn (_, r) => r := SOME empty) unifs1
adamc@12 537 else
adamc@12 538 raise CUnify' CRecordFailure
adamc@12 539 | ((c1, _) :: rest1, (_, r2) :: rest2) =>
adamc@12 540 (r2 := SOME c1;
adamc@12 541 pairOffUnifs (rest1, rest2))
adamc@12 542 in
adamc@12 543 pairOffUnifs (unifs1, unifs2)
adamc@12 544 end
adamc@12 545
adamc@12 546 and hnormCon env (cAll as (c, _)) =
adamc@11 547 case c of
adamc@11 548 L'.CUnif (_, _, ref (SOME c)) => hnormCon env c
adamc@11 549
adamc@11 550 | L'.CNamed xn =>
adamc@11 551 (case E.lookupCNamed env xn of
adamc@11 552 (_, _, SOME c') => hnormCon env c'
adamc@11 553 | _ => cAll)
adamc@11 554
adamc@12 555 | L'.CApp (c1, c2) =>
adamc@12 556 (case hnormCon env c1 of
adamc@12 557 (L'.CAbs (_, _, cb), _) =>
adamc@12 558 ((hnormCon env (subConInCon (0, c2) cb))
adamc@12 559 handle SynUnif => cAll)
adamc@12 560 | _ => cAll)
adamc@12 561
adamc@12 562 | L'.CConcat (c1, c2) =>
adamc@12 563 (case (hnormCon env c1, hnormCon env c2) of
adamc@12 564 ((L'.CRecord (k, xcs1), loc), (L'.CRecord (_, xcs2), _)) =>
adamc@12 565 (L'.CRecord (k, xcs1 @ xcs2), loc)
adamc@12 566 | _ => cAll)
adamc@12 567
adamc@11 568 | _ => cAll
adamc@11 569
adamc@12 570 and unifyCons' env c1 c2 =
adamc@11 571 unifyCons'' env (hnormCon env c1) (hnormCon env c2)
adamc@11 572
adamc@11 573 and unifyCons'' env (c1All as (c1, _)) (c2All as (c2, _)) =
adamc@10 574 let
adamc@10 575 fun err f = raise CUnify' (f (c1All, c2All))
adamc@12 576
adamc@12 577 fun isRecord () = unifyRecordCons env (c1All, c2All)
adamc@10 578 in
adamc@10 579 case (c1, c2) of
adamc@10 580 (L'.TFun (d1, r1), L'.TFun (d2, r2)) =>
adamc@10 581 (unifyCons' env d1 d2;
adamc@10 582 unifyCons' env r1 r2)
adamc@10 583 | (L'.TCFun (expl1, x1, d1, r1), L'.TCFun (expl2, _, d2, r2)) =>
adamc@10 584 if expl1 <> expl2 then
adamc@10 585 err CExplicitness
adamc@10 586 else
adamc@10 587 (unifyKinds d1 d2;
adamc@10 588 unifyCons' (E.pushCRel env x1 d1) r1 r2)
adamc@10 589 | (L'.TRecord r1, L'.TRecord r2) => unifyCons' env r1 r2
adamc@10 590
adamc@10 591 | (L'.CRel n1, L'.CRel n2) =>
adamc@10 592 if n1 = n2 then
adamc@10 593 ()
adamc@10 594 else
adamc@10 595 err CIncompatible
adamc@10 596 | (L'.CNamed n1, L'.CNamed 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'.CApp (d1, r1), L'.CApp (d2, r2)) =>
adamc@10 603 (unifyCons' env d1 d2;
adamc@10 604 unifyCons' env r1 r2)
adamc@10 605 | (L'.CAbs (x1, k1, c1), L'.CAbs (_, k2, c2)) =>
adamc@10 606 (unifyKinds k1 k2;
adamc@10 607 unifyCons' (E.pushCRel env x1 k1) c1 c2)
adamc@10 608
adamc@10 609 | (L'.CName n1, L'.CName n2) =>
adamc@10 610 if n1 = n2 then
adamc@10 611 ()
adamc@10 612 else
adamc@10 613 err CIncompatible
adamc@10 614
adamc@10 615 | (L'.CError, _) => ()
adamc@10 616 | (_, L'.CError) => ()
adamc@10 617
adamc@10 618 | (L'.CUnif (_, _, ref (SOME c1All)), _) => unifyCons' env c1All c2All
adamc@10 619 | (_, L'.CUnif (_, _, ref (SOME c2All))) => unifyCons' env c1All c2All
adamc@10 620
adamc@10 621 | (L'.CUnif (k1, _, r1), L'.CUnif (k2, _, r2)) =>
adamc@10 622 if r1 = r2 then
adamc@10 623 ()
adamc@10 624 else
adamc@10 625 (unifyKinds k1 k2;
adamc@10 626 r1 := SOME c2All)
adamc@10 627
adamc@10 628 | (L'.CUnif (_, _, r), _) =>
adamc@10 629 if occursCon r c2All then
adamc@10 630 err COccursCheckFailed
adamc@10 631 else
adamc@10 632 r := SOME c2All
adamc@10 633 | (_, L'.CUnif (_, _, r)) =>
adamc@10 634 if occursCon r c1All then
adamc@10 635 err COccursCheckFailed
adamc@10 636 else
adamc@10 637 r := SOME c1All
adamc@10 638
adamc@12 639 | (L'.CRecord _, _) => isRecord ()
adamc@12 640 | (_, L'.CRecord _) => isRecord ()
adamc@12 641 | (L'.CConcat _, _) => isRecord ()
adamc@12 642 | (_, L'.CConcat _) => isRecord ()
adamc@12 643
adamc@10 644 | _ => err CIncompatible
adamc@10 645 end
adamc@10 646
adamc@12 647 and unifyCons env c1 c2 =
adamc@10 648 unifyCons' env c1 c2
adamc@10 649 handle CUnify' err => raise CUnify (c1, c2, err)
adamc@10 650 | KUnify args => raise CUnify (c1, c2, CKind args)
adamc@10 651
adamc@10 652 datatype exp_error =
adamc@10 653 UnboundExp of ErrorMsg.span * string
adamc@10 654 | Unify of L'.exp * L'.con * L'.con * cunify_error
adamc@11 655 | Unif of string * L'.con
adamc@11 656 | WrongForm of string * L'.exp * L'.con
adamc@10 657
adamc@10 658 fun expError env err =
adamc@10 659 case err of
adamc@10 660 UnboundExp (loc, s) =>
adamc@10 661 ErrorMsg.errorAt loc ("Unbound expression variable " ^ s)
adamc@10 662 | Unify (e, c1, c2, uerr) =>
adamc@10 663 (ErrorMsg.errorAt (#2 e) "Unification failure";
adamc@10 664 eprefaces' [("Expression", p_exp env e),
adamc@10 665 ("Have con", p_con env c1),
adamc@10 666 ("Need con", p_con env c2)];
adamc@10 667 cunifyError env uerr)
adamc@11 668 | Unif (action, c) =>
adamc@11 669 (ErrorMsg.errorAt (#2 c) ("Unification variable blocks " ^ action);
adamc@11 670 eprefaces' [("Con", p_con env c)])
adamc@11 671 | WrongForm (variety, e, t) =>
adamc@11 672 (ErrorMsg.errorAt (#2 e) ("Expression is not a " ^ variety);
adamc@11 673 eprefaces' [("Expression", p_exp env e),
adamc@11 674 ("Type", p_con env t)])
adamc@10 675
adamc@10 676 fun checkCon env e c1 c2 =
adamc@10 677 unifyCons env c1 c2
adamc@10 678 handle CUnify (c1, c2, err) =>
adamc@10 679 expError env (Unify (e, c1, c2, err))
adamc@10 680
adamc@10 681 fun elabExp env (e, loc) =
adamc@10 682 case e of
adamc@10 683 L.EAnnot (e, t) =>
adamc@10 684 let
adamc@10 685 val (e', et) = elabExp env e
adamc@10 686 val (t', _) = elabCon env t
adamc@10 687 in
adamc@10 688 checkCon env e' et t';
adamc@10 689 (e', t')
adamc@10 690 end
adamc@10 691
adamc@10 692 | L.EVar s =>
adamc@10 693 (case E.lookupE env s of
adamc@10 694 E.NotBound =>
adamc@10 695 (expError env (UnboundExp (loc, s));
adamc@10 696 (eerror, cerror))
adamc@10 697 | E.Rel (n, t) => ((L'.ERel n, loc), t)
adamc@10 698 | E.Named (n, t) => ((L'.ENamed n, loc), t))
adamc@10 699 | L.EApp (e1, e2) =>
adamc@10 700 let
adamc@10 701 val (e1', t1) = elabExp env e1
adamc@10 702 val (e2', t2) = elabExp env e2
adamc@10 703
adamc@10 704 val dom = cunif ktype
adamc@10 705 val ran = cunif ktype
adamc@10 706 val t = (L'.TFun (dom, ran), dummy)
adamc@10 707 in
adamc@10 708 checkCon env e1' t1 t;
adamc@10 709 checkCon env e2' t2 dom;
adamc@10 710 ((L'.EApp (e1', e2'), loc), ran)
adamc@10 711 end
adamc@10 712 | L.EAbs (x, to, e) =>
adamc@10 713 let
adamc@10 714 val t' = case to of
adamc@10 715 NONE => cunif ktype
adamc@10 716 | SOME t =>
adamc@10 717 let
adamc@10 718 val (t', tk) = elabCon env t
adamc@10 719 in
adamc@10 720 checkKind env t' tk ktype;
adamc@10 721 t'
adamc@10 722 end
adamc@10 723 val (e', et) = elabExp (E.pushERel env x t') e
adamc@10 724 in
adamc@10 725 ((L'.EAbs (x, t', e'), loc),
adamc@10 726 (L'.TFun (t', et), loc))
adamc@10 727 end
adamc@10 728 | L.ECApp (e, c) =>
adamc@10 729 let
adamc@10 730 val (e', et) = elabExp env e
adamc@10 731 val (c', ck) = elabCon env c
adamc@10 732 in
adamc@11 733 case #1 (hnormCon env et) of
adamc@11 734 L'.CError => (eerror, cerror)
adamc@11 735 | L'.TCFun (_, _, k, eb) =>
adamc@11 736 let
adamc@11 737 val () = checkKind env c' ck k
adamc@11 738 val eb' = subConInCon (0, c') eb
adamc@11 739 handle SynUnif => (expError env (Unif ("substitution", eb));
adamc@11 740 cerror)
adamc@11 741 in
adamc@11 742 ((L'.ECApp (e', c'), loc), eb')
adamc@11 743 end
adamc@11 744
adamc@11 745 | L'.CUnif _ =>
adamc@11 746 (expError env (Unif ("application", et));
adamc@11 747 (eerror, cerror))
adamc@11 748
adamc@11 749 | _ =>
adamc@11 750 (expError env (WrongForm ("constructor function", e', et));
adamc@11 751 (eerror, cerror))
adamc@10 752 end
adamc@11 753 | L.ECAbs (expl, x, k, e) =>
adamc@11 754 let
adamc@11 755 val expl' = elabExplicitness expl
adamc@11 756 val k' = elabKind k
adamc@11 757 val (e', et) = elabExp (E.pushCRel env x k') e
adamc@11 758 in
adamc@11 759 ((L'.ECAbs (expl', x, k', e'), loc),
adamc@11 760 (L'.TCFun (expl', x, k', et), loc))
adamc@11 761 end
adamc@6 762
adamc@12 763 | L.ERecord xes =>
adamc@12 764 let
adamc@12 765 val xes' = map (fn (x, e) =>
adamc@12 766 let
adamc@12 767 val (x', xk) = elabCon env x
adamc@12 768 val (e', et) = elabExp env e
adamc@12 769 in
adamc@12 770 checkKind env x' xk kname;
adamc@12 771 (x', e', et)
adamc@12 772 end) xes
adamc@12 773 in
adamc@12 774 ((L'.ERecord (map (fn (x', e', _) => (x', e')) xes'), loc),
adamc@12 775 (L'.TRecord (L'.CRecord (ktype, map (fn (x', _, et) => (x', et)) xes'), loc), loc))
adamc@12 776 end
adamc@12 777
adamc@12 778 | L.EField (e, c) =>
adamc@12 779 let
adamc@12 780 val (e', et) = elabExp env e
adamc@12 781 val (c', ck) = elabCon env c
adamc@12 782
adamc@12 783 val ft = cunif ktype
adamc@12 784 val rest = cunif ktype_record
adamc@12 785 in
adamc@12 786 checkKind env c' ck kname;
adamc@12 787 checkCon env e' et (L'.TRecord (L'.CConcat ((L'.CRecord (ktype, [(c', ft)]), loc), rest), loc), loc);
adamc@12 788 ((L'.EField (e', c', {field = ft, rest = rest}), loc), ft)
adamc@12 789 end
adamc@12 790
adamc@12 791
adamc@6 792 datatype decl_error =
adamc@6 793 KunifsRemainKind of ErrorMsg.span * L'.kind
adamc@6 794 | KunifsRemainCon of ErrorMsg.span * L'.con
adamc@10 795 | KunifsRemainExp of ErrorMsg.span * L'.exp
adamc@10 796 | CunifsRemainCon of ErrorMsg.span * L'.con
adamc@10 797 | CunifsRemainExp of ErrorMsg.span * L'.exp
adamc@6 798
adamc@6 799 fun declError env err =
adamc@6 800 case err of
adamc@6 801 KunifsRemainKind (loc, k) =>
adamc@6 802 (ErrorMsg.errorAt loc "Some kind unification variables are undetermined in kind";
adamc@6 803 eprefaces' [("Kind", p_kind k)])
adamc@6 804 | KunifsRemainCon (loc, c) =>
adamc@6 805 (ErrorMsg.errorAt loc "Some kind unification variables are undetermined in constructor";
adamc@6 806 eprefaces' [("Constructor", p_con env c)])
adamc@10 807 | KunifsRemainExp (loc, e) =>
adamc@10 808 (ErrorMsg.errorAt loc "Some kind unification variables are undetermined in expression";
adamc@10 809 eprefaces' [("Expression", p_exp env e)])
adamc@10 810 | CunifsRemainCon (loc, c) =>
adamc@10 811 (ErrorMsg.errorAt loc "Some constructor unification variables are undetermined in constructor";
adamc@10 812 eprefaces' [("Constructor", p_con env c)])
adamc@10 813 | CunifsRemainExp (loc, e) =>
adamc@10 814 (ErrorMsg.errorAt loc "Some constructor unification variables are undetermined in expression";
adamc@10 815 eprefaces' [("Expression", p_exp env e)])
adamc@6 816
adamc@3 817 fun elabDecl env (d, loc) =
adamc@5 818 (resetKunif ();
adamc@12 819 resetCunif ();
adamc@5 820 case d of
adamc@5 821 L.DCon (x, ko, c) =>
adamc@5 822 let
adamc@5 823 val k' = case ko of
adamc@5 824 NONE => kunif ()
adamc@5 825 | SOME k => elabKind k
adamc@3 826
adamc@5 827 val (c', ck) = elabCon env c
adamc@11 828 val (env', n) = E.pushCNamed env x k' (SOME c')
adamc@5 829 in
adamc@5 830 checkKind env c' ck k';
adamc@6 831
adamc@6 832 if kunifsInKind k' then
adamc@6 833 declError env (KunifsRemainKind (loc, k'))
adamc@6 834 else
adamc@6 835 ();
adamc@6 836
adamc@6 837 if kunifsInCon c' then
adamc@6 838 declError env (KunifsRemainCon (loc, c'))
adamc@6 839 else
adamc@6 840 ();
adamc@6 841
adamc@5 842 (env',
adamc@5 843 (L'.DCon (x, n, k', c'), loc))
adamc@10 844 end
adamc@10 845 | L.DVal (x, co, e) =>
adamc@10 846 let
adamc@10 847 val (c', ck) = case co of
adamc@10 848 NONE => (cunif ktype, ktype)
adamc@10 849 | SOME c => elabCon env c
adamc@10 850
adamc@10 851 val (e', et) = elabExp env e
adamc@10 852 val (env', n) = E.pushENamed env x c'
adamc@10 853 in
adamc@10 854 checkCon env e' et c';
adamc@10 855
adamc@10 856 if kunifsInCon c' then
adamc@10 857 declError env (KunifsRemainCon (loc, c'))
adamc@10 858 else
adamc@10 859 ();
adamc@10 860
adamc@10 861 if cunifsInCon c' then
adamc@10 862 declError env (CunifsRemainCon (loc, c'))
adamc@10 863 else
adamc@10 864 ();
adamc@10 865
adamc@10 866 if kunifsInExp e' then
adamc@10 867 declError env (KunifsRemainExp (loc, e'))
adamc@10 868 else
adamc@10 869 ();
adamc@10 870
adamc@10 871 if cunifsInExp e' then
adamc@10 872 declError env (CunifsRemainExp (loc, e'))
adamc@10 873 else
adamc@10 874 ();
adamc@10 875
adamc@10 876 (env',
adamc@10 877 (L'.DVal (x, n, c', e'), loc))
adamc@5 878 end)
adamc@3 879
adamc@5 880 fun elabFile env ds =
adamc@5 881 ListUtil.mapfoldl (fn (d, env) => elabDecl env d) env ds
adamc@2 882
adamc@2 883 end