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annotate src/elaborate.sml @ 15:1e645beb3f3b

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Implicit constructor arguments
author Adam Chlipala <adamc@hcoop.net>
date Sun, 08 Jun 2008 13:00:12 -0400
parents f1c36df29ed7
children 9bd8669d53c2
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@14 30 structure P = Prim
adamc@4 31 structure L = Source
adamc@2 32 structure L' = Elab
adamc@2 33 structure E = ElabEnv
adamc@2 34 structure U = ElabUtil
adamc@2 35
adamc@3 36 open Print
adamc@3 37 open ElabPrint
adamc@3 38
adamc@2 39 fun elabKind (k, loc) =
adamc@2 40 case k of
adamc@2 41 L.KType => (L'.KType, loc)
adamc@2 42 | L.KArrow (k1, k2) => (L'.KArrow (elabKind k1, elabKind k2), loc)
adamc@2 43 | L.KName => (L'.KName, loc)
adamc@2 44 | L.KRecord k => (L'.KRecord (elabKind k), loc)
adamc@2 45
adamc@2 46 fun elabExplicitness e =
adamc@2 47 case e of
adamc@2 48 L.Explicit => L'.Explicit
adamc@2 49 | L.Implicit => L'.Implicit
adamc@2 50
adamc@2 51 fun occursKind r =
adamc@2 52 U.Kind.exists (fn L'.KUnif (_, r') => r = r'
adamc@2 53 | _ => false)
adamc@2 54
adamc@3 55 datatype kunify_error =
adamc@2 56 KOccursCheckFailed of L'.kind * L'.kind
adamc@2 57 | KIncompatible of L'.kind * L'.kind
adamc@2 58
adamc@3 59 exception KUnify' of kunify_error
adamc@3 60
adamc@3 61 fun kunifyError err =
adamc@2 62 case err of
adamc@2 63 KOccursCheckFailed (k1, k2) =>
adamc@3 64 eprefaces "Kind occurs check failed"
adamc@3 65 [("Kind 1", p_kind k1),
adamc@3 66 ("Kind 2", p_kind k2)]
adamc@2 67 | KIncompatible (k1, k2) =>
adamc@3 68 eprefaces "Incompatible kinds"
adamc@3 69 [("Kind 1", p_kind k1),
adamc@3 70 ("Kind 2", p_kind k2)]
adamc@2 71
adamc@3 72 fun unifyKinds' (k1All as (k1, _)) (k2All as (k2, _)) =
adamc@2 73 let
adamc@3 74 fun err f = raise KUnify' (f (k1All, k2All))
adamc@2 75 in
adamc@2 76 case (k1, k2) of
adamc@2 77 (L'.KType, L'.KType) => ()
adamc@2 78 | (L'.KArrow (d1, r1), L'.KArrow (d2, r2)) =>
adamc@3 79 (unifyKinds' d1 d2;
adamc@3 80 unifyKinds' r1 r2)
adamc@2 81 | (L'.KName, L'.KName) => ()
adamc@3 82 | (L'.KRecord k1, L'.KRecord k2) => unifyKinds' k1 k2
adamc@2 83
adamc@2 84 | (L'.KError, _) => ()
adamc@2 85 | (_, L'.KError) => ()
adamc@2 86
adamc@3 87 | (L'.KUnif (_, ref (SOME k1All)), _) => unifyKinds' k1All k2All
adamc@3 88 | (_, L'.KUnif (_, ref (SOME k2All))) => unifyKinds' k1All k2All
adamc@2 89
adamc@2 90 | (L'.KUnif (_, r1), L'.KUnif (_, r2)) =>
adamc@2 91 if r1 = r2 then
adamc@2 92 ()
adamc@2 93 else
adamc@2 94 r1 := SOME k2All
adamc@2 95
adamc@2 96 | (L'.KUnif (_, r), _) =>
adamc@2 97 if occursKind r k2All then
adamc@2 98 err KOccursCheckFailed
adamc@2 99 else
adamc@2 100 r := SOME k2All
adamc@2 101 | (_, L'.KUnif (_, r)) =>
adamc@2 102 if occursKind r k1All then
adamc@2 103 err KOccursCheckFailed
adamc@2 104 else
adamc@2 105 r := SOME k1All
adamc@2 106
adamc@2 107 | _ => err KIncompatible
adamc@2 108 end
adamc@2 109
adamc@3 110 exception KUnify of L'.kind * L'.kind * kunify_error
adamc@3 111
adamc@3 112 fun unifyKinds k1 k2 =
adamc@3 113 unifyKinds' k1 k2
adamc@3 114 handle KUnify' err => raise KUnify (k1, k2, err)
adamc@3 115
adamc@3 116 datatype con_error =
adamc@3 117 UnboundCon of ErrorMsg.span * string
adamc@3 118 | WrongKind of L'.con * L'.kind * L'.kind * kunify_error
adamc@3 119
adamc@5 120 fun conError env err =
adamc@3 121 case err of
adamc@3 122 UnboundCon (loc, s) =>
adamc@3 123 ErrorMsg.errorAt loc ("Unbound constructor variable " ^ s)
adamc@3 124 | WrongKind (c, k1, k2, kerr) =>
adamc@3 125 (ErrorMsg.errorAt (#2 c) "Wrong kind";
adamc@5 126 eprefaces' [("Constructor", p_con env c),
adamc@5 127 ("Have kind", p_kind k1),
adamc@5 128 ("Need kind", p_kind k2)];
adamc@3 129 kunifyError kerr)
adamc@3 130
adamc@5 131 fun checkKind env c k1 k2 =
adamc@3 132 unifyKinds k1 k2
adamc@3 133 handle KUnify (k1, k2, err) =>
adamc@5 134 conError env (WrongKind (c, k1, k2, err))
adamc@3 135
adamc@3 136 val dummy = ErrorMsg.dummySpan
adamc@3 137
adamc@3 138 val ktype = (L'.KType, dummy)
adamc@3 139 val kname = (L'.KName, dummy)
adamc@12 140 val ktype_record = (L'.KRecord ktype, dummy)
adamc@3 141
adamc@3 142 val cerror = (L'.CError, dummy)
adamc@3 143 val kerror = (L'.KError, dummy)
adamc@10 144 val eerror = (L'.EError, dummy)
adamc@3 145
adamc@3 146 local
adamc@3 147 val count = ref 0
adamc@3 148 in
adamc@3 149
adamc@3 150 fun resetKunif () = count := 0
adamc@3 151
adamc@3 152 fun kunif () =
adamc@3 153 let
adamc@3 154 val n = !count
adamc@3 155 val s = if n <= 26 then
adamc@3 156 str (chr (ord #"A" + n))
adamc@3 157 else
adamc@3 158 "U" ^ Int.toString (n - 26)
adamc@3 159 in
adamc@3 160 count := n + 1;
adamc@3 161 (L'.KUnif (s, ref NONE), dummy)
adamc@3 162 end
adamc@3 163
adamc@3 164 end
adamc@3 165
adamc@10 166 local
adamc@10 167 val count = ref 0
adamc@10 168 in
adamc@10 169
adamc@10 170 fun resetCunif () = count := 0
adamc@10 171
adamc@10 172 fun cunif k =
adamc@10 173 let
adamc@10 174 val n = !count
adamc@10 175 val s = if n <= 26 then
adamc@10 176 str (chr (ord #"A" + n))
adamc@10 177 else
adamc@10 178 "U" ^ Int.toString (n - 26)
adamc@10 179 in
adamc@10 180 count := n + 1;
adamc@10 181 (L'.CUnif (k, s, ref NONE), dummy)
adamc@10 182 end
adamc@10 183
adamc@10 184 end
adamc@10 185
adamc@3 186 fun elabCon env (c, loc) =
adamc@3 187 case c of
adamc@3 188 L.CAnnot (c, k) =>
adamc@3 189 let
adamc@3 190 val k' = elabKind k
adamc@3 191 val (c', ck) = elabCon env c
adamc@3 192 in
adamc@5 193 checkKind env c' ck k';
adamc@3 194 (c', k')
adamc@3 195 end
adamc@3 196
adamc@3 197 | L.TFun (t1, t2) =>
adamc@3 198 let
adamc@3 199 val (t1', k1) = elabCon env t1
adamc@3 200 val (t2', k2) = elabCon env t2
adamc@3 201 in
adamc@5 202 checkKind env t1' k1 ktype;
adamc@5 203 checkKind env t2' k2 ktype;
adamc@3 204 ((L'.TFun (t1', t2'), loc), ktype)
adamc@3 205 end
adamc@3 206 | L.TCFun (e, x, k, t) =>
adamc@3 207 let
adamc@3 208 val e' = elabExplicitness e
adamc@3 209 val k' = elabKind k
adamc@3 210 val env' = E.pushCRel env x k'
adamc@3 211 val (t', tk) = elabCon env' t
adamc@3 212 in
adamc@5 213 checkKind env t' tk ktype;
adamc@3 214 ((L'.TCFun (e', x, k', t'), loc), ktype)
adamc@3 215 end
adamc@3 216 | L.TRecord c =>
adamc@3 217 let
adamc@3 218 val (c', ck) = elabCon env c
adamc@3 219 val k = (L'.KRecord ktype, loc)
adamc@3 220 in
adamc@5 221 checkKind env c' ck k;
adamc@3 222 ((L'.TRecord c', loc), ktype)
adamc@3 223 end
adamc@3 224
adamc@3 225 | L.CVar s =>
adamc@3 226 (case E.lookupC env s of
adamc@9 227 E.NotBound =>
adamc@5 228 (conError env (UnboundCon (loc, s));
adamc@3 229 (cerror, kerror))
adamc@9 230 | E.Rel (n, k) =>
adamc@3 231 ((L'.CRel n, loc), k)
adamc@9 232 | E.Named (n, k) =>
adamc@3 233 ((L'.CNamed n, loc), k))
adamc@3 234 | L.CApp (c1, c2) =>
adamc@3 235 let
adamc@3 236 val (c1', k1) = elabCon env c1
adamc@3 237 val (c2', k2) = elabCon env c2
adamc@3 238 val dom = kunif ()
adamc@3 239 val ran = kunif ()
adamc@3 240 in
adamc@5 241 checkKind env c1' k1 (L'.KArrow (dom, ran), loc);
adamc@5 242 checkKind env c2' k2 dom;
adamc@3 243 ((L'.CApp (c1', c2'), loc), ran)
adamc@3 244 end
adamc@8 245 | L.CAbs (x, k, t) =>
adamc@3 246 let
adamc@3 247 val k' = elabKind k
adamc@3 248 val env' = E.pushCRel env x k'
adamc@3 249 val (t', tk) = elabCon env' t
adamc@3 250 in
adamc@8 251 ((L'.CAbs (x, k', t'), loc),
adamc@3 252 (L'.KArrow (k', tk), loc))
adamc@3 253 end
adamc@3 254
adamc@3 255 | L.CName s =>
adamc@3 256 ((L'.CName s, loc), kname)
adamc@3 257
adamc@3 258 | L.CRecord xcs =>
adamc@3 259 let
adamc@3 260 val k = kunif ()
adamc@3 261
adamc@3 262 val xcs' = map (fn (x, c) =>
adamc@3 263 let
adamc@3 264 val (x', xk) = elabCon env x
adamc@3 265 val (c', ck) = elabCon env c
adamc@3 266 in
adamc@5 267 checkKind env x' xk kname;
adamc@5 268 checkKind env c' ck k;
adamc@3 269 (x', c')
adamc@3 270 end) xcs
adamc@3 271 in
adamc@5 272 ((L'.CRecord (k, xcs'), loc), (L'.KRecord k, loc))
adamc@3 273 end
adamc@3 274 | L.CConcat (c1, c2) =>
adamc@3 275 let
adamc@3 276 val (c1', k1) = elabCon env c1
adamc@3 277 val (c2', k2) = elabCon env c2
adamc@3 278 val ku = kunif ()
adamc@3 279 val k = (L'.KRecord ku, loc)
adamc@3 280 in
adamc@5 281 checkKind env c1' k1 k;
adamc@5 282 checkKind env c2' k2 k;
adamc@3 283 ((L'.CConcat (c1', c2'), loc), k)
adamc@3 284 end
adamc@3 285
adamc@6 286 fun kunifsRemain k =
adamc@6 287 case k of
adamc@6 288 L'.KUnif (_, ref NONE) => true
adamc@6 289 | _ => false
adamc@10 290 fun cunifsRemain c =
adamc@10 291 case c of
adamc@10 292 L'.CUnif (_, _, ref NONE) => true
adamc@10 293 | _ => false
adamc@6 294
adamc@6 295 val kunifsInKind = U.Kind.exists kunifsRemain
adamc@6 296 val kunifsInCon = U.Con.exists {kind = kunifsRemain,
adamc@6 297 con = fn _ => false}
adamc@10 298 val kunifsInExp = U.Exp.exists {kind = kunifsRemain,
adamc@10 299 con = fn _ => false,
adamc@10 300 exp = fn _ => false}
adamc@10 301
adamc@10 302 val cunifsInCon = U.Con.exists {kind = fn _ => false,
adamc@10 303 con = cunifsRemain}
adamc@10 304 val cunifsInExp = U.Exp.exists {kind = fn _ => false,
adamc@10 305 con = cunifsRemain,
adamc@10 306 exp = fn _ => false}
adamc@10 307
adamc@10 308 fun occursCon r =
adamc@10 309 U.Con.exists {kind = fn _ => false,
adamc@10 310 con = fn L'.CUnif (_, _, r') => r = r'
adamc@10 311 | _ => false}
adamc@10 312
adamc@10 313 datatype cunify_error =
adamc@10 314 CKind of L'.kind * L'.kind * kunify_error
adamc@10 315 | COccursCheckFailed of L'.con * L'.con
adamc@10 316 | CIncompatible of L'.con * L'.con
adamc@10 317 | CExplicitness of L'.con * L'.con
adamc@12 318 | CKindof of L'.con
adamc@12 319 | CRecordFailure
adamc@10 320
adamc@10 321 exception CUnify' of cunify_error
adamc@10 322
adamc@10 323 fun cunifyError env err =
adamc@10 324 case err of
adamc@10 325 CKind (k1, k2, kerr) =>
adamc@10 326 (eprefaces "Kind unification failure"
adamc@10 327 [("Kind 1", p_kind k1),
adamc@10 328 ("Kind 2", p_kind k2)];
adamc@10 329 kunifyError kerr)
adamc@10 330 | COccursCheckFailed (c1, c2) =>
adamc@10 331 eprefaces "Constructor occurs check failed"
adamc@10 332 [("Con 1", p_con env c1),
adamc@10 333 ("Con 2", p_con env c2)]
adamc@10 334 | CIncompatible (c1, c2) =>
adamc@10 335 eprefaces "Incompatible constructors"
adamc@10 336 [("Con 1", p_con env c1),
adamc@10 337 ("Con 2", p_con env c2)]
adamc@10 338 | CExplicitness (c1, c2) =>
adamc@10 339 eprefaces "Differing constructor function explicitness"
adamc@10 340 [("Con 1", p_con env c1),
adamc@10 341 ("Con 2", p_con env c2)]
adamc@12 342 | CKindof c =>
adamc@12 343 eprefaces "Kind unification variable blocks kindof calculation"
adamc@12 344 [("Con", p_con env c)]
adamc@12 345 | CRecordFailure =>
adamc@12 346 eprefaces "Can't unify record constructors" []
adamc@10 347
adamc@13 348 exception SynUnif = E.SynUnif
adamc@13 349 val liftConInCon = E.liftConInCon
adamc@12 350
adamc@12 351 val subConInCon =
adamc@12 352 U.Con.mapB {kind = fn k => k,
adamc@12 353 con = fn (xn, rep) => fn c =>
adamc@12 354 case c of
adamc@12 355 L'.CRel xn' =>
adamc@12 356 if xn = xn' then
adamc@12 357 #1 rep
adamc@12 358 else
adamc@12 359 c
adamc@12 360 | L'.CUnif _ => raise SynUnif
adamc@12 361 | _ => c,
adamc@12 362 bind = fn ((xn, rep), U.Con.Rel _) => (xn+1, liftConInCon 0 rep)
adamc@12 363 | (ctx, _) => ctx}
adamc@12 364
adamc@12 365 type record_summary = {
adamc@12 366 fields : (L'.con * L'.con) list,
adamc@12 367 unifs : (L'.con * L'.con option ref) list,
adamc@12 368 others : L'.con list
adamc@12 369 }
adamc@12 370
adamc@12 371 fun summaryToCon {fields, unifs, others} =
adamc@12 372 let
adamc@12 373 val c = (L'.CRecord (ktype, []), dummy)
adamc@12 374 val c = List.foldr (fn (c', c) => (L'.CConcat (c', c), dummy)) c others
adamc@12 375 val c = List.foldr (fn ((c', _), c) => (L'.CConcat (c', c), dummy)) c unifs
adamc@12 376 in
adamc@12 377 (L'.CConcat ((L'.CRecord (ktype, fields), dummy), c), dummy)
adamc@12 378 end
adamc@12 379
adamc@12 380 fun p_summary env s = p_con env (summaryToCon s)
adamc@12 381
adamc@12 382 exception CUnify of L'.con * L'.con * cunify_error
adamc@12 383
adamc@12 384 fun hnormKind (kAll as (k, _)) =
adamc@12 385 case k of
adamc@12 386 L'.KUnif (_, ref (SOME k)) => hnormKind k
adamc@12 387 | _ => kAll
adamc@12 388
adamc@12 389 fun kindof env (c, loc) =
adamc@12 390 case c of
adamc@12 391 L'.TFun _ => ktype
adamc@12 392 | L'.TCFun _ => ktype
adamc@12 393 | L'.TRecord _ => ktype
adamc@12 394
adamc@12 395 | L'.CRel xn => #2 (E.lookupCRel env xn)
adamc@12 396 | L'.CNamed xn => #2 (E.lookupCNamed env xn)
adamc@12 397 | L'.CApp (c, _) =>
adamc@12 398 (case #1 (hnormKind (kindof env c)) of
adamc@12 399 L'.KArrow (_, k) => k
adamc@12 400 | L'.KError => kerror
adamc@12 401 | _ => raise CUnify' (CKindof c))
adamc@12 402 | L'.CAbs (x, k, c) => (L'.KArrow (k, kindof (E.pushCRel env x k) c), loc)
adamc@12 403
adamc@12 404 | L'.CName _ => kname
adamc@12 405
adamc@12 406 | L'.CRecord (k, _) => (L'.KRecord k, loc)
adamc@12 407 | L'.CConcat (c, _) => kindof env c
adamc@12 408
adamc@12 409 | L'.CError => kerror
adamc@12 410 | L'.CUnif (k, _, _) => k
adamc@12 411
adamc@12 412 fun unifyRecordCons env (c1, c2) =
adamc@12 413 let
adamc@12 414 val k1 = kindof env c1
adamc@12 415 val k2 = kindof env c2
adamc@12 416 in
adamc@12 417 unifyKinds k1 k2;
adamc@12 418 unifySummaries env (k1, recordSummary env c1, recordSummary env c2)
adamc@12 419 end
adamc@12 420
adamc@12 421 and recordSummary env c : record_summary =
adamc@12 422 case hnormCon env c of
adamc@12 423 (L'.CRecord (_, xcs), _) => {fields = xcs, unifs = [], others = []}
adamc@12 424 | (L'.CConcat (c1, c2), _) =>
adamc@12 425 let
adamc@12 426 val s1 = recordSummary env c1
adamc@12 427 val s2 = recordSummary env c2
adamc@12 428 in
adamc@12 429 {fields = #fields s1 @ #fields s2,
adamc@12 430 unifs = #unifs s1 @ #unifs s2,
adamc@12 431 others = #others s1 @ #others s2}
adamc@12 432 end
adamc@12 433 | (L'.CUnif (_, _, ref (SOME c)), _) => recordSummary env c
adamc@12 434 | c' as (L'.CUnif (_, _, r), _) => {fields = [], unifs = [(c', r)], others = []}
adamc@12 435 | c' => {fields = [], unifs = [], others = [c']}
adamc@12 436
adamc@12 437 and consEq env (c1, c2) =
adamc@12 438 (unifyCons env c1 c2;
adamc@12 439 true)
adamc@12 440 handle CUnify _ => false
adamc@12 441
adamc@12 442 and unifySummaries env (k, s1 : record_summary, s2 : record_summary) =
adamc@12 443 let
adamc@14 444 (*val () = eprefaces "Summaries" [("#1", p_summary env s1),
adamc@14 445 ("#2", p_summary env s2)]*)
adamc@12 446
adamc@12 447 fun eatMatching p (ls1, ls2) =
adamc@12 448 let
adamc@12 449 fun em (ls1, ls2, passed1) =
adamc@12 450 case ls1 of
adamc@12 451 [] => (rev passed1, ls2)
adamc@12 452 | h1 :: t1 =>
adamc@12 453 let
adamc@12 454 fun search (ls2', passed2) =
adamc@12 455 case ls2' of
adamc@12 456 [] => em (t1, ls2, h1 :: passed1)
adamc@12 457 | h2 :: t2 =>
adamc@12 458 if p (h1, h2) then
adamc@12 459 em (t1, List.revAppend (passed2, t2), passed1)
adamc@12 460 else
adamc@12 461 search (t2, h2 :: passed2)
adamc@12 462 in
adamc@12 463 search (ls2, [])
adamc@12 464 end
adamc@12 465 in
adamc@12 466 em (ls1, ls2, [])
adamc@12 467 end
adamc@12 468
adamc@12 469 val (fs1, fs2) = eatMatching (fn ((x1, c1), (x2, c2)) =>
adamc@12 470 if consEq env (x1, x2) then
adamc@12 471 (unifyCons env c1 c2;
adamc@12 472 true)
adamc@12 473 else
adamc@12 474 false) (#fields s1, #fields s2)
adamc@14 475 (*val () = eprefaces "Summaries2" [("#1", p_summary env {fields = fs1, unifs = #unifs s1, others = #others s1}),
adamc@14 476 ("#2", p_summary env {fields = fs2, unifs = #unifs s2, others = #others s2})]*)
adamc@12 477 val (unifs1, unifs2) = eatMatching (fn ((_, r1), (_, r2)) => r1 = r2) (#unifs s1, #unifs s2)
adamc@12 478 val (others1, others2) = eatMatching (consEq env) (#others s1, #others s2)
adamc@12 479
adamc@12 480 fun unifFields (fs, others, unifs) =
adamc@12 481 case (fs, others, unifs) of
adamc@12 482 ([], [], _) => ([], [], unifs)
adamc@12 483 | (_, _, []) => (fs, others, [])
adamc@12 484 | (_, _, (_, r) :: rest) =>
adamc@12 485 let
adamc@12 486 val r' = ref NONE
adamc@12 487 val cr' = (L'.CUnif (k, "recd", r'), dummy)
adamc@12 488
adamc@12 489 val prefix = case (fs, others) of
adamc@12 490 ([], other :: others) =>
adamc@12 491 List.foldl (fn (other, c) =>
adamc@12 492 (L'.CConcat (c, other), dummy))
adamc@12 493 other others
adamc@12 494 | (fs, []) =>
adamc@12 495 (L'.CRecord (k, fs), dummy)
adamc@12 496 | (fs, others) =>
adamc@12 497 List.foldl (fn (other, c) =>
adamc@12 498 (L'.CConcat (c, other), dummy))
adamc@12 499 (L'.CRecord (k, fs), dummy) others
adamc@12 500 in
adamc@12 501 r := SOME (L'.CConcat (prefix, cr'), dummy);
adamc@12 502 ([], [], (cr', r') :: rest)
adamc@12 503 end
adamc@12 504
adamc@12 505 val (fs1, others1, unifs2) = unifFields (fs1, others1, unifs2)
adamc@12 506 val (fs2, others2, unifs1) = unifFields (fs2, others2, unifs1)
adamc@12 507
adamc@12 508 val clear1 = case (fs1, others1) of
adamc@12 509 ([], []) => true
adamc@12 510 | _ => false
adamc@12 511 val clear2 = case (fs2, others2) of
adamc@12 512 ([], []) => true
adamc@12 513 | _ => false
adamc@12 514 val empty = (L'.CRecord (k, []), dummy)
adamc@12 515 fun pairOffUnifs (unifs1, unifs2) =
adamc@12 516 case (unifs1, unifs2) of
adamc@12 517 ([], _) =>
adamc@12 518 if clear1 then
adamc@12 519 List.app (fn (_, r) => r := SOME empty) unifs2
adamc@12 520 else
adamc@12 521 raise CUnify' CRecordFailure
adamc@12 522 | (_, []) =>
adamc@12 523 if clear2 then
adamc@12 524 List.app (fn (_, r) => r := SOME empty) unifs1
adamc@12 525 else
adamc@12 526 raise CUnify' CRecordFailure
adamc@12 527 | ((c1, _) :: rest1, (_, r2) :: rest2) =>
adamc@12 528 (r2 := SOME c1;
adamc@12 529 pairOffUnifs (rest1, rest2))
adamc@12 530 in
adamc@12 531 pairOffUnifs (unifs1, unifs2)
adamc@12 532 end
adamc@12 533
adamc@12 534 and hnormCon env (cAll as (c, _)) =
adamc@11 535 case c of
adamc@11 536 L'.CUnif (_, _, ref (SOME c)) => hnormCon env c
adamc@11 537
adamc@11 538 | L'.CNamed xn =>
adamc@11 539 (case E.lookupCNamed env xn of
adamc@11 540 (_, _, SOME c') => hnormCon env c'
adamc@11 541 | _ => cAll)
adamc@11 542
adamc@12 543 | L'.CApp (c1, c2) =>
adamc@12 544 (case hnormCon env c1 of
adamc@12 545 (L'.CAbs (_, _, cb), _) =>
adamc@12 546 ((hnormCon env (subConInCon (0, c2) cb))
adamc@12 547 handle SynUnif => cAll)
adamc@12 548 | _ => cAll)
adamc@12 549
adamc@12 550 | L'.CConcat (c1, c2) =>
adamc@12 551 (case (hnormCon env c1, hnormCon env c2) of
adamc@12 552 ((L'.CRecord (k, xcs1), loc), (L'.CRecord (_, xcs2), _)) =>
adamc@12 553 (L'.CRecord (k, xcs1 @ xcs2), loc)
adamc@12 554 | _ => cAll)
adamc@12 555
adamc@11 556 | _ => cAll
adamc@11 557
adamc@12 558 and unifyCons' env c1 c2 =
adamc@11 559 unifyCons'' env (hnormCon env c1) (hnormCon env c2)
adamc@11 560
adamc@11 561 and unifyCons'' env (c1All as (c1, _)) (c2All as (c2, _)) =
adamc@10 562 let
adamc@10 563 fun err f = raise CUnify' (f (c1All, c2All))
adamc@12 564
adamc@12 565 fun isRecord () = unifyRecordCons env (c1All, c2All)
adamc@10 566 in
adamc@10 567 case (c1, c2) of
adamc@10 568 (L'.TFun (d1, r1), L'.TFun (d2, r2)) =>
adamc@10 569 (unifyCons' env d1 d2;
adamc@10 570 unifyCons' env r1 r2)
adamc@10 571 | (L'.TCFun (expl1, x1, d1, r1), L'.TCFun (expl2, _, d2, r2)) =>
adamc@10 572 if expl1 <> expl2 then
adamc@10 573 err CExplicitness
adamc@10 574 else
adamc@10 575 (unifyKinds d1 d2;
adamc@10 576 unifyCons' (E.pushCRel env x1 d1) r1 r2)
adamc@10 577 | (L'.TRecord r1, L'.TRecord r2) => unifyCons' env r1 r2
adamc@10 578
adamc@10 579 | (L'.CRel n1, L'.CRel n2) =>
adamc@10 580 if n1 = n2 then
adamc@10 581 ()
adamc@10 582 else
adamc@10 583 err CIncompatible
adamc@10 584 | (L'.CNamed n1, L'.CNamed n2) =>
adamc@10 585 if n1 = n2 then
adamc@10 586 ()
adamc@10 587 else
adamc@10 588 err CIncompatible
adamc@10 589
adamc@10 590 | (L'.CApp (d1, r1), L'.CApp (d2, r2)) =>
adamc@10 591 (unifyCons' env d1 d2;
adamc@10 592 unifyCons' env r1 r2)
adamc@10 593 | (L'.CAbs (x1, k1, c1), L'.CAbs (_, k2, c2)) =>
adamc@10 594 (unifyKinds k1 k2;
adamc@10 595 unifyCons' (E.pushCRel env x1 k1) c1 c2)
adamc@10 596
adamc@10 597 | (L'.CName n1, L'.CName n2) =>
adamc@10 598 if n1 = n2 then
adamc@10 599 ()
adamc@10 600 else
adamc@10 601 err CIncompatible
adamc@10 602
adamc@10 603 | (L'.CError, _) => ()
adamc@10 604 | (_, L'.CError) => ()
adamc@10 605
adamc@10 606 | (L'.CUnif (_, _, ref (SOME c1All)), _) => unifyCons' env c1All c2All
adamc@10 607 | (_, L'.CUnif (_, _, ref (SOME c2All))) => unifyCons' env c1All c2All
adamc@10 608
adamc@10 609 | (L'.CUnif (k1, _, r1), L'.CUnif (k2, _, r2)) =>
adamc@10 610 if r1 = r2 then
adamc@10 611 ()
adamc@10 612 else
adamc@10 613 (unifyKinds k1 k2;
adamc@10 614 r1 := SOME c2All)
adamc@10 615
adamc@10 616 | (L'.CUnif (_, _, r), _) =>
adamc@10 617 if occursCon r c2All then
adamc@10 618 err COccursCheckFailed
adamc@10 619 else
adamc@10 620 r := SOME c2All
adamc@10 621 | (_, L'.CUnif (_, _, r)) =>
adamc@10 622 if occursCon r c1All then
adamc@10 623 err COccursCheckFailed
adamc@10 624 else
adamc@10 625 r := SOME c1All
adamc@10 626
adamc@12 627 | (L'.CRecord _, _) => isRecord ()
adamc@12 628 | (_, L'.CRecord _) => isRecord ()
adamc@12 629 | (L'.CConcat _, _) => isRecord ()
adamc@12 630 | (_, L'.CConcat _) => isRecord ()
adamc@12 631
adamc@10 632 | _ => err CIncompatible
adamc@10 633 end
adamc@10 634
adamc@12 635 and unifyCons env c1 c2 =
adamc@10 636 unifyCons' env c1 c2
adamc@10 637 handle CUnify' err => raise CUnify (c1, c2, err)
adamc@10 638 | KUnify args => raise CUnify (c1, c2, CKind args)
adamc@10 639
adamc@10 640 datatype exp_error =
adamc@10 641 UnboundExp of ErrorMsg.span * string
adamc@10 642 | Unify of L'.exp * L'.con * L'.con * cunify_error
adamc@11 643 | Unif of string * L'.con
adamc@11 644 | WrongForm of string * L'.exp * L'.con
adamc@10 645
adamc@10 646 fun expError env err =
adamc@10 647 case err of
adamc@10 648 UnboundExp (loc, s) =>
adamc@10 649 ErrorMsg.errorAt loc ("Unbound expression variable " ^ s)
adamc@10 650 | Unify (e, c1, c2, uerr) =>
adamc@10 651 (ErrorMsg.errorAt (#2 e) "Unification failure";
adamc@10 652 eprefaces' [("Expression", p_exp env e),
adamc@10 653 ("Have con", p_con env c1),
adamc@10 654 ("Need con", p_con env c2)];
adamc@10 655 cunifyError env uerr)
adamc@11 656 | Unif (action, c) =>
adamc@11 657 (ErrorMsg.errorAt (#2 c) ("Unification variable blocks " ^ action);
adamc@11 658 eprefaces' [("Con", p_con env c)])
adamc@11 659 | WrongForm (variety, e, t) =>
adamc@11 660 (ErrorMsg.errorAt (#2 e) ("Expression is not a " ^ variety);
adamc@11 661 eprefaces' [("Expression", p_exp env e),
adamc@11 662 ("Type", p_con env t)])
adamc@10 663
adamc@10 664 fun checkCon env e c1 c2 =
adamc@10 665 unifyCons env c1 c2
adamc@10 666 handle CUnify (c1, c2, err) =>
adamc@10 667 expError env (Unify (e, c1, c2, err))
adamc@10 668
adamc@14 669 fun primType env p =
adamc@14 670 let
adamc@14 671 val s = case p of
adamc@14 672 P.Int _ => "int"
adamc@14 673 | P.Float _ => "float"
adamc@14 674 | P.String _ => "string"
adamc@14 675 in
adamc@14 676 case E.lookupC env s of
adamc@14 677 E.NotBound => raise Fail ("Primitive type " ^ s ^ " unbound")
adamc@14 678 | E.Rel _ => raise Fail ("Primitive type " ^ s ^ " bound as relative")
adamc@14 679 | E.Named (n, (L'.KType, _)) => L'.CNamed n
adamc@14 680 | E.Named _ => raise Fail ("Primitive type " ^ s ^ " bound at non-Type kind")
adamc@14 681 end
adamc@14 682
adamc@15 683 fun typeof env (e, loc) =
adamc@15 684 case e of
adamc@15 685 L'.EPrim p => (primType env p, loc)
adamc@15 686 | L'.ERel n => #2 (E.lookupERel env n)
adamc@15 687 | L'.ENamed n => #2 (E.lookupENamed env n)
adamc@15 688 | L'.EApp (e1, _) =>
adamc@15 689 (case #1 (typeof env e1) of
adamc@15 690 L'.TFun (_, c) => c
adamc@15 691 | _ => raise Fail "typeof: Bad EApp")
adamc@15 692 | L'.EAbs (x, t, e1) => (L'.TFun (t, typeof (E.pushERel env x t) e1), loc)
adamc@15 693 | L'.ECApp (e1, c) =>
adamc@15 694 (case #1 (typeof env e1) of
adamc@15 695 L'.TCFun (_, _, _, c1) => subConInCon (0, c) c1
adamc@15 696 | _ => raise Fail "typeof: Bad ECApp")
adamc@15 697 | L'.ECAbs (expl, x, k, e1) => (L'.TCFun (expl, x, k, typeof (E.pushCRel env x k) e1), loc)
adamc@15 698
adamc@15 699 | L'.ERecord xes => (L'.TRecord (L'.CRecord (ktype, map (fn (x, e) => (x, typeof env e)) xes), loc), loc)
adamc@15 700 | L'.EField (_, _, {field, ...}) => field
adamc@15 701
adamc@15 702 | L'.EError => cerror
adamc@15 703
adamc@15 704 fun elabHead env (e as (_, loc)) t =
adamc@15 705 let
adamc@15 706 fun unravel (t, e) =
adamc@15 707 case hnormCon env t of
adamc@15 708 (L'.TCFun (L'.Implicit, x, k, t'), _) =>
adamc@15 709 let
adamc@15 710 val u = cunif k
adamc@15 711 in
adamc@15 712 unravel (subConInCon (0, u) t',
adamc@15 713 (L'.ECApp (e, u), loc))
adamc@15 714 end
adamc@15 715 | _ => (e, t)
adamc@15 716 in
adamc@15 717 unravel (t, e)
adamc@15 718 end
adamc@15 719
adamc@10 720 fun elabExp env (e, loc) =
adamc@10 721 case e of
adamc@10 722 L.EAnnot (e, t) =>
adamc@10 723 let
adamc@10 724 val (e', et) = elabExp env e
adamc@10 725 val (t', _) = elabCon env t
adamc@10 726 in
adamc@10 727 checkCon env e' et t';
adamc@10 728 (e', t')
adamc@10 729 end
adamc@10 730
adamc@14 731 | L.EPrim p => ((L'.EPrim p, loc), (primType env p, loc))
adamc@10 732 | L.EVar s =>
adamc@10 733 (case E.lookupE env s of
adamc@10 734 E.NotBound =>
adamc@10 735 (expError env (UnboundExp (loc, s));
adamc@10 736 (eerror, cerror))
adamc@10 737 | E.Rel (n, t) => ((L'.ERel n, loc), t)
adamc@10 738 | E.Named (n, t) => ((L'.ENamed n, loc), t))
adamc@10 739 | L.EApp (e1, e2) =>
adamc@10 740 let
adamc@10 741 val (e1', t1) = elabExp env e1
adamc@15 742 val (e1', t1) = elabHead env e1' t1
adamc@10 743 val (e2', t2) = elabExp env e2
adamc@10 744
adamc@10 745 val dom = cunif ktype
adamc@10 746 val ran = cunif ktype
adamc@10 747 val t = (L'.TFun (dom, ran), dummy)
adamc@10 748 in
adamc@10 749 checkCon env e1' t1 t;
adamc@10 750 checkCon env e2' t2 dom;
adamc@10 751 ((L'.EApp (e1', e2'), loc), ran)
adamc@10 752 end
adamc@10 753 | L.EAbs (x, to, e) =>
adamc@10 754 let
adamc@10 755 val t' = case to of
adamc@10 756 NONE => cunif ktype
adamc@10 757 | SOME t =>
adamc@10 758 let
adamc@10 759 val (t', tk) = elabCon env t
adamc@10 760 in
adamc@10 761 checkKind env t' tk ktype;
adamc@10 762 t'
adamc@10 763 end
adamc@10 764 val (e', et) = elabExp (E.pushERel env x t') e
adamc@10 765 in
adamc@10 766 ((L'.EAbs (x, t', e'), loc),
adamc@10 767 (L'.TFun (t', et), loc))
adamc@10 768 end
adamc@10 769 | L.ECApp (e, c) =>
adamc@10 770 let
adamc@10 771 val (e', et) = elabExp env e
adamc@15 772 val (e', et) = elabHead env e' et
adamc@10 773 val (c', ck) = elabCon env c
adamc@10 774 in
adamc@11 775 case #1 (hnormCon env et) of
adamc@11 776 L'.CError => (eerror, cerror)
adamc@11 777 | L'.TCFun (_, _, k, eb) =>
adamc@11 778 let
adamc@11 779 val () = checkKind env c' ck k
adamc@11 780 val eb' = subConInCon (0, c') eb
adamc@11 781 handle SynUnif => (expError env (Unif ("substitution", eb));
adamc@11 782 cerror)
adamc@11 783 in
adamc@11 784 ((L'.ECApp (e', c'), loc), eb')
adamc@11 785 end
adamc@11 786
adamc@11 787 | L'.CUnif _ =>
adamc@11 788 (expError env (Unif ("application", et));
adamc@11 789 (eerror, cerror))
adamc@11 790
adamc@11 791 | _ =>
adamc@11 792 (expError env (WrongForm ("constructor function", e', et));
adamc@11 793 (eerror, cerror))
adamc@10 794 end
adamc@11 795 | L.ECAbs (expl, x, k, e) =>
adamc@11 796 let
adamc@11 797 val expl' = elabExplicitness expl
adamc@11 798 val k' = elabKind k
adamc@11 799 val (e', et) = elabExp (E.pushCRel env x k') e
adamc@11 800 in
adamc@11 801 ((L'.ECAbs (expl', x, k', e'), loc),
adamc@11 802 (L'.TCFun (expl', x, k', et), loc))
adamc@11 803 end
adamc@6 804
adamc@12 805 | L.ERecord xes =>
adamc@12 806 let
adamc@12 807 val xes' = map (fn (x, e) =>
adamc@12 808 let
adamc@12 809 val (x', xk) = elabCon env x
adamc@12 810 val (e', et) = elabExp env e
adamc@12 811 in
adamc@12 812 checkKind env x' xk kname;
adamc@12 813 (x', e', et)
adamc@12 814 end) xes
adamc@12 815 in
adamc@12 816 ((L'.ERecord (map (fn (x', e', _) => (x', e')) xes'), loc),
adamc@12 817 (L'.TRecord (L'.CRecord (ktype, map (fn (x', _, et) => (x', et)) xes'), loc), loc))
adamc@12 818 end
adamc@12 819
adamc@12 820 | L.EField (e, c) =>
adamc@12 821 let
adamc@12 822 val (e', et) = elabExp env e
adamc@12 823 val (c', ck) = elabCon env c
adamc@12 824
adamc@12 825 val ft = cunif ktype
adamc@12 826 val rest = cunif ktype_record
adamc@12 827 in
adamc@12 828 checkKind env c' ck kname;
adamc@12 829 checkCon env e' et (L'.TRecord (L'.CConcat ((L'.CRecord (ktype, [(c', ft)]), loc), rest), loc), loc);
adamc@12 830 ((L'.EField (e', c', {field = ft, rest = rest}), loc), ft)
adamc@12 831 end
adamc@12 832
adamc@12 833
adamc@6 834 datatype decl_error =
adamc@6 835 KunifsRemainKind of ErrorMsg.span * L'.kind
adamc@6 836 | KunifsRemainCon of ErrorMsg.span * L'.con
adamc@10 837 | KunifsRemainExp of ErrorMsg.span * L'.exp
adamc@10 838 | CunifsRemainCon of ErrorMsg.span * L'.con
adamc@10 839 | CunifsRemainExp of ErrorMsg.span * L'.exp
adamc@6 840
adamc@6 841 fun declError env err =
adamc@6 842 case err of
adamc@6 843 KunifsRemainKind (loc, k) =>
adamc@6 844 (ErrorMsg.errorAt loc "Some kind unification variables are undetermined in kind";
adamc@6 845 eprefaces' [("Kind", p_kind k)])
adamc@6 846 | KunifsRemainCon (loc, c) =>
adamc@6 847 (ErrorMsg.errorAt loc "Some kind unification variables are undetermined in constructor";
adamc@6 848 eprefaces' [("Constructor", p_con env c)])
adamc@10 849 | KunifsRemainExp (loc, e) =>
adamc@10 850 (ErrorMsg.errorAt loc "Some kind unification variables are undetermined in expression";
adamc@10 851 eprefaces' [("Expression", p_exp env e)])
adamc@10 852 | CunifsRemainCon (loc, c) =>
adamc@10 853 (ErrorMsg.errorAt loc "Some constructor unification variables are undetermined in constructor";
adamc@10 854 eprefaces' [("Constructor", p_con env c)])
adamc@10 855 | CunifsRemainExp (loc, e) =>
adamc@10 856 (ErrorMsg.errorAt loc "Some constructor unification variables are undetermined in expression";
adamc@10 857 eprefaces' [("Expression", p_exp env e)])
adamc@6 858
adamc@3 859 fun elabDecl env (d, loc) =
adamc@5 860 (resetKunif ();
adamc@12 861 resetCunif ();
adamc@5 862 case d of
adamc@5 863 L.DCon (x, ko, c) =>
adamc@5 864 let
adamc@5 865 val k' = case ko of
adamc@5 866 NONE => kunif ()
adamc@5 867 | SOME k => elabKind k
adamc@3 868
adamc@5 869 val (c', ck) = elabCon env c
adamc@11 870 val (env', n) = E.pushCNamed env x k' (SOME c')
adamc@5 871 in
adamc@5 872 checkKind env c' ck k';
adamc@6 873
adamc@15 874 if ErrorMsg.anyErrors () then
adamc@15 875 ()
adamc@15 876 else (
adamc@15 877 if kunifsInKind k' then
adamc@15 878 declError env (KunifsRemainKind (loc, k'))
adamc@15 879 else
adamc@15 880 ();
adamc@6 881
adamc@15 882 if kunifsInCon c' then
adamc@15 883 declError env (KunifsRemainCon (loc, c'))
adamc@15 884 else
adamc@15 885 ()
adamc@15 886 );
adamc@6 887
adamc@5 888 (env',
adamc@5 889 (L'.DCon (x, n, k', c'), loc))
adamc@10 890 end
adamc@10 891 | L.DVal (x, co, e) =>
adamc@10 892 let
adamc@10 893 val (c', ck) = case co of
adamc@10 894 NONE => (cunif ktype, ktype)
adamc@10 895 | SOME c => elabCon env c
adamc@10 896
adamc@10 897 val (e', et) = elabExp env e
adamc@10 898 val (env', n) = E.pushENamed env x c'
adamc@10 899 in
adamc@10 900 checkCon env e' et c';
adamc@10 901
adamc@15 902 if ErrorMsg.anyErrors () then
adamc@15 903 ()
adamc@15 904 else (
adamc@15 905 if kunifsInCon c' then
adamc@15 906 declError env (KunifsRemainCon (loc, c'))
adamc@15 907 else
adamc@15 908 ();
adamc@10 909
adamc@15 910 if cunifsInCon c' then
adamc@15 911 declError env (CunifsRemainCon (loc, c'))
adamc@15 912 else
adamc@15 913 ();
adamc@10 914
adamc@15 915 if kunifsInExp e' then
adamc@15 916 declError env (KunifsRemainExp (loc, e'))
adamc@15 917 else
adamc@15 918 ();
adamc@10 919
adamc@15 920 if cunifsInExp e' then
adamc@15 921 declError env (CunifsRemainExp (loc, e'))
adamc@15 922 else
adamc@15 923 ());
adamc@10 924
adamc@10 925 (env',
adamc@10 926 (L'.DVal (x, n, c', e'), loc))
adamc@5 927 end)
adamc@3 928
adamc@5 929 fun elabFile env ds =
adamc@5 930 ListUtil.mapfoldl (fn (d, env) => elabDecl env d) env ds
adamc@2 931
adamc@2 932 end