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Add tuple pattern-matching at the constructor level
author Adam Chlipala <adamc@hcoop.net>
date Tue, 20 Oct 2009 10:19:00 -0400
parents 46803e668a89
children a779402841f6
rev   line source
adamc@81 1 (* Copyright (c) 2008, Adam Chlipala
adamc@81 2 * All rights reserved.
adamc@81 3 *
adamc@81 4 * Redistribution and use in source and binary forms, with or without
adamc@81 5 * modification, are permitted provided that the following conditions are met:
adamc@81 6 *
adamc@81 7 * - Redistributions of source code must retain the above copyright notice,
adamc@81 8 * this list of conditions and the following disclaimer.
adamc@81 9 * - Redistributions in binary form must reproduce the above copyright notice,
adamc@81 10 * this list of conditions and the following disclaimer in the documentation
adamc@81 11 * and/or other materials provided with the distribution.
adamc@81 12 * - The names of contributors may not be used to endorse or promote products
adamc@81 13 * derived from this software without specific prior written permission.
adamc@81 14 *
adamc@81 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
adamc@81 16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
adamc@81 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
adamc@81 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
adamc@81 19 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
adamc@81 20 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
adamc@81 21 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
adamc@81 22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
adamc@81 23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
adamc@81 24 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
adamc@81 25 * POSSIBILITY OF SUCH DAMAGE.
adamc@81 26 *)
adamc@81 27
adamc@81 28 structure ElabOps :> ELAB_OPS = struct
adamc@81 29
adamc@81 30 open Elab
adamc@81 31
adamc@81 32 structure E = ElabEnv
adamc@81 33 structure U = ElabUtil
adamc@81 34
adamc@623 35 fun liftKindInKind' by =
adamc@623 36 U.Kind.mapB {kind = fn bound => fn k =>
adamc@623 37 case k of
adamc@623 38 KRel xn =>
adamc@623 39 if xn < bound then
adamc@623 40 k
adamc@623 41 else
adamc@623 42 KRel (xn + by)
adamc@623 43 | _ => k,
adamc@623 44 bind = fn (bound, _) => bound + 1}
adamc@623 45
adamc@623 46 fun subKindInKind' rep =
adamc@623 47 U.Kind.mapB {kind = fn (by, xn) => fn k =>
adamc@623 48 case k of
adamc@623 49 KRel xn' =>
adamc@623 50 (case Int.compare (xn', xn) of
adamc@623 51 EQUAL => #1 (liftKindInKind' by 0 rep)
adamc@623 52 | GREATER => KRel (xn' - 1)
adamc@623 53 | LESS => k)
adamc@623 54 | _ => k,
adamc@623 55 bind = fn ((by, xn), _) => (by+1, xn+1)}
adamc@623 56
adamc@623 57 val liftKindInKind = liftKindInKind' 1
adamc@623 58
adamc@623 59 fun subKindInKind (xn, rep) = subKindInKind' rep (0, xn)
adamc@623 60
adamc@623 61 fun liftKindInCon by =
adamc@623 62 U.Con.mapB {kind = fn bound => fn k =>
adamc@623 63 case k of
adamc@623 64 KRel xn =>
adamc@623 65 if xn < bound then
adamc@623 66 k
adamc@623 67 else
adamc@623 68 KRel (xn + by)
adamc@623 69 | _ => k,
adamc@623 70 con = fn _ => fn c => c,
adamc@623 71 bind = fn (bound, U.Con.RelK _) => bound + 1
adamc@623 72 | (bound, _) => bound}
adamc@623 73
adamc@623 74 fun subKindInCon' rep =
adamc@623 75 U.Con.mapB {kind = fn (by, xn) => fn k =>
adamc@623 76 case k of
adamc@623 77 KRel xn' =>
adamc@623 78 (case Int.compare (xn', xn) of
adamc@623 79 EQUAL => #1 (liftKindInKind' by 0 rep)
adamc@623 80 | GREATER => KRel (xn' - 1)
adamc@623 81 | LESS => k)
adamc@623 82 | _ => k,
adamc@623 83 con = fn _ => fn c => c,
adamc@623 84 bind = fn ((by, xn), U.Con.RelK _) => (by+1, xn+1)
adamc@623 85 | (st, _) => st}
adamc@623 86
adamc@623 87 val liftKindInCon = liftKindInCon 1
adamc@623 88
adamc@623 89 fun subKindInCon (xn, rep) = subKindInCon' rep (0, xn)
adamc@623 90
adamc@516 91 fun liftConInCon by =
adamc@623 92 U.Con.mapB {kind = fn _ => fn k => k,
adamc@516 93 con = fn bound => fn c =>
adamc@516 94 case c of
adamc@516 95 CRel xn =>
adamc@516 96 if xn < bound then
adamc@516 97 c
adamc@516 98 else
adamc@516 99 CRel (xn + by)
adamc@516 100 (*| CUnif _ => raise SynUnif*)
adamc@516 101 | _ => c,
adamc@623 102 bind = fn (bound, U.Con.RelC _) => bound + 1
adamc@516 103 | (bound, _) => bound}
adamc@81 104
adamc@516 105 fun subConInCon' rep =
adamc@623 106 U.Con.mapB {kind = fn _ => fn k => k,
adamc@516 107 con = fn (by, xn) => fn c =>
adamc@516 108 case c of
adamc@516 109 CRel xn' =>
adamc@516 110 (case Int.compare (xn', xn) of
adamc@516 111 EQUAL => #1 (liftConInCon by 0 rep)
adamc@516 112 | GREATER => CRel (xn' - 1)
adamc@516 113 | LESS => c)
adamc@516 114 (*| CUnif _ => raise SynUnif*)
adamc@516 115 | _ => c,
adamc@623 116 bind = fn ((by, xn), U.Con.RelC _) => (by+1, xn+1)
adamc@81 117 | (ctx, _) => ctx}
adamc@81 118
adamc@516 119 val liftConInCon = liftConInCon 1
adamc@516 120
adamc@516 121 fun subConInCon (xn, rep) = subConInCon' rep (0, xn)
adamc@516 122
adamc@81 123 fun subStrInSgn (m1, m2) =
adamc@81 124 U.Sgn.map {kind = fn k => k,
adamc@81 125 con = fn c as CModProj (m1', ms, x) =>
adamc@81 126 if m1 = m1' then
adamc@81 127 CModProj (m2, ms, x)
adamc@81 128 else
adamc@81 129 c
adamc@81 130 | c => c,
adamc@81 131 sgn_item = fn sgi => sgi,
adamc@81 132 sgn = fn sgn => sgn}
adamc@81 133
adamc@905 134 val occurs =
adamc@905 135 U.Con.existsB {kind = fn _ => false,
adamc@905 136 con = fn (n, c) =>
adamc@905 137 case c of
adamc@905 138 CRel n' => n' = n
adamc@905 139 | _ => false,
adamc@905 140 bind = fn (n, b) =>
adamc@905 141 case b of
adamc@905 142 U.Con.RelC _ => n + 1
adamc@905 143 | _ => n}
adamc@905 144 0
adamc@905 145
adamc@81 146
adamc@81 147 fun hnormCon env (cAll as (c, loc)) =
adamc@81 148 case c of
adamc@81 149 CUnif (_, _, _, ref (SOME c)) => hnormCon env c
adamc@81 150
adamc@81 151 | CNamed xn =>
adamc@81 152 (case E.lookupCNamed env xn of
adamc@81 153 (_, _, SOME c') => hnormCon env c'
adamc@81 154 | _ => cAll)
adamc@81 155
adamc@81 156 | CModProj (n, ms, x) =>
adamc@81 157 let
adamc@81 158 val (_, sgn) = E.lookupStrNamed env n
adamc@81 159 val (str, sgn) = foldl (fn (m, (str, sgn)) =>
adamc@81 160 case E.projectStr env {sgn = sgn, str = str, field = m} of
adamc@81 161 NONE => raise Fail "hnormCon: Unknown substructure"
adamc@81 162 | SOME sgn => ((StrProj (str, m), loc), sgn))
adamc@81 163 ((StrVar n, loc), sgn) ms
adamc@81 164 in
adamc@81 165 case E.projectCon env {sgn = sgn, str = str, field = x} of
adamc@81 166 NONE => raise Fail "kindof: Unknown con in structure"
adamc@81 167 | SOME (_, NONE) => cAll
adamc@81 168 | SOME (_, SOME c) => hnormCon env c
adamc@81 169 end
adamc@81 170
adamc@905 171 (* Eta reduction *)
adamc@905 172 | CAbs (x, k, b) =>
adamc@905 173 (case #1 (hnormCon (E.pushCRel env x k) b) of
adamc@905 174 CApp (f, (CRel 0, _)) =>
adamc@905 175 if occurs f then
adamc@905 176 cAll
adamc@905 177 else
adamc@905 178 hnormCon env (subConInCon (0, (CUnit, loc)) f)
adamc@905 179 | _ => cAll)
adamc@905 180
adamc@81 181 | CApp (c1, c2) =>
adamc@81 182 (case #1 (hnormCon env c1) of
adamc@81 183 CAbs (x, k, cb) =>
adamc@81 184 let
adamc@81 185 val sc = (hnormCon env (subConInCon (0, c2) cb))
adamc@81 186 handle SynUnif => cAll
adamc@81 187 (*val env' = E.pushCRel env x k*)
adamc@81 188 in
adamc@328 189 (*Print.eprefaces "Subst" [("x", Print.PD.string x),
adamc@328 190 ("cb", ElabPrint.p_con env' cb),
adamc@328 191 ("c2", ElabPrint.p_con env c2),
adamc@328 192 ("sc", ElabPrint.p_con env sc)];*)
adamc@81 193 sc
adamc@81 194 end
adamc@621 195 | c1' as CApp (c', f) =>
adamc@326 196 let
adamc@326 197 fun default () = (CApp ((c1', loc), hnormCon env c2), loc)
adamc@326 198 in
adamc@326 199 case #1 (hnormCon env c') of
adamc@621 200 CMap (ks as (k1, k2)) =>
adamc@621 201 (case #1 (hnormCon env c2) of
adamc@621 202 CRecord (_, []) => (CRecord (k2, []), loc)
adamc@621 203 | CRecord (_, (x, c) :: rest) =>
adamc@621 204 hnormCon env
adamc@621 205 (CConcat ((CRecord (k2, [(x, (CApp (f, c), loc))]), loc),
adamc@621 206 (CApp (c1, (CRecord (k2, rest), loc)), loc)), loc)
adamc@621 207 | CConcat ((CRecord (k, (x, c) :: rest), _), rest') =>
adamc@621 208 let
adamc@621 209 val rest'' = (CConcat ((CRecord (k, rest), loc), rest'), loc)
adamc@621 210 in
adamc@621 211 hnormCon env
adamc@621 212 (CConcat ((CRecord (k2, [(x, (CApp (f, c), loc))]), loc),
adamc@621 213 (CApp (c1, rest''), loc)), loc)
adamc@621 214 end
adamc@621 215 | _ =>
adamc@621 216 let
adamc@621 217 fun unconstraint c =
adamc@621 218 case hnormCon env c of
adamc@628 219 (TDisjoint (_, _, c), _) => unconstraint c
adamc@621 220 | c => c
adamc@81 221
adamc@621 222 fun tryDistributivity () =
adamc@621 223 case hnormCon env c2 of
adamc@621 224 (CConcat (c1, c2'), _) =>
adamc@621 225 let
adamc@621 226 val c = (CMap ks, loc)
adamc@621 227 val c = (CApp (c, f), loc)
adamc@621 228
adamc@621 229 val c1 = (CApp (c, c1), loc)
adamc@621 230 val c2 = (CApp (c, c2'), loc)
adamc@621 231 val c = (CConcat (c1, c2), loc)
adamc@621 232 in
adamc@621 233 hnormCon env c
adamc@621 234 end
adamc@621 235 | _ => default ()
adamc@329 236
adamc@621 237 fun tryFusion () =
adamc@621 238 case #1 (hnormCon env c2) of
adamc@621 239 CApp (f', r') =>
adamc@621 240 (case #1 (hnormCon env f') of
adamc@621 241 CApp (f', inner_f) =>
adamc@621 242 (case #1 (hnormCon env f') of
adamc@621 243 CMap (dom, _) =>
adamc@621 244 let
adamc@990 245 val inner_f = liftConInCon 0 inner_f
adamc@990 246 val f = liftConInCon 0 f
adamc@990 247
adamc@621 248 val f' = (CApp (inner_f, (CRel 0, loc)), loc)
adamc@621 249 val f' = (CApp (f, f'), loc)
adamc@621 250 val f' = (CAbs ("v", dom, f'), loc)
adamc@329 251
adamc@621 252 val c = (CMap (dom, k2), loc)
adamc@621 253 val c = (CApp (c, f'), loc)
adamc@621 254 val c = (CApp (c, r'), loc)
adamc@621 255 in
adamc@621 256 hnormCon env c
adamc@621 257 end
adamc@621 258 | _ => tryDistributivity ())
adamc@621 259 | _ => tryDistributivity ())
adamc@621 260 | _ => tryDistributivity ()
adamc@339 261
adamc@621 262 fun tryIdentity () =
adamc@621 263 let
adamc@621 264 fun cunif () =
adamc@621 265 let
adamc@621 266 val r = ref NONE
adamc@621 267 in
adamc@621 268 (r, (CUnif (loc, (KType, loc), "_", r), loc))
adamc@621 269 end
adamc@621 270
adamc@621 271 val (vR, v) = cunif ()
adamc@494 272
adamc@621 273 val c = (CApp (f, v), loc)
adamc@621 274 in
adamc@621 275 case unconstraint c of
adamc@621 276 (CUnif (_, _, _, vR'), _) =>
adamc@621 277 if vR' = vR then
adamc@621 278 hnormCon env c2
adamc@621 279 else
adamc@621 280 tryFusion ()
adamc@621 281 | _ => tryFusion ()
adamc@621 282 end
adamc@621 283 in
adamc@621 284 tryIdentity ()
adamc@621 285 end)
adamc@326 286 | _ => default ()
adamc@326 287 end
adamc@326 288 | c1' => (CApp ((c1', loc), hnormCon env c2), loc))
adamc@623 289
adamc@623 290 | CKApp (c1, k) =>
adamc@623 291 (case hnormCon env c1 of
adamc@623 292 (CKAbs (_, body), _) => hnormCon env (subKindInCon (0, k) body)
adamc@623 293 | _ => cAll)
adamc@621 294
adamc@81 295 | CConcat (c1, c2) =>
adamc@81 296 (case (hnormCon env c1, hnormCon env c2) of
adamc@81 297 ((CRecord (k, xcs1), loc), (CRecord (_, xcs2), _)) =>
adamc@81 298 (CRecord (k, xcs1 @ xcs2), loc)
adamc@81 299 | ((CRecord (_, []), _), c2') => c2'
adamc@81 300 | ((CConcat (c11, c12), loc), c2') =>
adamc@81 301 hnormCon env (CConcat (c11, (CConcat (c12, c2'), loc)), loc)
adamc@209 302 | (c1', (CRecord (_, []), _)) => c1'
adamc@329 303 | (c1', c2') => (CConcat (c1', c2'), loc))
adamc@81 304
adamc@207 305 | CProj (c, n) =>
adamc@207 306 (case hnormCon env c of
adamc@207 307 (CTuple cs, _) => hnormCon env (List.nth (cs, n - 1))
adamc@207 308 | _ => cAll)
adamc@207 309
adamc@81 310 | _ => cAll
adamc@81 311
adamc@81 312 end