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annotate src/mono_reduce.sml @ 696:79a49c509007

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Avoid generating empty <script> blocks
author Adam Chlipala <adamc@hcoop.net>
date Sun, 05 Apr 2009 09:26:00 -0400
parents 500e93aa436f
children 755a71c99be5
rev   line source
adamc@133 1 (* Copyright (c) 2008, Adam Chlipala
adamc@133 2 * All rights reserved.
adamc@133 3 *
adamc@133 4 * Redistribution and use in source and binary forms, with or without
adamc@133 5 * modification, are permitted provided that the following conditions are met:
adamc@133 6 *
adamc@133 7 * - Redistributions of source code must retain the above copyright notice,
adamc@133 8 * this list of conditions and the following disclaimer.
adamc@133 9 * - Redistributions in binary form must reproduce the above copyright notice,
adamc@133 10 * this list of conditions and the following disclaimer in the documentation
adamc@133 11 * and/or other materials provided with the distribution.
adamc@133 12 * - The names of contributors may not be used to endorse or promote products
adamc@133 13 * derived from this software without specific prior written permission.
adamc@133 14 *
adamc@133 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
adamc@133 16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
adamc@133 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
adamc@133 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
adamc@133 19 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
adamc@133 20 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
adamc@133 21 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
adamc@133 22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
adamc@133 23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
adamc@133 24 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
adamc@133 25 * POSSIBILITY OF SUCH DAMAGE.
adamc@133 26 *)
adamc@133 27
adamc@133 28 (* Simplify a Mono program algebraically *)
adamc@133 29
adamc@133 30 structure MonoReduce :> MONO_REDUCE = struct
adamc@133 31
adamc@133 32 open Mono
adamc@133 33
adamc@133 34 structure E = MonoEnv
adamc@133 35 structure U = MonoUtil
adamc@133 36
adamc@470 37 structure IM = IntBinaryMap
adamc@470 38
adamc@133 39
adamc@252 40 fun impure (e, _) =
adamc@252 41 case e of
adamc@252 42 EWrite _ => true
adamc@252 43 | EQuery _ => true
adamc@307 44 | EDml _ => true
adamc@338 45 | ENextval _ => true
adamc@463 46 | EUnurlify _ => true
adamc@252 47 | EAbs _ => false
adamc@252 48
adamc@252 49 | EPrim _ => false
adamc@252 50 | ERel _ => false
adamc@252 51 | ENamed _ => false
adamc@252 52 | ECon (_, _, eo) => (case eo of NONE => false | SOME e => impure e)
adamc@297 53 | ENone _ => false
adamc@290 54 | ESome (_, e) => impure e
adamc@252 55 | EFfi _ => false
adamc@462 56 | EFfiApp ("Basis", "set_cookie", _) => true
adamc@565 57 | EFfiApp ("Basis", "new_client_source", _) => true
adamc@690 58 | EFfiApp ("Basis", "get_client_source", _) => true
adamc@577 59 | EFfiApp ("Basis", "set_client_source", _) => true
adamc@579 60 | EFfiApp ("Basis", "alert", _) => true
adamc@668 61 | EFfiApp ("Basis", "new_channel", _) => true
adamc@668 62 | EFfiApp ("Basis", "subscribe", _) => true
adamc@668 63 | EFfiApp ("Basis", "send", _) => true
adamc@694 64 | EFfiApp ("Basis", "recv", _) => true
adamc@252 65 | EFfiApp _ => false
adamc@252 66 | EApp ((EFfi _, _), _) => false
adamc@252 67 | EApp _ => true
adamc@252 68
adamc@387 69 | EUnop (_, e) => impure e
adamc@387 70 | EBinop (_, e1, e2) => impure e1 orelse impure e2
adamc@387 71
adamc@252 72 | ERecord xes => List.exists (fn (_, e, _) => impure e) xes
adamc@252 73 | EField (e, _) => impure e
adamc@252 74
adamc@252 75 | ECase (e, pes, _) => impure e orelse List.exists (fn (_, e) => impure e) pes
adamc@252 76
adamc@283 77 | EError (e, _) => impure e
adamc@283 78
adamc@252 79 | EStrcat (e1, e2) => impure e1 orelse impure e2
adamc@252 80
adamc@252 81 | ESeq (e1, e2) => impure e1 orelse impure e2
adamc@252 82 | ELet (_, _, e1, e2) => impure e1 orelse impure e2
adamc@252 83
adamc@252 84 | EClosure (_, es) => List.exists impure es
adamc@578 85 | EJavaScript (_, e, _) => impure e
adamc@568 86 | ESignalReturn e => impure e
adamc@572 87 | ESignalBind (e1, e2) => impure e1 orelse impure e2
adamc@574 88 | ESignalSource e => impure e
adamc@608 89 | EServerCall _ => true
adamc@670 90 | ERecv _ => true
adamc@695 91 | ESleep _ => true
adamc@252 92
adamc@252 93
adamc@252 94 val liftExpInExp = Monoize.liftExpInExp
adamc@252 95
adamc@252 96 val subExpInExp' =
adamc@133 97 U.Exp.mapB {typ = fn t => t,
adamc@133 98 exp = fn (xn, rep) => fn e =>
adamc@133 99 case e of
adamc@133 100 ERel xn' =>
adamc@133 101 (case Int.compare (xn', xn) of
adamc@133 102 EQUAL => #1 rep
adamc@133 103 | GREATER=> ERel (xn' - 1)
adamc@133 104 | LESS => e)
adamc@133 105 | _ => e,
adamc@133 106 bind = fn ((xn, rep), U.Exp.RelE _) => (xn+1, liftExpInExp 0 rep)
adamc@133 107 | (ctx, _) => ctx}
adamc@133 108
adamc@252 109 fun subExpInExp (n, e1) e2 =
adamc@252 110 let
adamc@252 111 val r = subExpInExp' (n, e1) e2
adamc@252 112 in
adamc@252 113 (*Print.prefaces "subExpInExp" [("e1", MonoPrint.p_exp MonoEnv.empty e1),
adamc@252 114 ("e2", MonoPrint.p_exp MonoEnv.empty e2),
adamc@252 115 ("r", MonoPrint.p_exp MonoEnv.empty r)];*)
adamc@252 116 r
adamc@252 117 end
adamc@133 118
adamc@133 119 fun typ c = c
adamc@133 120
adamc@316 121 val swapExpVars =
adamc@316 122 U.Exp.mapB {typ = fn t => t,
adamc@316 123 exp = fn lower => fn e =>
adamc@316 124 case e of
adamc@316 125 ERel xn =>
adamc@316 126 if xn = lower then
adamc@316 127 ERel (lower + 1)
adamc@316 128 else if xn = lower + 1 then
adamc@316 129 ERel lower
adamc@316 130 else
adamc@316 131 e
adamc@316 132 | _ => e,
adamc@316 133 bind = fn (lower, U.Exp.RelE _) => lower+1
adamc@316 134 | (lower, _) => lower}
adamc@316 135
adamc@341 136 val swapExpVarsPat =
adamc@341 137 U.Exp.mapB {typ = fn t => t,
adamc@341 138 exp = fn (lower, len) => fn e =>
adamc@341 139 case e of
adamc@341 140 ERel xn =>
adamc@341 141 if xn = lower then
adamc@341 142 ERel (lower + 1)
adamc@341 143 else if xn >= lower + 1 andalso xn < lower + 1 + len then
adamc@341 144 ERel (xn - 1)
adamc@341 145 else
adamc@341 146 e
adamc@341 147 | _ => e,
adamc@341 148 bind = fn ((lower, len), U.Exp.RelE _) => (lower+1, len)
adamc@341 149 | (st, _) => st}
adamc@341 150
adamc@258 151 datatype result = Yes of E.env | No | Maybe
adamc@258 152
adamc@183 153 fun match (env, p : pat, e : exp) =
adamc@183 154 case (#1 p, #1 e) of
adamc@258 155 (PWild, _) => Yes env
adamc@258 156 | (PVar (x, t), _) => Yes (E.pushERel env x t (SOME e))
adamc@183 157
adamc@280 158 | (PPrim (Prim.String s), EStrcat ((EPrim (Prim.String s'), _), _)) =>
adamc@280 159 if String.isPrefix s' s then
adamc@280 160 Maybe
adamc@280 161 else
adamc@280 162 No
adamc@280 163
adamc@183 164 | (PPrim p, EPrim p') =>
adamc@183 165 if Prim.equal (p, p') then
adamc@258 166 Yes env
adamc@183 167 else
adamc@258 168 No
adamc@183 169
adamc@188 170 | (PCon (_, PConVar n1, NONE), ECon (_, PConVar n2, NONE)) =>
adamc@183 171 if n1 = n2 then
adamc@258 172 Yes env
adamc@183 173 else
adamc@258 174 No
adamc@183 175
adamc@188 176 | (PCon (_, PConVar n1, SOME p), ECon (_, PConVar n2, SOME e)) =>
adamc@183 177 if n1 = n2 then
adamc@183 178 match (env, p, e)
adamc@183 179 else
adamc@258 180 No
adamc@183 181
adamc@188 182 | (PCon (_, PConFfi {mod = m1, con = con1, ...}, NONE), ECon (_, PConFfi {mod = m2, con = con2, ...}, NONE)) =>
adamc@185 183 if m1 = m2 andalso con1 = con2 then
adamc@258 184 Yes env
adamc@185 185 else
adamc@258 186 No
adamc@185 187
adamc@188 188 | (PCon (_, PConFfi {mod = m1, con = con1, ...}, SOME ep), ECon (_, PConFfi {mod = m2, con = con2, ...}, SOME e)) =>
adamc@185 189 if m1 = m2 andalso con1 = con2 then
adamc@185 190 match (env, p, e)
adamc@185 191 else
adamc@258 192 No
adamc@185 193
adamc@183 194 | (PRecord xps, ERecord xes) =>
adamc@183 195 let
adamc@183 196 fun consider (xps, env) =
adamc@183 197 case xps of
adamc@258 198 [] => Yes env
adamc@183 199 | (x, p, _) :: rest =>
adamc@183 200 case List.find (fn (x', _, _) => x' = x) xes of
adamc@258 201 NONE => No
adamc@183 202 | SOME (_, e, _) =>
adamc@183 203 case match (env, p, e) of
adamc@258 204 No => No
adamc@258 205 | Maybe => Maybe
adamc@258 206 | Yes env => consider (rest, env)
adamc@183 207 in
adamc@183 208 consider (xps, env)
adamc@183 209 end
adamc@183 210
adamc@258 211 | _ => Maybe
adamc@183 212
adamc@318 213 datatype event =
adamc@318 214 WritePage
adamc@318 215 | ReadDb
adamc@318 216 | WriteDb
adamc@481 217 | UseRel
adamc@318 218 | Unsure
adamc@318 219
adamc@318 220 fun p_event e =
adamc@318 221 let
adamc@318 222 open Print.PD
adamc@318 223 in
adamc@318 224 case e of
adamc@318 225 WritePage => string "WritePage"
adamc@318 226 | ReadDb => string "ReadDb"
adamc@318 227 | WriteDb => string "WriteDb"
adamc@481 228 | UseRel => string "UseRel"
adamc@318 229 | Unsure => string "Unsure"
adamc@318 230 end
adamc@318 231
adamc@470 232 val p_events = Print.p_list p_event
adamc@470 233
adamc@318 234 fun patBinds (p, _) =
adamc@318 235 case p of
adamc@318 236 PWild => 0
adamc@318 237 | PVar _ => 1
adamc@318 238 | PPrim _ => 0
adamc@318 239 | PCon (_, _, NONE) => 0
adamc@318 240 | PCon (_, _, SOME p) => patBinds p
adamc@318 241 | PRecord xpts => foldl (fn ((_, p, _), n) => n + patBinds p) 0 xpts
adamc@318 242 | PNone _ => 0
adamc@318 243 | PSome (_, p) => patBinds p
adamc@318 244
adamc@470 245 fun reduce file =
adamc@470 246 let
adamc@470 247 fun countAbs (e, _) =
adamc@470 248 case e of
adamc@470 249 EAbs (_, _, _, e) => 1 + countAbs e
adamc@470 250 | _ => 0
adamc@318 251
adamc@470 252 val absCounts =
adamc@470 253 foldl (fn ((d, _), absCounts) =>
adamc@470 254 case d of
adamc@470 255 DVal (_, n, _, e, _) =>
adamc@470 256 IM.insert (absCounts, n, countAbs e)
adamc@470 257 | DValRec vis =>
adamc@470 258 foldl (fn ((_, n, _, e, _), absCounts) =>
adamc@470 259 IM.insert (absCounts, n, countAbs e))
adamc@470 260 absCounts vis
adamc@470 261 | _ => absCounts)
adamc@470 262 IM.empty file
adamc@387 263
adamc@470 264 fun summarize d (e, _) =
adamc@579 265 let
adamc@668 266 fun ffi es = List.concat (map (summarize d) es) @ [Unsure]
adamc@668 267
adamc@579 268 val s =
adamc@579 269 case e of
adamc@579 270 EPrim _ => []
adamc@579 271 | ERel n => if n = d then [UseRel] else []
adamc@579 272 | ENamed _ => []
adamc@579 273 | ECon (_, _, NONE) => []
adamc@579 274 | ECon (_, _, SOME e) => summarize d e
adamc@579 275 | ENone _ => []
adamc@579 276 | ESome (_, e) => summarize d e
adamc@579 277 | EFfi _ => []
adamc@668 278 | EFfiApp ("Basis", "set_cookie", es) => ffi es
adamc@668 279 | EFfiApp ("Basis", "new_client_source", es) => ffi es
adamc@690 280 | EFfiApp ("Basis", "get_client_source", es) => ffi es
adamc@668 281 | EFfiApp ("Basis", "set_client_source", es) => ffi es
adamc@668 282 | EFfiApp ("Basis", "alert", es) => ffi es
adamc@668 283 | EFfiApp ("Basis", "new_channel", es) => ffi es
adamc@668 284 | EFfiApp ("Basis", "subscribe", es) => ffi es
adamc@668 285 | EFfiApp ("Basis", "send", es) => ffi es
adamc@694 286 | EFfiApp ("Basis", "recv", es) => ffi es
adamc@579 287 | EFfiApp (_, _, es) => List.concat (map (summarize d) es)
adamc@579 288 | EApp ((EFfi _, _), e) => summarize d e
adamc@579 289 | EApp _ =>
adamc@579 290 let
adamc@694 291 fun unravel (e, passed, ls) =
adamc@579 292 case e of
adamc@579 293 ENamed n =>
adamc@579 294 let
adamc@579 295 val ls = rev ls
adamc@579 296 in
adamc@579 297 case IM.find (absCounts, n) of
adamc@579 298 NONE => [Unsure]
adamc@579 299 | SOME len =>
adamc@694 300 if passed < len then
adamc@579 301 ls
adamc@579 302 else
adamc@694 303 ls @ [Unsure]
adamc@579 304 end
adamc@579 305 | ERel n => List.revAppend (ls,
adamc@579 306 if n = d then
adamc@579 307 [UseRel, Unsure]
adamc@579 308 else
adamc@579 309 [Unsure])
adamc@579 310 | EApp (f, x) =>
adamc@694 311 unravel (#1 f, passed + 1, summarize d x @ ls)
adamc@579 312 | _ => [Unsure]
adamc@579 313 in
adamc@694 314 unravel (e, 0, [])
adamc@579 315 end
adamc@252 316
adamc@579 317 | EAbs (_, _, _, e) => List.filter (fn UseRel => true
adamc@579 318 | _ => false) (summarize (d + 1) e)
adamc@316 319
adamc@579 320 | EUnop (_, e) => summarize d e
adamc@579 321 | EBinop (_, e1, e2) => summarize d e1 @ summarize d e2
adamc@470 322
adamc@579 323 | ERecord xets => List.concat (map (summarize d o #2) xets)
adamc@579 324 | EField (e, _) => summarize d e
adamc@470 325
adamc@579 326 | ECase (e, pes, _) =>
adamc@579 327 let
adamc@579 328 val lss = map (fn (p, e) => summarize (d + patBinds p) e) pes
adamc@579 329 in
adamc@579 330 case lss of
adamc@579 331 [] => raise Fail "Empty pattern match"
adamc@579 332 | ls :: lss =>
adamc@579 333 if List.all (fn ls' => ls' = ls) lss then
adamc@579 334 summarize d e @ ls
adamc@579 335 else
adamc@579 336 [Unsure]
adamc@579 337 end
adamc@579 338 | EStrcat (e1, e2) => summarize d e1 @ summarize d e2
adamc@316 339
adamc@579 340 | EError (e, _) => summarize d e @ [Unsure]
adamc@318 341
adamc@579 342 | EWrite e => summarize d e @ [WritePage]
adamc@579 343
adamc@579 344 | ESeq (e1, e2) => summarize d e1 @ summarize d e2
adamc@579 345 | ELet (_, _, e1, e2) => summarize d e1 @ summarize (d + 1) e2
adamc@456 346
adamc@579 347 | EClosure (_, es) => List.concat (map (summarize d) es)
adamc@470 348
adamc@579 349 | EQuery {query, body, initial, ...} =>
adamc@579 350 List.concat [summarize d query,
adamc@579 351 summarize (d + 2) body,
adamc@579 352 summarize d initial,
adamc@579 353 [ReadDb]]
adamc@470 354
adamc@579 355 | EDml e => summarize d e @ [WriteDb]
adamc@579 356 | ENextval e => summarize d e @ [WriteDb]
adamc@579 357 | EUnurlify (e, _) => summarize d e
adamc@579 358 | EJavaScript (_, e, _) => summarize d e
adamc@579 359 | ESignalReturn e => summarize d e
adamc@579 360 | ESignalBind (e1, e2) => summarize d e1 @ summarize d e2
adamc@579 361 | ESignalSource e => summarize d e
adamc@608 362
adamc@614 363 | EServerCall (e, ek, _) => summarize d e @ summarize d ek @ [Unsure]
adamc@670 364 | ERecv (e, ek, _) => summarize d e @ summarize d ek @ [Unsure]
adamc@695 365 | ESleep (e, ek) => summarize d e @ summarize d ek @ [Unsure]
adamc@579 366 in
adamc@579 367 (*Print.prefaces "Summarize"
adamc@579 368 [("e", MonoPrint.p_exp MonoEnv.empty (e, ErrorMsg.dummySpan)),
adamc@579 369 ("d", Print.PD.string (Int.toString d)),
adamc@579 370 ("s", p_events s)];*)
adamc@579 371 s
adamc@579 372 end
adamc@470 373
adamc@470 374 fun exp env e =
adamc@470 375 let
adamc@470 376 (*val () = Print.prefaces "exp" [("e", MonoPrint.p_exp env (e, ErrorMsg.dummySpan))]*)
adamc@470 377
adamc@470 378 val r =
adamc@470 379 case e of
adamc@470 380 ERel n =>
adamc@470 381 (case E.lookupERel env n of
adamc@470 382 (_, _, SOME e') => #1 e'
adamc@470 383 | _ => e)
adamc@470 384 | ENamed n =>
adamc@470 385 (case E.lookupENamed env n of
adamc@470 386 (_, _, SOME e', _) => ((*Print.prefaces "Switch" [("n", Print.PD.string (Int.toString n)),
adamc@470 387 ("e'", MonoPrint.p_exp env e')];*)
adamc@470 388 #1 e')
adamc@470 389 | _ => e)
adamc@470 390
adamc@470 391 | EApp ((EAbs (x, t, _, e1), loc), e2) =>
adamc@470 392 ((*Print.prefaces "Considering" [("e1", MonoPrint.p_exp (E.pushERel env x t NONE) e1),
adamc@694 393 ("e2", MonoPrint.p_exp env e2),
adamc@694 394 ("sub", MonoPrint.p_exp env (reduceExp env (subExpInExp (0, e2) e1)))];*)
adamc@470 395 if impure e2 then
adamc@470 396 #1 (reduceExp env (ELet (x, t, e2, e1), loc))
adamc@470 397 else
adamc@470 398 #1 (reduceExp env (subExpInExp (0, e2) e1)))
adamc@470 399
adamc@470 400 | ECase (e', pes, {disc, result}) =>
adamc@442 401 let
adamc@470 402 fun push () =
adamc@470 403 case result of
adamc@470 404 (TFun (dom, result), loc) =>
adamc@470 405 if List.all (fn (_, (EAbs _, _)) => true | _ => false) pes then
adamc@470 406 EAbs ("_", dom, result,
adamc@470 407 (ECase (liftExpInExp 0 e',
adamc@470 408 map (fn (p, (EAbs (_, _, _, e), _)) =>
adamc@470 409 (p, swapExpVarsPat (0, patBinds p) e)
adamc@470 410 | _ => raise Fail "MonoReduce ECase") pes,
adamc@470 411 {disc = disc, result = result}), loc))
adamc@470 412 else
adamc@470 413 e
adamc@470 414 | _ => e
adamc@318 415
adamc@470 416 fun search pes =
adamc@470 417 case pes of
adamc@470 418 [] => push ()
adamc@470 419 | (p, body) :: pes =>
adamc@470 420 case match (env, p, e') of
adamc@470 421 No => search pes
adamc@470 422 | Maybe => push ()
adamc@470 423 | Yes env => #1 (reduceExp env body)
adamc@470 424 in
adamc@470 425 search pes
adamc@470 426 end
adamc@318 427
adamc@470 428 | EField ((ERecord xes, _), x) =>
adamc@470 429 (case List.find (fn (x', _, _) => x' = x) xes of
adamc@470 430 SOME (_, e, _) => #1 e
adamc@470 431 | NONE => e)
adamc@398 432
adamc@470 433 | ELet (x1, t1, (ELet (x2, t2, e1, b1), loc), b2) =>
adamc@470 434 let
adamc@470 435 val e' = (ELet (x2, t2, e1,
adamc@470 436 (ELet (x1, t1, b1,
adamc@470 437 liftExpInExp 1 b2), loc)), loc)
adamc@442 438 in
adamc@470 439 (*Print.prefaces "ELet commute" [("e", MonoPrint.p_exp env (e, loc)),
adamc@470 440 ("e'", MonoPrint.p_exp env e')];*)
adamc@470 441 #1 (reduceExp env e')
adamc@470 442 end
adamc@470 443 | EApp ((ELet (x, t, e, b), loc), e') =>
adamc@470 444 #1 (reduceExp env (ELet (x, t, e,
adamc@470 445 (EApp (b, liftExpInExp 0 e'), loc)), loc))
adamc@470 446
adamc@470 447 | ELet (x, t, e', (EAbs (x', t' as (TRecord [], _), ran, e''), loc)) =>
adamc@470 448 (*if impure e' then
adamc@470 449 e
adamc@470 450 else*)
adamc@470 451 (* Seems unsound in general without the check... should revisit later *)
adamc@470 452 EAbs (x', t', ran, (ELet (x, t, liftExpInExp 0 e', swapExpVars 0 e''), loc))
adamc@470 453
adamc@470 454 | ELet (x, t, e', b) =>
adamc@470 455 let
adamc@470 456 fun doSub () =
adamc@470 457 #1 (reduceExp env (subExpInExp (0, e') b))
adamc@470 458
adamc@470 459 fun trySub () =
adamc@470 460 case t of
adamc@470 461 (TFfi ("Basis", "string"), _) => doSub ()
adamc@568 462 | (TSignal _, _) => e
adamc@470 463 | _ =>
adamc@470 464 case e' of
adamc@470 465 (ECase _, _) => e
adamc@470 466 | _ => doSub ()
adamc@470 467 in
adamc@470 468 if impure e' then
adamc@470 469 let
adamc@470 470 val effs_e' = summarize 0 e'
adamc@489 471 val effs_e' = List.filter (fn x => x <> UseRel) effs_e'
adamc@470 472 val effs_b = summarize 0 b
adamc@470 473
adamc@470 474 (*val () = Print.prefaces "Try"
adamc@489 475 [("e", MonoPrint.p_exp env (e, ErrorMsg.dummySpan)),
adamc@489 476 ("e'", p_events effs_e'),
adamc@489 477 ("b", p_events effs_b)]*)
adamc@470 478
adamc@470 479 fun does eff = List.exists (fn eff' => eff' = eff) effs_e'
adamc@470 480 val writesPage = does WritePage
adamc@470 481 val readsDb = does ReadDb
adamc@470 482 val writesDb = does WriteDb
adamc@470 483
adamc@470 484 fun verifyUnused eff =
adamc@470 485 case eff of
adamc@481 486 UseRel => false
adamc@470 487 | _ => true
adamc@470 488
adamc@470 489 fun verifyCompatible effs =
adamc@470 490 case effs of
adamc@470 491 [] => false
adamc@470 492 | eff :: effs =>
adamc@470 493 case eff of
adamc@470 494 Unsure => false
adamc@481 495 | UseRel => List.all verifyUnused effs
adamc@470 496 | WritePage => not writesPage andalso verifyCompatible effs
adamc@470 497 | ReadDb => not writesDb andalso verifyCompatible effs
adamc@470 498 | WriteDb => not writesDb andalso not readsDb andalso verifyCompatible effs
adamc@470 499 in
adamc@470 500 (*Print.prefaces "verifyCompatible"
adamc@601 501 [("e'", MonoPrint.p_exp env e'),
adamc@601 502 ("b", MonoPrint.p_exp (E.pushERel env x t NONE) b),
adamc@601 503 ("effs_e'", Print.p_list p_event effs_e'),
adamc@601 504 ("effs_b", Print.p_list p_event effs_b)];*)
adamc@601 505 if List.null effs_e' orelse (List.all (fn eff => eff <> Unsure) effs_e'
adamc@601 506 andalso verifyCompatible effs_b) then
adamc@470 507 trySub ()
adamc@470 508 else
adamc@470 509 e
adamc@470 510 end
adamc@470 511 else
adamc@442 512 trySub ()
adamc@442 513 end
adamc@252 514
adamc@470 515 | EStrcat ((EPrim (Prim.String s1), _), (EPrim (Prim.String s2), _)) =>
adamc@470 516 EPrim (Prim.String (s1 ^ s2))
adamc@268 517
adamc@572 518 | ESignalBind ((ESignalReturn e1, loc), e2) =>
adamc@572 519 #1 (reduceExp env (EApp (e2, e1), loc))
adamc@572 520
adamc@470 521 | _ => e
adamc@470 522 in
adamc@470 523 (*Print.prefaces "exp'" [("r", MonoPrint.p_exp env (r, ErrorMsg.dummySpan))];*)
adamc@470 524 r
adamc@470 525 end
adamc@470 526
adamc@470 527 and bind (env, b) =
adamc@470 528 case b of
adamc@470 529 U.Decl.Datatype (x, n, xncs) => E.pushDatatype env x n xncs
adamc@470 530 | U.Decl.RelE (x, t) => E.pushERel env x t NONE
adamc@470 531 | U.Decl.NamedE (x, n, t, eo, s) => E.pushENamed env x n t (Option.map (reduceExp env) eo) s
adamc@470 532
adamc@470 533 and reduceExp env = U.Exp.mapB {typ = typ, exp = exp, bind = bind} env
adamc@470 534
adamc@470 535 fun decl env d = d
adamc@398 536 in
adamc@470 537 U.File.mapB {typ = typ, exp = exp, decl = decl, bind = bind} E.empty file
adamc@398 538 end
adamc@133 539
adamc@133 540 end