Mercurial > urweb
view src/reduce.sml @ 842:d1b6acaec265
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author | Adam Chlipala <adamc@hcoop.net> |
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date | Sun, 07 Jun 2009 12:01:55 -0400 |
parents | 669ac5e9a69e |
children | ed06e25c70ef |
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(* Copyright (c) 2008, Adam Chlipala * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * - Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * - Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * - The names of contributors may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. *) (* Simplify a Core program algebraically *) structure Reduce :> REDUCE = struct open Core structure IM = IntBinaryMap datatype env_item = UnknownK | KnownK of kind | UnknownC | KnownC of con | UnknownE | KnownE of exp | Lift of int * int * int type env = env_item list fun ei2s ei = case ei of UnknownK => "UK" | KnownK _ => "KK" | UnknownC => "UC" | KnownC _ => "KC" | UnknownE => "UE" | KnownE _ => "KE" | Lift (_, n1, n2) => "(" ^ Int.toString n1 ^ ", " ^ Int.toString n2 ^ ")" fun e2s env = String.concatWith " " (map ei2s env) val deKnown = List.filter (fn KnownC _ => false | KnownE _ => false | KnownK _ => false | _ => true) fun kindConAndExp (namedC, namedE) = let fun kind env (all as (k, loc)) = case k of KType => all | KArrow (k1, k2) => (KArrow (kind env k1, kind env k2), loc) | KName => all | KRecord k => (KRecord (kind env k), loc) | KUnit => all | KTuple ks => (KTuple (map (kind env) ks), loc) | KRel n => let fun find (n', env, nudge, lift) = case env of [] => raise Fail "Reduce.kind: KRel" | UnknownC :: rest => find (n', rest, nudge, lift) | KnownC _ :: rest => find (n', rest, nudge, lift) | UnknownE :: rest => find (n', rest, nudge, lift) | KnownE _ :: rest => find (n', rest, nudge, lift) | Lift (lift', _, _) :: rest => find (n', rest, nudge + lift', lift + lift') | UnknownK :: rest => if n' = 0 then (KRel (n + nudge), loc) else find (n' - 1, rest, nudge, lift + 1) | KnownK k :: rest => if n' = 0 then kind (Lift (lift, 0, 0) :: rest) k else find (n' - 1, rest, nudge - 1, lift) in find (n, env, 0, 0) end | KFun (x, k) => (KFun (x, kind (UnknownK :: env) k), loc) fun con env (all as (c, loc)) = ((*Print.prefaces "con" [("c", CorePrint.p_con CoreEnv.empty all)];*) case c of TFun (c1, c2) => (TFun (con env c1, con env c2), loc) | TCFun (x, k, c2) => (TCFun (x, kind env k, con (UnknownC :: env) c2), loc) | TKFun (x, c2) => (TKFun (x, con (UnknownK :: env) c2), loc) | TRecord c => (TRecord (con env c), loc) | CRel n => let fun find (n', env, nudge, liftK, liftC) = case env of [] => raise Fail "Reduce.con: CRel" | UnknownK :: rest => find (n', rest, nudge, liftK + 1, liftC) | KnownK _ :: rest => find (n', rest, nudge, liftK, liftC) | UnknownE :: rest => find (n', rest, nudge, liftK, liftC) | KnownE _ :: rest => find (n', rest, nudge, liftK, liftC) | Lift (liftK', liftC', _) :: rest => find (n', rest, nudge + liftC', liftK + liftK', liftC + liftC') | UnknownC :: rest => if n' = 0 then (CRel (n + nudge), loc) else find (n' - 1, rest, nudge, liftK, liftC + 1) | KnownC c :: rest => if n' = 0 then con (Lift (liftK, liftC, 0) :: rest) c else find (n' - 1, rest, nudge - 1, liftK, liftC) in (*print (Int.toString n ^ ": " ^ e2s env ^ "\n");*) find (n, env, 0, 0, 0) end | CNamed n => (case IM.find (namedC, n) of NONE => all | SOME c => c) | CFfi _ => all | CApp (c1, c2) => let val c1 = con env c1 val c2 = con env c2 in case #1 c1 of CAbs (_, _, b) => con (KnownC c2 :: deKnown env) b | CApp ((CMap (dom, ran), _), f) => (case #1 c2 of CRecord (_, []) => (CRecord (kind env ran, []), loc) | CRecord (_, (x, c) :: rest) => con (deKnown env) (CConcat ((CRecord (ran, [(x, (CApp (f, c), loc))]), loc), (CApp (c1, (CRecord (kind env dom, rest), loc)), loc)), loc) | _ => (CApp (c1, c2), loc)) | _ => (CApp (c1, c2), loc) end | CAbs (x, k, b) => (CAbs (x, kind env k, con (UnknownC :: env) b), loc) | CKApp (c1, k) => let val c1 = con env c1 in case #1 c1 of CKAbs (_, b) => con (KnownK k :: deKnown env) b | _ => (CKApp (c1, kind env k), loc) end | CKAbs (x, b) => (CKAbs (x, con (UnknownK :: env) b), loc) | CName _ => all | CRecord (k, xcs) => (CRecord (kind env k, map (fn (x, c) => (con env x, con env c)) xcs), loc) | CConcat (c1, c2) => let val c1 = con env c1 val c2 = con env c2 in case (#1 c1, #1 c2) of (CRecord (k, xcs1), CRecord (_, xcs2)) => (CRecord (kind env k, xcs1 @ xcs2), loc) | _ => (CConcat (c1, c2), loc) end | CMap (dom, ran) => (CMap (kind env dom, kind env ran), loc) | CUnit => all | CTuple cs => (CTuple (map (con env) cs), loc) | CProj (c, n) => let val c = con env c in case #1 c of CTuple cs => List.nth (cs, n - 1) | _ => (CProj (c, n), loc) end) fun patCon pc = case pc of PConVar _ => pc | PConFfi {mod = m, datatyp, params, con = c, arg, kind} => PConFfi {mod = m, datatyp = datatyp, params = params, con = c, arg = Option.map (con (map (fn _ => UnknownC) params)) arg, kind = kind} val k = (KType, ErrorMsg.dummySpan) fun doPart e (this as (x, t), rest) = ((x, (EField (e, x, {field = t, rest = (CRecord (k, rest), #2 t)}), #2 t), t), this :: rest) fun exp env (all as (e, loc)) = ((*Print.prefaces "exp" [("e", CorePrint.p_exp CoreEnv.empty all), ("env", Print.PD.string (e2s env))];*) case e of EPrim _ => all | ERel n => let fun find (n', env, nudge, liftK, liftC, liftE) = case env of [] => raise Fail "Reduce.exp: ERel" | UnknownK :: rest => find (n', rest, nudge, liftK + 1, liftC, liftE) | KnownK _ :: rest => find (n', rest, nudge, liftK, liftC, liftE) | UnknownC :: rest => find (n', rest, nudge, liftK, liftC + 1, liftE) | KnownC _ :: rest => find (n', rest, nudge, liftK, liftC, liftE) | Lift (liftK', liftC', liftE') :: rest => find (n', rest, nudge + liftE', liftK + liftK', liftC + liftC', liftE + liftE') | UnknownE :: rest => if n' = 0 then (ERel (n + nudge), loc) else find (n' - 1, rest, nudge, liftK, liftC, liftE + 1) | KnownE e :: rest => if n' = 0 then ((*print "SUBSTITUTING\n";*) exp (Lift (liftK, liftC, liftE) :: rest) e) else find (n' - 1, rest, nudge - 1, liftK, liftC, liftE) in (*print (Int.toString n ^ ": " ^ e2s env ^ "\n");*) find (n, env, 0, 0, 0, 0) end | ENamed n => (case IM.find (namedE, n) of NONE => all | SOME e => e) | ECon (dk, pc, cs, eo) => (ECon (dk, patCon pc, map (con env) cs, Option.map (exp env) eo), loc) | EFfi _ => all | EFfiApp (m, f, es) => (EFfiApp (m, f, map (exp env) es), loc) | EApp (e1, e2) => let val e1 = exp env e1 val e2 = exp env e2 in case #1 e1 of EAbs (_, _, _, b) => exp (KnownE e2 :: deKnown env) b | _ => (EApp (e1, e2), loc) end | EAbs (x, dom, ran, e) => (EAbs (x, con env dom, con env ran, exp (UnknownE :: env) e), loc) | ECApp (e, c) => let val e = exp env e val c = con env c in case #1 e of ECAbs (_, _, b) => exp (KnownC c :: deKnown env) b | _ => (ECApp (e, c), loc) end | ECAbs (x, k, e) => (ECAbs (x, kind env k, exp (UnknownC :: env) e), loc) | EKApp (e, k) => let val e = exp env e in case #1 e of EKAbs (_, b) => exp (KnownK k :: deKnown env) b | _ => (EKApp (e, kind env k), loc) end | EKAbs (x, e) => (EKAbs (x, exp (UnknownK :: env) e), loc) | ERecord xcs => (ERecord (map (fn (x, e, t) => (con env x, exp env e, con env t)) xcs), loc) | EField (e, c, {field, rest}) => let val e = exp env e val c = con env c fun default () = (EField (e, c, {field = con env field, rest = con env rest}), loc) in case (#1 e, #1 c) of (ERecord xcs, CName x) => (case List.find (fn ((CName x', _), _, _) => x' = x | _ => false) xcs of NONE => default () | SOME (_, e, _) => e) | _ => default () end | EConcat (e1, c1, e2, c2) => let val e1 = exp env e1 val e2 = exp env e2 in case (#1 e1, #1 e2) of (ERecord xes1, ERecord xes2) => (ERecord (xes1 @ xes2), loc) | _ => let val c1 = con env c1 val c2 = con env c2 in case (#1 c1, #1 c2) of (CRecord (k, xcs1), CRecord (_, xcs2)) => let val (xes1, rest) = ListUtil.foldlMap (doPart e1) [] xcs1 val (xes2, _) = ListUtil.foldlMap (doPart e2) rest xcs2 in exp (deKnown env) (ERecord (xes1 @ xes2), loc) end | _ => (EConcat (e1, c1, e2, c2), loc) end end | ECut (e, c, {field, rest}) => let val e = exp env e val c = con env c fun default () = let val rest = con env rest in case #1 rest of CRecord (k, xcs) => let val (xes, _) = ListUtil.foldlMap (doPart e) [] xcs in exp (deKnown env) (ERecord xes, loc) end | _ => (ECut (e, c, {field = con env field, rest = rest}), loc) end in case (#1 e, #1 c) of (ERecord xes, CName x) => if List.all (fn ((CName _, _), _, _) => true | _ => false) xes then (ERecord (List.filter (fn ((CName x', _), _, _) => x' <> x | _ => raise Fail "Reduce: ECut") xes), loc) else default () | _ => default () end | ECutMulti (e, c, {rest}) => let val e = exp env e val c = con env c fun default () = let val rest = con env rest in case #1 rest of CRecord (k, xcs) => let val (xes, _) = ListUtil.foldlMap (doPart e) [] xcs in exp (deKnown env) (ERecord xes, loc) end | _ => (ECutMulti (e, c, {rest = rest}), loc) end in case (#1 e, #1 c) of (ERecord xes, CRecord (_, xcs)) => if List.all (fn ((CName _, _), _, _) => true | _ => false) xes andalso List.all (fn ((CName _, _), _) => true | _ => false) xcs then (ERecord (List.filter (fn ((CName x', _), _, _) => List.all (fn ((CName x, _), _) => x' <> x | _ => raise Fail "Reduce: ECutMulti [1]") xcs | _ => raise Fail "Reduce: ECutMulti [2]") xes), loc) else default () | _ => default () end | ECase (_, [((PRecord [], _), e)], _) => exp env e | ECase (_, [((PWild, _), e)], _) => exp env e | ECase (e, pes, {disc, result}) => let fun patBinds (p, _) = case p of PWild => 0 | PVar _ => 1 | PPrim _ => 0 | PCon (_, _, _, NONE) => 0 | PCon (_, _, _, SOME p) => patBinds p | PRecord xpts => foldl (fn ((_, p, _), n) => n + patBinds p) 0 xpts fun pat (all as (p, loc)) = case p of PWild => all | PVar (x, t) => (PVar (x, con env t), loc) | PPrim _ => all | PCon (dk, pc, cs, po) => (PCon (dk, patCon pc, map (con env) cs, Option.map pat po), loc) | PRecord xpts => (PRecord (map (fn (x, p, t) => (x, pat p, con env t)) xpts), loc) in (ECase (exp env e, map (fn (p, e) => (pat p, exp (List.tabulate (patBinds p, fn _ => UnknownE) @ env) e)) pes, {disc = con env disc, result = con env result}), loc) end | EWrite e => (EWrite (exp env e), loc) | EClosure (n, es) => (EClosure (n, map (exp env) es), loc) | ELet (x, t, e1, e2) => (ELet (x, con env t, exp env e1, exp (UnknownE :: env) e2), loc) | EServerCall (n, es, e, t) => (EServerCall (n, map (exp env) es, exp env e, con env t), loc)) in {kind = kind, con = con, exp = exp} end fun kind namedC env k = #kind (kindConAndExp (namedC, IM.empty)) env k fun con namedC env c = #con (kindConAndExp (namedC, IM.empty)) env c fun exp (namedC, namedE) env e = #exp (kindConAndExp (namedC, namedE)) env e fun reduce file = let fun doDecl (d as (_, loc), st as (namedC, namedE)) = case #1 d of DCon (x, n, k, c) => let val k = kind namedC [] k val c = con namedC [] c in ((DCon (x, n, k, c), loc), (IM.insert (namedC, n, c), namedE)) end | DDatatype dts => ((DDatatype (map (fn (x, n, ps, cs) => let val env = map (fn _ => UnknownC) ps in (x, n, ps, map (fn (x, n, co) => (x, n, Option.map (con namedC env) co)) cs) end) dts), loc), st) | DVal (x, n, t, e, s) => let val t = con namedC [] t val e = exp (namedC, namedE) [] e in ((DVal (x, n, t, e, s), loc), (namedC, IM.insert (namedE, n, e))) end | DValRec vis => ((DValRec (map (fn (x, n, t, e, s) => (x, n, con namedC [] t, exp (namedC, namedE) [] e, s)) vis), loc), st) | DExport _ => (d, st) | DTable (s, n, c, s', pe, pc, ce, cc) => ((DTable (s, n, con namedC [] c, s', exp (namedC, namedE) [] pe, con namedC [] pc, exp (namedC, namedE) [] ce, con namedC [] cc), loc), st) | DSequence _ => (d, st) | DView (s, n, s', e, c) => ((DView (s, n, s', exp (namedC, namedE) [] e, con namedC [] c), loc), st) | DDatabase _ => (d, st) | DCookie (s, n, c, s') => ((DCookie (s, n, con namedC [] c, s'), loc), st) | DStyle (s, n, s') => ((DStyle (s, n, s'), loc), st) val (file, _) = ListUtil.foldlMap doDecl (IM.empty, IM.empty) file in file end end