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annotate src/unpoly.sml @ 325:e457d8972ff1

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author Adam Chlipala <adamc@hcoop.net>
date Thu, 11 Sep 2008 17:41:52 -0400
parents 04ebfe929a98
children 2d64457eedb1
rev   line source
adamc@315 1 (* Copyright (c) 2008, Adam Chlipala
adamc@315 2 * All rights reserved.
adamc@315 3 *
adamc@315 4 * Redistribution and use in source and binary forms, with or without
adamc@315 5 * modification, are permitted provided that the following conditions are met:
adamc@315 6 *
adamc@315 7 * - Redistributions of source code must retain the above copyright notice,
adamc@315 8 * this list of conditions and the following disclaimer.
adamc@315 9 * - Redistributions in binary form must reproduce the above copyright notice,
adamc@315 10 * this list of conditions and the following disclaimer in the documentation
adamc@315 11 * and/or other materials provided with the distribution.
adamc@315 12 * - The names of contributors may not be used to endorse or promote products
adamc@315 13 * derived from this software without specific prior written permission.
adamc@315 14 *
adamc@315 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
adamc@315 16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
adamc@315 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
adamc@315 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
adamc@315 19 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
adamc@315 20 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
adamc@315 21 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
adamc@315 22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
adamc@315 23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
adamc@315 24 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
adamc@315 25 * POSSIBILITY OF SUCH DAMAGE.
adamc@315 26 *)
adamc@315 27
adamc@315 28 (* Simplify a Core program by repeating polymorphic function definitions *)
adamc@315 29
adamc@315 30 structure Unpoly :> UNPOLY = struct
adamc@315 31
adamc@315 32 open Core
adamc@315 33
adamc@315 34 structure E = CoreEnv
adamc@315 35 structure U = CoreUtil
adamc@315 36
adamc@315 37 structure IS = IntBinarySet
adamc@315 38 structure IM = IntBinaryMap
adamc@315 39
adamc@315 40
adamc@315 41 (** The actual specialization *)
adamc@315 42
adamc@315 43 val liftConInCon = E.liftConInCon
adamc@315 44 val subConInCon = E.subConInCon
adamc@315 45
adamc@315 46 val liftConInExp = E.liftConInExp
adamc@315 47 val subConInExp = E.subConInExp
adamc@315 48
adamc@316 49 fun unpolyNamed (xn, rep) =
adamc@316 50 U.Exp.map {kind = fn k => k,
adamc@316 51 con = fn c => c,
adamc@316 52 exp = fn e =>
adamc@316 53 case e of
adamc@316 54 ENamed xn' =>
adamc@316 55 if xn' = xn then
adamc@316 56 rep
adamc@316 57 else
adamc@316 58 e
adamc@325 59 | ECApp (e', _) =>
adamc@325 60 let
adamc@325 61 fun isTheOne (e, _) =
adamc@325 62 case e of
adamc@325 63 ENamed xn' => xn' = xn
adamc@325 64 | ECApp (e, _) => isTheOne e
adamc@325 65 | _ => false
adamc@325 66 in
adamc@325 67 if isTheOne e' then
adamc@325 68 #1 e'
adamc@325 69 else
adamc@325 70 e
adamc@325 71 end
adamc@316 72 | _ => e}
adamc@316 73
adamc@315 74 type state = {
adamc@315 75 funcs : (kind list * (string * int * con * exp * string) list) IM.map,
adamc@315 76 decls : decl list,
adamc@315 77 nextName : int
adamc@315 78 }
adamc@315 79
adamc@315 80 fun kind (k, st) = (k, st)
adamc@315 81
adamc@315 82 fun con (c, st) = (c, st)
adamc@315 83
adamc@315 84 fun exp (e, st : state) =
adamc@315 85 case e of
adamc@315 86 ECApp _ =>
adamc@315 87 let
adamc@315 88 (*val () = Print.prefaces "exp" [("e", CorePrint.p_exp CoreEnv.empty (e, ErrorMsg.dummySpan))]*)
adamc@315 89
adamc@315 90 fun unravel (e, cargs) =
adamc@315 91 case e of
adamc@315 92 ECApp ((e, _), c) => unravel (e, c :: cargs)
adamc@315 93 | ENamed n => SOME (n, rev cargs)
adamc@315 94 | _ => NONE
adamc@315 95 in
adamc@315 96 case unravel (e, []) of
adamc@315 97 NONE => (e, st)
adamc@315 98 | SOME (n, cargs) =>
adamc@315 99 case IM.find (#funcs st, n) of
adamc@315 100 NONE => (e, st)
adamc@315 101 | SOME (ks, vis) =>
adamc@315 102 let
adamc@315 103 val (vis, nextName) = ListUtil.foldlMap
adamc@315 104 (fn ((x, n, t, e, s), nextName) =>
adamc@315 105 ((x, nextName, n, t, e, s), nextName + 1))
adamc@315 106 (#nextName st) vis
adamc@315 107
adamc@315 108 fun specialize (x, n, n_old, t, e, s) =
adamc@315 109 let
adamc@315 110 fun trim (t, e, cargs) =
adamc@315 111 case (t, e, cargs) of
adamc@315 112 ((TCFun (_, _, t), _),
adamc@315 113 (ECAbs (_, _, e), _),
adamc@315 114 carg :: cargs) =>
adamc@315 115 let
adamc@315 116 val t = subConInCon (length cargs, carg) t
adamc@315 117 val e = subConInExp (length cargs, carg) e
adamc@315 118 in
adamc@315 119 trim (t, e, cargs)
adamc@315 120 end
adamc@316 121 | (_, _, []) =>
adamc@316 122 let
adamc@316 123 val e = foldl (fn ((_, n, n_old, _, _, _), e) =>
adamc@316 124 unpolyNamed (n_old, ENamed n) e)
adamc@325 125 e vis
adamc@316 126 in
adamc@316 127 SOME (t, e)
adamc@316 128 end
adamc@315 129 | _ => NONE
adamc@315 130 in
adamc@315 131 (*Print.prefaces "specialize"
adamc@315 132 [("t", CorePrint.p_con CoreEnv.empty t),
adamc@315 133 ("e", CorePrint.p_exp CoreEnv.empty e),
adamc@315 134 ("|cargs|", Print.PD.string (Int.toString (length cargs)))];*)
adamc@315 135 Option.map (fn (t, e) => (x, n, n_old, t, e, s))
adamc@315 136 (trim (t, e, cargs))
adamc@315 137 end
adamc@315 138
adamc@315 139 val vis = List.map specialize vis
adamc@315 140 in
adamc@316 141 if List.exists (not o Option.isSome) vis orelse length cargs > length ks then
adamc@315 142 (e, st)
adamc@315 143 else
adamc@315 144 let
adamc@315 145 val vis = List.mapPartial (fn x => x) vis
adamc@316 146 val vis = map (fn (x, n, n_old, t, e, s) =>
adamc@316 147 (x ^ "_unpoly", n, n_old, t, e, s)) vis
adamc@315 148 val vis' = map (fn (x, n, _, t, e, s) =>
adamc@316 149 (x, n, t, e, s)) vis
adamc@316 150
adamc@316 151 val ks' = List.drop (ks, length cargs)
adamc@315 152 in
adamc@315 153 case List.find (fn (_, _, n_old, _, _, _) => n_old = n) vis of
adamc@315 154 NONE => raise Fail "Unpoly: Inconsistent 'val rec' record"
adamc@315 155 | SOME (_, n, _, _, _, _) =>
adamc@315 156 (ENamed n,
adamc@316 157 {funcs = foldl (fn (vi, funcs) =>
adamc@316 158 IM.insert (funcs, #2 vi, (ks', vis')))
adamc@316 159 (#funcs st) vis',
adamc@315 160 decls = (DValRec vis', ErrorMsg.dummySpan) :: #decls st,
adamc@315 161 nextName = nextName})
adamc@315 162 end
adamc@315 163 end
adamc@315 164 end
adamc@315 165 | _ => (e, st)
adamc@315 166
adamc@315 167 fun decl (d, st : state) =
adamc@315 168 case d of
adamc@315 169 DValRec (vis as ((x, n, t, e, s) :: rest)) =>
adamc@315 170 let
adamc@315 171 fun unravel (e, cargs) =
adamc@315 172 case e of
adamc@315 173 (ECAbs (_, k, e), _) =>
adamc@315 174 unravel (e, k :: cargs)
adamc@315 175 | _ => rev cargs
adamc@315 176
adamc@315 177 val cargs = unravel (e, [])
adamc@315 178
adamc@315 179 fun unravel (e, cargs) =
adamc@315 180 case (e, cargs) of
adamc@315 181 ((ECAbs (_, k, e), _), k' :: cargs) =>
adamc@315 182 U.Kind.compare (k, k') = EQUAL
adamc@315 183 andalso unravel (e, cargs)
adamc@315 184 | (_, []) => true
adamc@315 185 | _ => false
adamc@315 186 in
adamc@315 187 if List.exists (fn vi => not (unravel (#4 vi, cargs))) rest then
adamc@315 188 (d, st)
adamc@315 189 else
adamc@315 190 let
adamc@315 191 val ns = IS.addList (IS.empty, map #2 vis)
adamc@315 192 val nargs = length cargs
adamc@315 193
adamc@315 194 fun deAbs (e, cargs) =
adamc@315 195 case (e, cargs) of
adamc@315 196 ((ECAbs (_, _, e), _), _ :: cargs) => deAbs (e, cargs)
adamc@315 197 | (_, []) => e
adamc@315 198 | _ => raise Fail "Unpoly: deAbs"
adamc@315 199
adamc@315 200 (** Verifying lack of polymorphic recursion *)
adamc@315 201
adamc@315 202 fun kind _ = false
adamc@315 203 fun con _ = false
adamc@315 204
adamc@315 205 fun exp e =
adamc@315 206 case e of
adamc@315 207 ECApp (e, c) =>
adamc@315 208 let
adamc@315 209 fun isIrregular (e, pos) =
adamc@315 210 case #1 e of
adamc@315 211 ENamed n =>
adamc@315 212 IS.member (ns, n)
adamc@315 213 andalso
adamc@315 214 (case #1 c of
adamc@315 215 CRel i => i <> nargs - pos
adamc@315 216 | _ => true)
adamc@315 217 | ECApp (e, _) => isIrregular (e, pos + 1)
adamc@315 218 | _ => false
adamc@315 219 in
adamc@315 220 isIrregular (e, 1)
adamc@315 221 end
adamc@315 222 | ECAbs _ => true
adamc@315 223 | _ => false
adamc@315 224
adamc@315 225 val irregular = U.Exp.exists {kind = kind, con = con, exp = exp}
adamc@315 226 in
adamc@315 227 if List.exists (fn x => irregular (deAbs (#4 x, cargs))) vis then
adamc@315 228 (d, st)
adamc@315 229 else
adamc@315 230 (d, {funcs = foldl (fn (vi, funcs) =>
adamc@315 231 IM.insert (funcs, #2 vi, (cargs, vis)))
adamc@315 232 (#funcs st) vis,
adamc@315 233 decls = #decls st,
adamc@315 234 nextName = #nextName st})
adamc@315 235 end
adamc@315 236 end
adamc@315 237
adamc@315 238 | _ => (d, st)
adamc@315 239
adamc@315 240 val polyDecl = U.Decl.foldMap {kind = kind, con = con, exp = exp, decl = decl}
adamc@315 241
adamc@315 242 fun unpoly file =
adamc@315 243 let
adamc@315 244 fun doDecl (d : decl, st : state) =
adamc@315 245 let
adamc@315 246 val (d, st) = polyDecl st d
adamc@315 247 in
adamc@315 248 (rev (d :: #decls st),
adamc@315 249 {funcs = #funcs st,
adamc@315 250 decls = [],
adamc@315 251 nextName = #nextName st})
adamc@315 252 end
adamc@315 253
adamc@315 254 val (ds, _) = ListUtil.foldlMapConcat doDecl
adamc@315 255 {funcs = IM.empty,
adamc@315 256 decls = [],
adamc@315 257 nextName = U.File.maxName file + 1} file
adamc@315 258 in
adamc@315 259 ds
adamc@315 260 end
adamc@315 261
adamc@315 262 end