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   1 /*
   2  * Copyright © 2016 Keith Packard <keithp@keithp.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  */
  14
  15 #include "ao_scheme.h"
  16
  17 static void cons_mark(void *addr)
  18 {
  19         struct ao_scheme_cons   *cons = addr;
  20
  21         for (;;) {
  22                 ao_poly cdr = cons->cdr;
  23
  24                 ao_scheme_poly_mark(cons->car, 1);
  25                 if (!cdr)
  26                         break;
  27                 if (!ao_scheme_is_cons(cdr)) {
  28                         ao_scheme_poly_mark(cdr, 0);
  29                         break;
  30                 }
  31                 cons = ao_scheme_poly_cons(cdr);
  32                 if (ao_scheme_mark_memory(&ao_scheme_cons_type, cons))
  33                         break;
  34         }
  35 }
  36
  37 static int cons_size(void *addr)
  38 {
  39         (void) addr;
  40         return sizeof (struct ao_scheme_cons);
  41 }
  42
  43 static void cons_move(void *addr)
  44 {
  45         struct ao_scheme_cons   *cons = addr;
  46
  47         if (!cons)
  48                 return;
  49
  50         for (;;) {
  51                 ao_poly                 cdr;
  52                 struct ao_scheme_cons   *c;
  53                 int     ret;
  54
  55                 MDBG_MOVE("cons_move start %d (%d, %d)\n",
  56                           MDBG_OFFSET(cons), MDBG_OFFSET(ao_scheme_ref(cons->car)), MDBG_OFFSET(ao_scheme_ref(cons->cdr)));
  57                 (void) ao_scheme_poly_move(&cons->car, 1);
  58                 cdr = cons->cdr;
  59                 if (!cdr)
  60                         break;
  61                 if (!ao_scheme_is_cons(cdr)) {
  62                         (void) ao_scheme_poly_move(&cons->cdr, 0);
  63                         break;
  64                 }
  65                 c = ao_scheme_poly_cons(cdr);
  66                 ret = ao_scheme_move_memory(&ao_scheme_cons_type, (void **) &c);
  67                 if (c != ao_scheme_poly_cons(cons->cdr))
  68                         cons->cdr = ao_scheme_cons_poly(c);
  69                 MDBG_MOVE("cons_move end %d (%d, %d)\n",
  70                           MDBG_OFFSET(cons), MDBG_OFFSET(ao_scheme_ref(cons->car)), MDBG_OFFSET(ao_scheme_ref(cons->cdr)));
  71                 if (ret)
  72                         break;
  73                 cons = c;
  74         }
  75 }
  76
  77 const struct ao_scheme_type ao_scheme_cons_type = {
  78         .mark = cons_mark,
  79         .size = cons_size,
  80         .move = cons_move,
  81         .name = "cons",
  82 };
  83
  84 struct ao_scheme_cons *ao_scheme_cons_free_list;
  85
  86 struct ao_scheme_cons *
  87 ao_scheme_cons_cons(ao_poly car, ao_poly cdr)
  88 {
  89         struct ao_scheme_cons   *cons;
  90
  91         if (ao_scheme_cons_free_list) {
  92                 cons = ao_scheme_cons_free_list;
  93                 ao_scheme_cons_free_list = ao_scheme_poly_cons(cons->cdr);
  94         } else {
  95                 ao_scheme_poly_stash(car);
  96                 ao_scheme_poly_stash(cdr);
  97                 cons = ao_scheme_alloc(sizeof (struct ao_scheme_cons));
  98                 cdr = ao_scheme_poly_fetch();
  99                 car = ao_scheme_poly_fetch();
 100                 if (!cons)
 101                         return NULL;
 102         }
 103         cons->car = car;
 104         cons->cdr = cdr;
 105         return cons;
 106 }
 107
 108 struct ao_scheme_cons *
 109 ao_scheme_cons_cdr(struct ao_scheme_cons *cons)
 110 {
 111         ao_poly cdr = cons->cdr;
 112         if (cdr == AO_SCHEME_NIL)
 113                 return NULL;
 114         if (!ao_scheme_is_cons(cdr)) {
 115                 (void) ao_scheme_error(AO_SCHEME_INVALID, "improper cdr %v", cdr);
 116                 return NULL;
 117         }
 118         return ao_scheme_poly_cons(cdr);
 119 }
 120
 121 ao_poly
 122 ao_scheme_cons(ao_poly car, ao_poly cdr)
 123 {
 124         return ao_scheme_cons_poly(ao_scheme_cons_cons(car, cdr));
 125 }
 126
 127 static struct ao_scheme_cons *
 128 ao_scheme_cons_copy(struct ao_scheme_cons *cons)
 129 {
 130         struct ao_scheme_cons   *head = NULL;
 131         struct ao_scheme_cons   *tail = NULL;
 132
 133         while (cons) {
 134                 struct ao_scheme_cons   *new;
 135                 ao_poly cdr;
 136
 137                 ao_scheme_cons_stash(cons);
 138                 ao_scheme_cons_stash(head);
 139                 ao_scheme_cons_stash(tail);
 140                 new = ao_scheme_alloc(sizeof (struct ao_scheme_cons));
 141                 tail = ao_scheme_cons_fetch();
 142                 head = ao_scheme_cons_fetch();
 143                 cons = ao_scheme_cons_fetch();
 144                 if (!new)
 145                         return AO_SCHEME_NIL;
 146                 new->car = cons->car;
 147                 new->cdr = AO_SCHEME_NIL;
 148                 if (!head)
 149                         head = new;
 150                 else
 151                         tail->cdr = ao_scheme_cons_poly(new);
 152                 tail = new;
 153                 cdr = cons->cdr;
 154                 if (!ao_scheme_is_cons(cdr)) {
 155                         tail->cdr = cdr;
 156                         break;
 157                 }
 158                 cons = ao_scheme_poly_cons(cdr);
 159         }
 160         return head;
 161 }
 162
 163 void
 164 ao_scheme_cons_free(struct ao_scheme_cons *cons)
 165 {
 166 #if DBG_FREE_CONS
 167         ao_scheme_cons_check(cons);
 168 #endif
 169         while (cons) {
 170                 ao_poly cdr = cons->cdr;
 171                 cons->cdr = ao_scheme_cons_poly(ao_scheme_cons_free_list);
 172                 ao_scheme_cons_free_list = cons;
 173                 cons = ao_scheme_poly_cons(cdr);
 174         }
 175 }
 176
 177 void
 178 ao_scheme_cons_write(FILE *out, ao_poly c, bool write)
 179 {
 180         struct ao_scheme_cons   *cons = ao_scheme_poly_cons(c);
 181         struct ao_scheme_cons   *clear = cons;
 182         ao_poly                 cdr;
 183         int                     written = 0;
 184
 185         ao_scheme_print_start();
 186         fprintf(out, "(");
 187         while (cons) {
 188                 if (written != 0)
 189                         fprintf(out, " ");
 190
 191                 /* Note if there's recursion in printing. Not
 192                  * as good as actual references, but at least
 193                  * we don't infinite loop...
 194                  */
 195                 if (ao_scheme_print_mark_addr(cons)) {
 196                         fprintf(out, "...");
 197                         break;
 198                 }
 199
 200                 ao_scheme_poly_write(out, cons->car, write);
 201
 202                 /* keep track of how many pairs have been printed */
 203                 written++;
 204
 205                 cdr = cons->cdr;
 206                 if (!ao_scheme_is_cons(cdr)) {
 207                         fprintf(out, " . ");
 208                         ao_scheme_poly_write(out, cdr, write);
 209                         break;
 210                 }
 211                 cons = ao_scheme_poly_cons(cdr);
 212         }
 213         fprintf(out, ")");
 214
 215         if (ao_scheme_print_stop()) {
 216
 217                 /* If we're still printing, clear the print marks on
 218                  * all printed pairs
 219                  */
 220                 while (written--) {
 221                         ao_scheme_print_clear_addr(clear);
 222                         clear = ao_scheme_poly_cons(clear->cdr);
 223                 }
 224         }
 225 }
 226
 227 int
 228 ao_scheme_cons_length(struct ao_scheme_cons *cons)
 229 {
 230         int     len = 0;
 231         while (cons) {
 232                 len++;
 233                 cons = ao_scheme_cons_cdr(cons);
 234         }
 235         return len;
 236 }
 237
 238 ao_poly
 239 ao_scheme_do_car(struct ao_scheme_cons *cons)
 240 {
 241         struct ao_scheme_cons *pair;
 242
 243         if (!ao_scheme_parse_args(_ao_scheme_atom_car, cons,
 244                                   AO_SCHEME_CONS, &pair,
 245                                   AO_SCHEME_ARG_END))
 246                 return AO_SCHEME_NIL;
 247         return pair->car;
 248 }
 249
 250 ao_poly
 251 ao_scheme_do_cdr(struct ao_scheme_cons *cons)
 252 {
 253         struct ao_scheme_cons *pair;
 254
 255         if (!ao_scheme_parse_args(_ao_scheme_atom_cdr, cons,
 256                                   AO_SCHEME_CONS, &pair,
 257                                   AO_SCHEME_ARG_END))
 258                 return AO_SCHEME_NIL;
 259         return pair->cdr;
 260 }
 261
 262 ao_poly
 263 ao_scheme_do_cons(struct ao_scheme_cons *cons)
 264 {
 265         ao_poly car, cdr;
 266
 267         if (!ao_scheme_parse_args(_ao_scheme_atom_cons, cons,
 268                                   AO_SCHEME_POLY, &car,
 269                                   AO_SCHEME_POLY, &cdr,
 270                                   AO_SCHEME_ARG_END))
 271                 return AO_SCHEME_NIL;
 272         return ao_scheme_cons(car, cdr);
 273 }
 274
 275 ao_poly
 276 ao_scheme_do_last(struct ao_scheme_cons *cons)
 277 {
 278         struct ao_scheme_cons   *pair;
 279
 280         if (!ao_scheme_parse_args(_ao_scheme_atom_last, cons,
 281                                   AO_SCHEME_CONS | AO_SCHEME_ARG_NIL_OK, &pair,
 282                                   AO_SCHEME_ARG_END))
 283                 return AO_SCHEME_NIL;
 284         while (pair) {
 285                 if (!pair->cdr)
 286                         return pair->car;
 287                 pair = ao_scheme_cons_cdr(pair);
 288         }
 289         return AO_SCHEME_NIL;
 290 }
 291
 292 ao_poly
 293 ao_scheme_do_length(struct ao_scheme_cons *cons)
 294 {
 295         struct ao_scheme_cons   *pair;
 296         if (!ao_scheme_parse_args(_ao_scheme_atom_length, cons,
 297                                   AO_SCHEME_CONS | AO_SCHEME_ARG_NIL_OK, &pair,
 298                                   AO_SCHEME_ARG_END))
 299                 return AO_SCHEME_NIL;
 300         return ao_scheme_integer_poly(ao_scheme_cons_length(pair));
 301 }
 302
 303 ao_poly
 304 ao_scheme_do_list_copy(struct ao_scheme_cons *cons)
 305 {
 306         struct ao_scheme_cons   *pair;
 307
 308         if (!ao_scheme_parse_args(_ao_scheme_atom_list2dcopy, cons,
 309                                   AO_SCHEME_CONS | AO_SCHEME_ARG_NIL_OK, &pair,
 310                                   AO_SCHEME_ARG_END))
 311                 return AO_SCHEME_NIL;
 312         return ao_scheme_cons_poly(ao_scheme_cons_copy(pair));
 313 }
 314
 315 ao_poly
 316 ao_scheme_do_list_tail(struct ao_scheme_cons *cons)
 317 {
 318         ao_poly                 list;
 319         int32_t                 v;
 320
 321         if (!ao_scheme_parse_args(_ao_scheme_atom_list2dtail, cons,
 322                                   AO_SCHEME_CONS | AO_SCHEME_ARG_NIL_OK | AO_SCHEME_ARG_RET_POLY, &list,
 323                                   AO_SCHEME_INT, &v,
 324                                   AO_SCHEME_ARG_END))
 325                 return AO_SCHEME_NIL;
 326
 327         while (v > 0) {
 328                 if (!list)
 329                         return ao_scheme_error(AO_SCHEME_INVALID, "%v: ran off end", _ao_scheme_atom_list2dtail);
 330                 if (!ao_scheme_is_cons(list))
 331                         return ao_scheme_error(AO_SCHEME_INVALID, "%v: invalid list", _ao_scheme_atom_list2dtail);
 332                 list = ao_scheme_poly_cons(list)->cdr;
 333                 v--;
 334         }
 335         return list;
 336 }
 337
 338 ao_poly
 339 ao_scheme_do_pairp(struct ao_scheme_cons *cons)
 340 {
 341         ao_poly val;
 342
 343         if (!ao_scheme_parse_args(_ao_scheme_atom_pair3f, cons,
 344                                   AO_SCHEME_POLY, &val,
 345                                   AO_SCHEME_ARG_END))
 346                 return AO_SCHEME_NIL;
 347         if (ao_scheme_is_pair(val))
 348                 return _ao_scheme_bool_true;
 349         return _ao_scheme_bool_false;
 350 }
 351
 352 /* This one is special -- a list is either nil or
 353  * a 'proper' list with only cons cells
 354  */
 355 ao_poly
 356 ao_scheme_do_listp(struct ao_scheme_cons *cons)
 357 {
 358         ao_poly val;
 359
 360         if (!ao_scheme_parse_args(_ao_scheme_atom_pair3f, cons,
 361                                   AO_SCHEME_POLY, &val,
 362                                   AO_SCHEME_ARG_END))
 363                 return AO_SCHEME_NIL;
 364         for (;;) {
 365                 if (val == AO_SCHEME_NIL)
 366                         return _ao_scheme_bool_true;
 367                 if (!ao_scheme_is_cons(val))
 368                         return _ao_scheme_bool_false;
 369                 val = ao_scheme_poly_cons(val)->cdr;
 370         }
 371 }
 372
 373 ao_poly
 374 ao_scheme_do_set_car(struct ao_scheme_cons *cons)
 375 {
 376         struct ao_scheme_cons   *pair;
 377         ao_poly                 val;
 378
 379         if (!ao_scheme_parse_args(_ao_scheme_atom_set2dcar21, cons,
 380                                   AO_SCHEME_CONS, &pair,
 381                                   AO_SCHEME_POLY, &val,
 382                                   AO_SCHEME_ARG_END))
 383                 return AO_SCHEME_NIL;
 384         pair->car = val;
 385         return val;
 386 }
 387
 388 ao_poly
 389 ao_scheme_do_set_cdr(struct ao_scheme_cons *cons)
 390 {
 391         struct ao_scheme_cons   *pair;
 392         ao_poly                 val;
 393
 394         if (!ao_scheme_parse_args(_ao_scheme_atom_set2dcar21, cons,
 395                                   AO_SCHEME_CONS, &pair,
 396                                   AO_SCHEME_POLY, &val,
 397                                   AO_SCHEME_ARG_END))
 398                 return AO_SCHEME_NIL;
 399         pair->cdr = val;
 400         return val;
 401 }
 402