mrbgems/mruby-struct/src/struct.c

   1 /*
   2 ** struct.c - Struct class
   3 **
   4 ** See Copyright Notice in mruby.h
   5 */
   6
   7 #include <ctype.h>
   8 #include <string.h>
   9 #include "mruby.h"
  10 #include "mruby/array.h"
  11 #include "mruby/string.h"
  12 #include "mruby/class.h"
  13 #include "mruby/variable.h"
  14 #include "mruby/hash.h"
  15 #include "mruby/range.h"
  16
  17 #define RSTRUCT_LEN(st) mrb_ary_ptr(st)->len
  18 #define RSTRUCT_PTR(st) mrb_ary_ptr(st)->ptr
  19
  20 static struct RClass *
  21 struct_class(mrb_state *mrb)
  22 {
  23   return mrb_class_get(mrb, "Struct");
  24 }
  25
  26 static inline mrb_value
  27 struct_ivar_get(mrb_state *mrb, mrb_value c, mrb_sym id)
  28 {
  29   struct RClass* kclass;
  30   struct RClass* sclass = struct_class(mrb);
  31   mrb_value ans;
  32
  33   for (;;) {
  34     ans = mrb_iv_get(mrb, c, id);
  35     if (!mrb_nil_p(ans)) return ans;
  36     kclass = RCLASS_SUPER(c);
  37     if (kclass == 0 || kclass == sclass)
  38       return mrb_nil_value();
  39     c = mrb_obj_value(kclass);
  40   }
  41 }
  42
  43 static mrb_value
  44 mrb_struct_s_members(mrb_state *mrb, mrb_value klass)
  45 {
  46   mrb_value members = struct_ivar_get(mrb, klass, mrb_intern_lit(mrb, "__members__"));
  47
  48   if (mrb_nil_p(members)) {
  49     mrb_raise(mrb, E_TYPE_ERROR, "uninitialized struct");
  50   }
  51   if (!mrb_array_p(members)) {
  52     mrb_raise(mrb, E_TYPE_ERROR, "corrupted struct");
  53   }
  54   return members;
  55 }
  56
  57 static mrb_value
  58 mrb_struct_members(mrb_state *mrb, mrb_value s)
  59 {
  60   mrb_value members = mrb_struct_s_members(mrb, mrb_obj_value(mrb_obj_class(mrb, s)));
  61   if (!strcmp(mrb_class_name(mrb, mrb_obj_class(mrb, s)), "Struct")) {
  62     if (RSTRUCT_LEN(s) != RARRAY_LEN(members)) {
  63       mrb_raisef(mrb, E_TYPE_ERROR,
  64                  "struct size differs (%S required %S given)",
  65                  mrb_fixnum_value(RARRAY_LEN(members)), mrb_fixnum_value(RSTRUCT_LEN(s)));
  66     }
  67   }
  68   return members;
  69 }
  70
  71 static mrb_value
  72 mrb_struct_s_members_m(mrb_state *mrb, mrb_value klass)
  73 {
  74   mrb_value members, ary;
  75
  76   members = mrb_struct_s_members(mrb, klass);
  77   ary = mrb_ary_new_capa(mrb, RARRAY_LEN(members));
  78   mrb_ary_replace(mrb, ary, members);
  79   return ary;
  80 }
  81
  82 /* 15.2.18.4.6  */
  83 /*
  84  *  call-seq:
  85  *     struct.members    -> array
  86  *
  87  *  Returns an array of strings representing the names of the instance
  88  *  variables.
  89  *
  90  *     Customer = Struct.new(:name, :address, :zip)
  91  *     joe = Customer.new("Joe Smith", "123 Maple, Anytown NC", 12345)
  92  *     joe.members   #=> [:name, :address, :zip]
  93  */
  94
  95 static mrb_value
  96 mrb_struct_members_m(mrb_state *mrb, mrb_value obj)
  97 {
  98   return mrb_struct_s_members_m(mrb, mrb_obj_value(mrb_obj_class(mrb, obj)));
  99 }
 100
 101 static mrb_value
 102 mrb_struct_getmember(mrb_state *mrb, mrb_value obj, mrb_sym id)
 103 {
 104   mrb_value members, slot, *ptr;
 105   const mrb_value *ptr_members;
 106   mrb_int i, len;
 107
 108   ptr = RSTRUCT_PTR(obj);
 109   members = mrb_struct_members(mrb, obj);
 110   ptr_members = RARRAY_PTR(members);
 111   slot = mrb_symbol_value(id);
 112   len = RARRAY_LEN(members);
 113   for (i=0; i<len; i++) {
 114     if (mrb_obj_equal(mrb, ptr_members[i], slot)) {
 115       return ptr[i];
 116     }
 117   }
 118   mrb_raisef(mrb, E_INDEX_ERROR, "`%S' is not a struct member", mrb_sym2str(mrb, id));
 119   return mrb_nil_value();       /* not reached */
 120 }
 121
 122 static mrb_value
 123 mrb_struct_ref(mrb_state *mrb, mrb_value obj)
 124 {
 125   return mrb_struct_getmember(mrb, obj, mrb->c->ci->mid);
 126 }
 127
 128 static mrb_value mrb_struct_ref0(mrb_state* mrb, mrb_value obj) {return RSTRUCT_PTR(obj)[0];}
 129 static mrb_value mrb_struct_ref1(mrb_state* mrb, mrb_value obj) {return RSTRUCT_PTR(obj)[1];}
 130 static mrb_value mrb_struct_ref2(mrb_state* mrb, mrb_value obj) {return RSTRUCT_PTR(obj)[2];}
 131 static mrb_value mrb_struct_ref3(mrb_state* mrb, mrb_value obj) {return RSTRUCT_PTR(obj)[3];}
 132 static mrb_value mrb_struct_ref4(mrb_state* mrb, mrb_value obj) {return RSTRUCT_PTR(obj)[4];}
 133 static mrb_value mrb_struct_ref5(mrb_state* mrb, mrb_value obj) {return RSTRUCT_PTR(obj)[5];}
 134 static mrb_value mrb_struct_ref6(mrb_state* mrb, mrb_value obj) {return RSTRUCT_PTR(obj)[6];}
 135 static mrb_value mrb_struct_ref7(mrb_state* mrb, mrb_value obj) {return RSTRUCT_PTR(obj)[7];}
 136 static mrb_value mrb_struct_ref8(mrb_state* mrb, mrb_value obj) {return RSTRUCT_PTR(obj)[8];}
 137 static mrb_value mrb_struct_ref9(mrb_state* mrb, mrb_value obj) {return RSTRUCT_PTR(obj)[9];}
 138
 139 #define numberof(array) (int)(sizeof(array) / sizeof((array)[0]))
 140 #define N_REF_FUNC numberof(ref_func)
 141
 142 static const mrb_func_t ref_func[] = {
 143   mrb_struct_ref0,
 144   mrb_struct_ref1,
 145   mrb_struct_ref2,
 146   mrb_struct_ref3,
 147   mrb_struct_ref4,
 148   mrb_struct_ref5,
 149   mrb_struct_ref6,
 150   mrb_struct_ref7,
 151   mrb_struct_ref8,
 152   mrb_struct_ref9,
 153 };
 154
 155 static mrb_sym
 156 mrb_id_attrset(mrb_state *mrb, mrb_sym id)
 157 {
 158   const char *name;
 159   char *buf;
 160   mrb_int len;
 161   mrb_sym mid;
 162
 163   name = mrb_sym2name_len(mrb, id, &len);
 164   buf = (char *)mrb_malloc(mrb, (size_t)len+2);
 165   memcpy(buf, name, (size_t)len);
 166   buf[len] = '=';
 167   buf[len+1] = '\0';
 168
 169   mid = mrb_intern(mrb, buf, len+1);
 170   mrb_free(mrb, buf);
 171   return mid;
 172 }
 173
 174 static mrb_value
 175 mrb_struct_set(mrb_state *mrb, mrb_value obj, mrb_value val)
 176 {
 177   const char *name;
 178   mrb_int i, len, slen;
 179   mrb_sym mid;
 180   mrb_value members, slot, *ptr;
 181   const mrb_value *ptr_members;
 182
 183   /* get base id */
 184   name = mrb_sym2name_len(mrb, mrb->c->ci->mid, &slen);
 185   mid = mrb_intern(mrb, name, slen-1); /* omit last "=" */
 186
 187   members = mrb_struct_members(mrb, obj);
 188   ptr_members = RARRAY_PTR(members);
 189   len = RARRAY_LEN(members);
 190   ptr = RSTRUCT_PTR(obj);
 191   for (i=0; i<len; i++) {
 192     slot = ptr_members[i];
 193     if (mrb_symbol(slot) == mid) {
 194       return ptr[i] = val;
 195     }
 196   }
 197   mrb_raisef(mrb, E_INDEX_ERROR, "`%S' is not a struct member", mrb_sym2str(mrb, mid));
 198   return mrb_nil_value();       /* not reached */
 199 }
 200
 201 static mrb_value
 202 mrb_struct_set_m(mrb_state *mrb, mrb_value obj)
 203 {
 204   mrb_value val;
 205
 206   mrb_get_args(mrb, "o", &val);
 207   return mrb_struct_set(mrb, obj, val);
 208 }
 209
 210 static mrb_bool
 211 is_local_id(mrb_state *mrb, const char *name)
 212 {
 213   if (!name) return FALSE;
 214   return !ISUPPER(name[0]);
 215 }
 216
 217 static mrb_bool
 218 is_const_id(mrb_state *mrb, const char *name)
 219 {
 220   if (!name) return FALSE;
 221   return ISUPPER(name[0]);
 222 }
 223
 224 static void
 225 make_struct_define_accessors(mrb_state *mrb, mrb_value members, struct RClass *c)
 226 {
 227   const mrb_value *ptr_members = RARRAY_PTR(members);
 228   mrb_int i;
 229   mrb_int len = RARRAY_LEN(members);
 230   int ai = mrb_gc_arena_save(mrb);
 231
 232   for (i=0; i<len; i++) {
 233     mrb_sym id = mrb_symbol(ptr_members[i]);
 234     const char *name = mrb_sym2name_len(mrb, id, NULL);
 235
 236     if (is_local_id(mrb, name) || is_const_id(mrb, name)) {
 237       if (i < N_REF_FUNC) {
 238         mrb_define_method_id(mrb, c, id, ref_func[i], MRB_ARGS_NONE());
 239       }
 240       else {
 241         mrb_define_method_id(mrb, c, id, mrb_struct_ref, MRB_ARGS_NONE());
 242       }
 243       mrb_define_method_id(mrb, c, mrb_id_attrset(mrb, id), mrb_struct_set_m, MRB_ARGS_REQ(1));
 244       mrb_gc_arena_restore(mrb, ai);
 245     }
 246   }
 247 }
 248
 249 static mrb_value
 250 make_struct(mrb_state *mrb, mrb_value name, mrb_value members, struct RClass * klass)
 251 {
 252   mrb_value nstr;
 253   mrb_sym id;
 254   struct RClass *c;
 255
 256   if (mrb_nil_p(name)) {
 257     c = mrb_class_new(mrb, klass);
 258   }
 259   else {
 260     /* old style: should we warn? */
 261     name = mrb_str_to_str(mrb, name);
 262     id = mrb_obj_to_sym(mrb, name);
 263     if (!is_const_id(mrb, mrb_sym2name_len(mrb, id, NULL))) {
 264       mrb_name_error(mrb, id, "identifier %S needs to be constant", name);
 265     }
 266     if (mrb_const_defined_at(mrb, klass, id)) {
 267       mrb_warn(mrb, "redefining constant Struct::%S", name);
 268       /* ?rb_mod_remove_const(klass, mrb_sym2name(mrb, id)); */
 269     }
 270     c = mrb_define_class_under(mrb, klass, RSTRING_PTR(name), klass);
 271   }
 272   MRB_SET_INSTANCE_TT(c, MRB_TT_ARRAY);
 273   nstr = mrb_obj_value(c);
 274   mrb_iv_set(mrb, nstr, mrb_intern_lit(mrb, "__members__"), members);
 275
 276   mrb_define_class_method(mrb, c, "new", mrb_instance_new, MRB_ARGS_ANY());
 277   mrb_define_class_method(mrb, c, "[]", mrb_instance_new, MRB_ARGS_ANY());
 278   mrb_define_class_method(mrb, c, "members", mrb_struct_s_members_m, MRB_ARGS_NONE());
 279   /* RSTRUCT(nstr)->basic.c->super = c->c; */
 280   make_struct_define_accessors(mrb, members, c);
 281   return nstr;
 282 }
 283
 284 /* 15.2.18.3.1  */
 285 /*
 286  *  call-seq:
 287  *     Struct.new( [aString] [, aSym]+> )    -> StructClass
 288  *     StructClass.new(arg, ...)             -> obj
 289  *     StructClass[arg, ...]                 -> obj
 290  *
 291  *  Creates a new class, named by <i>aString</i>, containing accessor
 292  *  methods for the given symbols. If the name <i>aString</i> is
 293  *  omitted, an anonymous structure class will be created. Otherwise,
 294  *  the name of this struct will appear as a constant in class
 295  *  <code>Struct</code>, so it must be unique for all
 296  *  <code>Struct</code>s in the system and should start with a capital
 297  *  letter. Assigning a structure class to a constant effectively gives
 298  *  the class the name of the constant.
 299  *
 300  *  <code>Struct::new</code> returns a new <code>Class</code> object,
 301  *  which can then be used to create specific instances of the new
 302  *  structure. The number of actual parameters must be
 303  *  less than or equal to the number of attributes defined for this
 304  *  class; unset parameters default to <code>nil</code>.  Passing too many
 305  *  parameters will raise an <code>ArgumentError</code>.
 306  *
 307  *  The remaining methods listed in this section (class and instance)
 308  *  are defined for this generated class.
 309  *
 310  *     # Create a structure with a name in Struct
 311  *     Struct.new("Customer", :name, :address)    #=> Struct::Customer
 312  *     Struct::Customer.new("Dave", "123 Main")   #=> #<struct Struct::Customer name="Dave", address="123 Main">
 313  *
 314  *     # Create a structure named by its constant
 315  *     Customer = Struct.new(:name, :address)     #=> Customer
 316  *     Customer.new("Dave", "123 Main")           #=> #<struct Customer name="Dave", address="123 Main">
 317  */
 318 static mrb_value
 319 mrb_struct_s_def(mrb_state *mrb, mrb_value klass)
 320 {
 321   mrb_value name, rest;
 322   mrb_value *pargv;
 323   mrb_int argcnt;
 324   mrb_int i;
 325   mrb_value b, st;
 326   mrb_sym id;
 327   mrb_value *argv;
 328   mrb_int argc;
 329
 330   name = mrb_nil_value();
 331   rest = mrb_nil_value();
 332   mrb_get_args(mrb, "*&", &argv, &argc, &b);
 333   if (argc == 0) { /* special case to avoid crash */
 334     rest = mrb_ary_new(mrb);
 335   }
 336   else {
 337     if (argc > 0) name = argv[0];
 338     if (argc > 1) rest = argv[1];
 339     if (mrb_array_p(rest)) {
 340       if (!mrb_nil_p(name) && mrb_symbol_p(name)) {
 341         /* 1stArgument:symbol -> name=nil rest=argv[0]-[n] */
 342         mrb_ary_unshift(mrb, rest, name);
 343         name = mrb_nil_value();
 344       }
 345     }
 346     else {
 347       pargv = &argv[1];
 348       argcnt = argc-1;
 349       if (!mrb_nil_p(name) && mrb_symbol_p(name)) {
 350         /* 1stArgument:symbol -> name=nil rest=argv[0]-[n] */
 351         name = mrb_nil_value();
 352         pargv = &argv[0];
 353         argcnt++;
 354       }
 355       rest = mrb_ary_new_from_values(mrb, argcnt, pargv);
 356     }
 357     for (i=0; i<RARRAY_LEN(rest); i++) {
 358       id = mrb_obj_to_sym(mrb, RARRAY_PTR(rest)[i]);
 359       mrb_ary_set(mrb, rest, i, mrb_symbol_value(id));
 360     }
 361   }
 362   st = make_struct(mrb, name, rest, struct_class(mrb));
 363   if (!mrb_nil_p(b)) {
 364     mrb_yield_with_class(mrb, b, 1, &st, st, mrb_class_ptr(klass));
 365   }
 366
 367   return st;
 368 }
 369
 370 static mrb_int
 371 num_members(mrb_state *mrb, struct RClass *klass)
 372 {
 373   mrb_value members;
 374
 375   members = struct_ivar_get(mrb, mrb_obj_value(klass), mrb_intern_lit(mrb, "__members__"));
 376   if (!mrb_array_p(members)) {
 377     mrb_raise(mrb, E_TYPE_ERROR, "broken members");
 378   }
 379   return RARRAY_LEN(members);
 380 }
 381
 382 /* 15.2.18.4.8  */
 383 /*
 384  */
 385 static mrb_value
 386 mrb_struct_initialize_withArg(mrb_state *mrb, mrb_int argc, mrb_value *argv, mrb_value self)
 387 {
 388   struct RClass *klass = mrb_obj_class(mrb, self);
 389   mrb_int i, n;
 390
 391   n = num_members(mrb, klass);
 392   if (n < argc) {
 393     mrb_raise(mrb, E_ARGUMENT_ERROR, "struct size differs");
 394   }
 395
 396   for (i = 0; i < argc; i++) {
 397     mrb_ary_set(mrb, self, i, argv[i]);
 398   }
 399   for (i = argc; i < n; i++) {
 400     mrb_ary_set(mrb, self, i, mrb_nil_value());
 401   }
 402   return self;
 403 }
 404
 405 static mrb_value
 406 mrb_struct_initialize_m(mrb_state *mrb, /*int argc, mrb_value *argv,*/ mrb_value self)
 407 {
 408   mrb_value *argv;
 409   mrb_int argc;
 410
 411   mrb_get_args(mrb, "*", &argv, &argc);
 412   return mrb_struct_initialize_withArg(mrb, argc, argv, self);
 413 }
 414
 415 static mrb_value
 416 inspect_struct(mrb_state *mrb, mrb_value s, mrb_bool recur)
 417 {
 418   const char *cn = mrb_class_name(mrb, mrb_obj_class(mrb, s));
 419   mrb_value members, str = mrb_str_new_lit(mrb, "#<struct ");
 420   mrb_value *ptr;
 421   const mrb_value *ptr_members;
 422   mrb_int i, len;
 423
 424   if (cn) {
 425     mrb_str_append(mrb, str, mrb_str_new_cstr(mrb, cn));
 426   }
 427   if (recur) {
 428     return mrb_str_cat_lit(mrb, str, ":...>");
 429   }
 430
 431   members = mrb_struct_members(mrb, s);
 432   ptr_members = RARRAY_PTR(members);
 433   ptr = RSTRUCT_PTR(s);
 434   len = RSTRUCT_LEN(s);
 435   for (i=0; i<len; i++) {
 436     mrb_value slot;
 437     mrb_sym id;
 438     const char *name;
 439     mrb_int namelen;
 440
 441     if (i > 0) {
 442       mrb_str_cat_lit(mrb, str, ", ");
 443     }
 444     else if (cn) {
 445       mrb_str_cat_lit(mrb, str, " ");
 446     }
 447     slot = ptr_members[i];
 448     id = mrb_symbol(slot);
 449     name = mrb_sym2name_len(mrb, id, &namelen);
 450     if (is_local_id(mrb, name) || is_const_id(mrb, name)) {
 451       mrb_str_append(mrb, str, mrb_str_new(mrb, name, namelen));
 452     }
 453     else {
 454       mrb_str_append(mrb, str, mrb_inspect(mrb, slot));
 455     }
 456     mrb_str_cat_lit(mrb, str, "=");
 457     mrb_str_append(mrb, str, mrb_inspect(mrb, ptr[i]));
 458   }
 459   mrb_str_cat_lit(mrb, str, ">");
 460
 461   return str;
 462 }
 463
 464 /*
 465  * call-seq:
 466  *   struct.to_s      -> string
 467  *   struct.inspect   -> string
 468  *
 469  * Describe the contents of this struct in a string.
 470  */
 471 static mrb_value
 472 mrb_struct_inspect(mrb_state *mrb, mrb_value s)
 473 {
 474   return inspect_struct(mrb, s, FALSE);
 475 }
 476
 477 /* 15.2.18.4.9  */
 478 /* :nodoc: */
 479 static mrb_value
 480 mrb_struct_init_copy(mrb_state *mrb, mrb_value copy)
 481 {
 482   mrb_value s;
 483   mrb_int i, len;
 484
 485   mrb_get_args(mrb, "o", &s);
 486
 487   if (mrb_obj_equal(mrb, copy, s)) return copy;
 488   if (!mrb_obj_is_instance_of(mrb, s, mrb_obj_class(mrb, copy))) {
 489     mrb_raise(mrb, E_TYPE_ERROR, "wrong argument class");
 490   }
 491   if (!mrb_array_p(s)) {
 492     mrb_raise(mrb, E_TYPE_ERROR, "corrupted struct");
 493   }
 494   if (RSTRUCT_LEN(copy) != RSTRUCT_LEN(s)) {
 495     mrb_raise(mrb, E_TYPE_ERROR, "struct size mismatch");
 496   }
 497   len = RSTRUCT_LEN(copy);
 498   for (i = 0; i < len; i++) {
 499     mrb_ary_set(mrb, copy, i, RSTRUCT_PTR(s)[i]);
 500   }
 501   return copy;
 502 }
 503
 504 static mrb_value
 505 struct_aref_sym(mrb_state *mrb, mrb_value s, mrb_sym id)
 506 {
 507   mrb_value *ptr, members;
 508   const mrb_value *ptr_members;
 509   mrb_int i, len;
 510
 511   ptr = RSTRUCT_PTR(s);
 512   members = mrb_struct_members(mrb, s);
 513   ptr_members = RARRAY_PTR(members);
 514   len = RARRAY_LEN(members);
 515   for (i=0; i<len; i++) {
 516     if (mrb_symbol(ptr_members[i]) == id) {
 517       return ptr[i];
 518     }
 519   }
 520   mrb_raisef(mrb, E_INDEX_ERROR, "no member '%S' in struct", mrb_sym2str(mrb, id));
 521   return mrb_nil_value();       /* not reached */
 522 }
 523
 524 static mrb_value
 525 struct_aref_int(mrb_state *mrb, mrb_value s, mrb_int i)
 526 {
 527   if (i < 0) i = RSTRUCT_LEN(s) + i;
 528   if (i < 0)
 529       mrb_raisef(mrb, E_INDEX_ERROR,
 530                  "offset %S too small for struct(size:%S)",
 531                  mrb_fixnum_value(i), mrb_fixnum_value(RSTRUCT_LEN(s)));
 532   if (RSTRUCT_LEN(s) <= i)
 533     mrb_raisef(mrb, E_INDEX_ERROR,
 534                "offset %S too large for struct(size:%S)",
 535                mrb_fixnum_value(i), mrb_fixnum_value(RSTRUCT_LEN(s)));
 536   return RSTRUCT_PTR(s)[i];
 537 }
 538
 539 /* 15.2.18.4.2  */
 540 /*
 541  *  call-seq:
 542  *     struct[symbol]    -> anObject
 543  *     struct[fixnum]    -> anObject
 544  *
 545  *  Attribute Reference---Returns the value of the instance variable
 546  *  named by <i>symbol</i>, or indexed (0..length-1) by
 547  *  <i>fixnum</i>. Will raise <code>NameError</code> if the named
 548  *  variable does not exist, or <code>IndexError</code> if the index is
 549  *  out of range.
 550  *
 551  *     Customer = Struct.new(:name, :address, :zip)
 552  *     joe = Customer.new("Joe Smith", "123 Maple, Anytown NC", 12345)
 553  *
 554  *     joe["name"]   #=> "Joe Smith"
 555  *     joe[:name]    #=> "Joe Smith"
 556  *     joe[0]        #=> "Joe Smith"
 557  */
 558 static mrb_value
 559 mrb_struct_aref(mrb_state *mrb, mrb_value s)
 560 {
 561   mrb_value idx;
 562
 563   mrb_get_args(mrb, "o", &idx);
 564   if (mrb_string_p(idx)) {
 565     mrb_value sym = mrb_check_intern_str(mrb, idx);
 566
 567     if (mrb_nil_p(sym)) {
 568       mrb_raisef(mrb, E_INDEX_ERROR, "no member '%S' in struct", idx);
 569     }
 570     idx = sym;
 571   }
 572   if (mrb_symbol_p(idx)) {
 573     return struct_aref_sym(mrb, s, mrb_symbol(idx));
 574   }
 575   return struct_aref_int(mrb, s, mrb_int(mrb, idx));
 576 }
 577
 578 static mrb_value
 579 mrb_struct_aset_sym(mrb_state *mrb, mrb_value s, mrb_sym id, mrb_value val)
 580 {
 581   mrb_value members, *ptr;
 582   const mrb_value *ptr_members;
 583   mrb_int i, len;
 584
 585   members = mrb_struct_members(mrb, s);
 586   len = RARRAY_LEN(members);
 587   if (RSTRUCT_LEN(s) != len) {
 588     mrb_raisef(mrb, E_TYPE_ERROR,
 589                "struct size differs (%S required %S given)",
 590                mrb_fixnum_value(len), mrb_fixnum_value(RSTRUCT_LEN(s)));
 591   }
 592   ptr = RSTRUCT_PTR(s);
 593   ptr_members = RARRAY_PTR(members);
 594   for (i=0; i<len; i++) {
 595     if (mrb_symbol(ptr_members[i]) == id) {
 596       ptr[i] = val;
 597       return val;
 598     }
 599   }
 600   mrb_raisef(mrb, E_INDEX_ERROR, "no member '%S' in struct", mrb_sym2str(mrb, id));
 601   return val;                   /* not reach */
 602 }
 603
 604 /* 15.2.18.4.3  */
 605 /*
 606  *  call-seq:
 607  *     struct[symbol] = obj    -> obj
 608  *     struct[fixnum] = obj    -> obj
 609  *
 610  *  Attribute Assignment---Assigns to the instance variable named by
 611  *  <i>symbol</i> or <i>fixnum</i> the value <i>obj</i> and
 612  *  returns it. Will raise a <code>NameError</code> if the named
 613  *  variable does not exist, or an <code>IndexError</code> if the index
 614  *  is out of range.
 615  *
 616  *     Customer = Struct.new(:name, :address, :zip)
 617  *     joe = Customer.new("Joe Smith", "123 Maple, Anytown NC", 12345)
 618  *
 619  *     joe["name"] = "Luke"
 620  *     joe[:zip]   = "90210"
 621  *
 622  *     joe.name   #=> "Luke"
 623  *     joe.zip    #=> "90210"
 624  */
 625
 626 static mrb_value
 627 mrb_struct_aset(mrb_state *mrb, mrb_value s)
 628 {
 629   mrb_int i;
 630   mrb_value idx;
 631   mrb_value val;
 632
 633   mrb_get_args(mrb, "oo", &idx, &val);
 634
 635   if (mrb_string_p(idx)) {
 636     mrb_value sym = mrb_check_intern_str(mrb, idx);
 637
 638     if (mrb_nil_p(sym)) {
 639       mrb_raisef(mrb, E_INDEX_ERROR, "no member '%S' in struct", idx);
 640     }
 641     idx = sym;
 642   }
 643   if (mrb_symbol_p(idx)) {
 644     return mrb_struct_aset_sym(mrb, s, mrb_symbol(idx), val);
 645   }
 646
 647   i = mrb_int(mrb, idx);
 648   if (i < 0) i = RSTRUCT_LEN(s) + i;
 649   if (i < 0) {
 650     mrb_raisef(mrb, E_INDEX_ERROR,
 651                "offset %S too small for struct(size:%S)",
 652                mrb_fixnum_value(i), mrb_fixnum_value(RSTRUCT_LEN(s)));
 653   }
 654   if (RSTRUCT_LEN(s) <= i) {
 655     mrb_raisef(mrb, E_INDEX_ERROR,
 656                "offset %S too large for struct(size:%S)",
 657                mrb_fixnum_value(i), mrb_fixnum_value(RSTRUCT_LEN(s)));
 658   }
 659   return RSTRUCT_PTR(s)[i] = val;
 660 }
 661
 662 /* 15.2.18.4.1  */
 663 /*
 664  *  call-seq:
 665  *     struct == other_struct     -> true or false
 666  *
 667  *  Equality---Returns <code>true</code> if <i>other_struct</i> is
 668  *  equal to this one: they must be of the same class as generated by
 669  *  <code>Struct::new</code>, and the values of all instance variables
 670  *  must be equal (according to <code>Object#==</code>).
 671  *
 672  *     Customer = Struct.new(:name, :address, :zip)
 673  *     joe   = Customer.new("Joe Smith", "123 Maple, Anytown NC", 12345)
 674  *     joejr = Customer.new("Joe Smith", "123 Maple, Anytown NC", 12345)
 675  *     jane  = Customer.new("Jane Doe", "456 Elm, Anytown NC", 12345)
 676  *     joe == joejr   #=> true
 677  *     joe == jane    #=> false
 678  */
 679
 680 static mrb_value
 681 mrb_struct_equal(mrb_state *mrb, mrb_value s)
 682 {
 683   mrb_value s2;
 684   mrb_value *ptr, *ptr2;
 685   mrb_int i, len;
 686   mrb_bool equal_p;
 687
 688   mrb_get_args(mrb, "o", &s2);
 689   if (mrb_obj_equal(mrb, s, s2)) {
 690     equal_p = 1;
 691   }
 692   else if (!strcmp(mrb_class_name(mrb, mrb_obj_class(mrb, s)), "Struct") ||
 693            mrb_obj_class(mrb, s) != mrb_obj_class(mrb, s2)) {
 694     equal_p = 0;
 695   }
 696   else if (RSTRUCT_LEN(s) != RSTRUCT_LEN(s2)) {
 697     mrb_bug(mrb, "inconsistent struct"); /* should never happen */
 698     equal_p = 0; /* This substuture is just to suppress warnings. never called. */
 699   }
 700   else {
 701     ptr = RSTRUCT_PTR(s);
 702     ptr2 = RSTRUCT_PTR(s2);
 703     len = RSTRUCT_LEN(s);
 704     equal_p = 1;
 705     for (i=0; i<len; i++) {
 706       if (!mrb_equal(mrb, ptr[i], ptr2[i])) {
 707         equal_p = 0;
 708         break;
 709       }
 710     }
 711   }
 712
 713   return mrb_bool_value(equal_p);
 714 }
 715
 716 /* 15.2.18.4.12(x)  */
 717 /*
 718  * code-seq:
 719  *   struct.eql?(other)   -> true or false
 720  *
 721  * Two structures are equal if they are the same object, or if all their
 722  * fields are equal (using <code>eql?</code>).
 723  */
 724 static mrb_value
 725 mrb_struct_eql(mrb_state *mrb, mrb_value s)
 726 {
 727   mrb_value s2;
 728   mrb_value *ptr, *ptr2;
 729   mrb_int i, len;
 730   mrb_bool eql_p;
 731
 732   mrb_get_args(mrb, "o", &s2);
 733   if (mrb_obj_equal(mrb, s, s2)) {
 734     eql_p = 1;
 735   }
 736   else if (strcmp(mrb_class_name(mrb, mrb_obj_class(mrb, s2)), "Struct") ||
 737            mrb_obj_class(mrb, s) != mrb_obj_class(mrb, s2)) {
 738     eql_p = 0;
 739   }
 740   else if (RSTRUCT_LEN(s) != RSTRUCT_LEN(s2)) {
 741     mrb_bug(mrb, "inconsistent struct"); /* should never happen */
 742     eql_p = 0; /* This substuture is just to suppress warnings. never called. */
 743   }
 744   else {
 745     ptr = RSTRUCT_PTR(s);
 746     ptr2 = RSTRUCT_PTR(s2);
 747     len = RSTRUCT_LEN(s);
 748     eql_p = 1;
 749     for (i=0; i<len; i++) {
 750       if (!mrb_eql(mrb, ptr[i], ptr2[i])) {
 751         eql_p = 0;
 752         break;
 753       }
 754     }
 755   }
 756
 757   return mrb_bool_value(eql_p);
 758 }
 759
 760 /*
 761  * call-seq:
 762  *    struct.length   -> Fixnum
 763  *    struct.size     -> Fixnum
 764  *
 765  * Returns number of struct members.
 766  */
 767 static mrb_value
 768 mrb_struct_len(mrb_state *mrb, mrb_value self)
 769 {
 770   return mrb_fixnum_value(RSTRUCT_LEN(self));
 771 }
 772
 773 /*
 774  * call-seq:
 775  *    struct.to_a    -> array
 776  *    struct.values  -> array
 777  *
 778  * Create an array from struct values.
 779  */
 780 static mrb_value
 781 mrb_struct_to_a(mrb_state *mrb, mrb_value self)
 782 {
 783   return mrb_ary_new_from_values(mrb, RSTRUCT_LEN(self), RSTRUCT_PTR(self));
 784 }
 785
 786 /*
 787  * call-seq:
 788  *    struct.to_h -> hash
 789  *
 790  * Create a hash from member names and struct values.
 791  */
 792 static mrb_value
 793 mrb_struct_to_h(mrb_state *mrb, mrb_value self)
 794 {
 795   mrb_value members, ret;
 796   mrb_int i;
 797
 798   members = mrb_struct_s_members(mrb, mrb_obj_value(mrb_class(mrb, self)));
 799   ret = mrb_hash_new_capa(mrb, RARRAY_LEN(members));
 800
 801   for (i = 0; i < RARRAY_LEN(members); ++i) {
 802     mrb_hash_set(mrb, ret, RARRAY_PTR(members)[i], RSTRUCT_PTR(self)[i]);
 803   }
 804
 805   return ret;
 806 }
 807
 808 static mrb_value
 809 mrb_struct_values_at(mrb_state *mrb, mrb_value self)
 810 {
 811   mrb_int argc;
 812   mrb_value *argv;
 813
 814   mrb_get_args(mrb, "*", &argv, &argc);
 815
 816   return mrb_get_values_at(mrb, self, RSTRUCT_LEN(self), argc, argv, struct_aref_int);
 817 }
 818
 819 /*
 820  *  A <code>Struct</code> is a convenient way to bundle a number of
 821  *  attributes together, using accessor methods, without having to write
 822  *  an explicit class.
 823  *
 824  *  The <code>Struct</code> class is a generator of specific classes,
 825  *  each one of which is defined to hold a set of variables and their
 826  *  accessors. In these examples, we'll call the generated class
 827  *  ``<i>Customer</i>Class,'' and we'll show an example instance of that
 828  *  class as ``<i>Customer</i>Inst.''
 829  *
 830  *  In the descriptions that follow, the parameter <i>symbol</i> refers
 831  *  to a symbol, which is either a quoted string or a
 832  *  <code>Symbol</code> (such as <code>:name</code>).
 833  */
 834 void
 835 mrb_mruby_struct_gem_init(mrb_state* mrb)
 836 {
 837   struct RClass *st;
 838   st = mrb_define_class(mrb, "Struct",  mrb->object_class);
 839
 840   mrb_define_class_method(mrb, st, "new",             mrb_struct_s_def,       MRB_ARGS_ANY());  /* 15.2.18.3.1  */
 841
 842   mrb_define_method(mrb, st,       "==",              mrb_struct_equal,       MRB_ARGS_REQ(1)); /* 15.2.18.4.1  */
 843   mrb_define_method(mrb, st,       "[]",              mrb_struct_aref,        MRB_ARGS_REQ(1)); /* 15.2.18.4.2  */
 844   mrb_define_method(mrb, st,       "[]=",             mrb_struct_aset,        MRB_ARGS_REQ(2)); /* 15.2.18.4.3  */
 845   mrb_define_method(mrb, st,       "members",         mrb_struct_members_m,   MRB_ARGS_NONE()); /* 15.2.18.4.6  */
 846   mrb_define_method(mrb, st,       "initialize",      mrb_struct_initialize_m,MRB_ARGS_ANY());  /* 15.2.18.4.8  */
 847   mrb_define_method(mrb, st,       "initialize_copy", mrb_struct_init_copy,   MRB_ARGS_REQ(1)); /* 15.2.18.4.9  */
 848   mrb_define_method(mrb, st,       "inspect",         mrb_struct_inspect,     MRB_ARGS_NONE()); /* 15.2.18.4.10(x)  */
 849   mrb_define_alias(mrb, st,        "to_s", "inspect");                                      /* 15.2.18.4.11(x)  */
 850   mrb_define_method(mrb, st,       "eql?",            mrb_struct_eql,         MRB_ARGS_REQ(1)); /* 15.2.18.4.12(x)  */
 851
 852   mrb_define_method(mrb, st,        "size",           mrb_struct_len,         MRB_ARGS_NONE());
 853   mrb_define_method(mrb, st,        "length",         mrb_struct_len,         MRB_ARGS_NONE());
 854   mrb_define_method(mrb, st,        "to_a",           mrb_struct_to_a,        MRB_ARGS_NONE());
 855   mrb_define_method(mrb, st,        "values",         mrb_struct_to_a,        MRB_ARGS_NONE());
 856   mrb_define_method(mrb, st,        "to_h",           mrb_struct_to_h,        MRB_ARGS_NONE());
 857   mrb_define_method(mrb, st,        "values_at",      mrb_struct_values_at,   MRB_ARGS_NONE());
 858 }
 859
 860 void
 861 mrb_mruby_struct_gem_final(mrb_state* mrb)
 862 {
 863 }