src/hash.c

   1 /*
   2 ** hash.c - Hash class
   3 **
   4 ** See Copyright Notice in mruby.h
   5 */
   6
   7 #include "mruby.h"
   8 #include "mruby/hash.h"
   9 #include "mruby/khash.h"
  10 #include "mruby/class.h"
  11 #include "mruby/array.h"
  12 #include "mruby/string.h"
  13 #include "mruby/variable.h"
  14
  15 static inline khint_t
  16 mrb_hash_ht_hash_func(mrb_state *mrb, mrb_value key)
  17 {
  18   khint_t h = (khint_t)mrb_type(key) << 24;
  19   mrb_value h2;
  20
  21   h2 = mrb_funcall(mrb, key, "hash", 0, 0);
  22   h ^= h2.value.i;
  23   return h;
  24 }
  25
  26 static inline khint_t
  27 mrb_hash_ht_hash_equal(mrb_state *mrb, mrb_value a, mrb_value b)
  28 {
  29   return mrb_eql(mrb, a, b);
  30 }
  31
  32 KHASH_DECLARE(ht, mrb_value, mrb_value, 1)
  33 KHASH_DEFINE (ht, mrb_value, mrb_value, 1, mrb_hash_ht_hash_func, mrb_hash_ht_hash_equal)
  34
  35 static void mrb_hash_modify(mrb_state *mrb, mrb_value hash);
  36
  37 static inline mrb_value
  38 mrb_hash_ht_key(mrb_state *mrb, mrb_value key)
  39 {
  40   if (mrb_string_p(key))
  41     return mrb_str_dup(mrb, key);
  42   else
  43     return key;
  44 }
  45
  46 #define KEY(key) mrb_hash_ht_key(mrb, key)
  47
  48 void
  49 mrb_gc_mark_ht(mrb_state *mrb, struct RHash *hash)
  50 {
  51   khiter_t k;
  52   khash_t(ht) *h = hash->ht;
  53
  54   if (!h) return;
  55   for (k = kh_begin(h); k != kh_end(h); k++) {
  56     if (kh_exist(h, k)) {
  57       mrb_value key = kh_key(h, k);
  58       mrb_value val = kh_value(h, k);
  59
  60       mrb_gc_mark_value(mrb, key);
  61       mrb_gc_mark_value(mrb, val);
  62     }
  63   }
  64 }
  65
  66 size_t
  67 mrb_gc_mark_ht_size(mrb_state *mrb, struct RHash *hash)
  68 {
  69   if (!hash->ht) return 0;
  70   return kh_size(hash->ht)*2;
  71 }
  72
  73 void
  74 mrb_gc_free_ht(mrb_state *mrb, struct RHash *hash)
  75 {
  76   if (hash->ht) kh_destroy(ht, hash->ht);
  77 }
  78
  79
  80 mrb_value
  81 mrb_hash_new_capa(mrb_state *mrb, int capa)
  82 {
  83   struct RHash *h;
  84
  85   h = (struct RHash*)mrb_obj_alloc(mrb, MRB_TT_HASH, mrb->hash_class);
  86   h->ht = kh_init(ht, mrb);
  87   if (capa > 0) {
  88     kh_resize(ht, h->ht, capa);
  89   }
  90   h->iv = 0;
  91   return mrb_obj_value(h);
  92 }
  93
  94 mrb_value
  95 mrb_hash_new(mrb_state *mrb)
  96 {
  97   return mrb_hash_new_capa(mrb, 0);
  98 }
  99
 100 mrb_value
 101 mrb_hash_get(mrb_state *mrb, mrb_value hash, mrb_value key)
 102 {
 103   khash_t(ht) *h = RHASH_TBL(hash);
 104   khiter_t k;
 105
 106   if (h) {
 107     k = kh_get(ht, h, key);
 108     if (k != kh_end(h))
 109       return kh_value(h, k);
 110   }
 111
 112   /* not found */
 113   if (MRB_RHASH_PROCDEFAULT_P(hash)) {
 114     return mrb_funcall(mrb, RHASH_PROCDEFAULT(hash), "call", 2, hash, key);
 115   }
 116   return RHASH_IFNONE(hash);
 117 }
 118
 119 mrb_value
 120 mrb_hash_fetch(mrb_state *mrb, mrb_value hash, mrb_value key, mrb_value def)
 121 {
 122   khash_t(ht) *h = RHASH_TBL(hash);
 123   khiter_t k;
 124
 125   if (h) {
 126     k = kh_get(ht, h, key);
 127     if (k != kh_end(h))
 128       return kh_value(h, k);
 129   }
 130
 131   /* not found */
 132   return def;
 133 }
 134
 135 void
 136 mrb_hash_set(mrb_state *mrb, mrb_value hash, mrb_value key, mrb_value val) /* mrb_hash_aset */
 137 {
 138   khash_t(ht) *h;
 139   khiter_t k;
 140
 141   mrb_hash_modify(mrb, hash);
 142   h = RHASH_TBL(hash);
 143
 144   if (!h) h = RHASH_TBL(hash) = kh_init(ht, mrb);
 145   k = kh_get(ht, h, key);
 146   if (k == kh_end(h)) {
 147     /* expand */
 148     k = kh_put(ht, h, KEY(key));
 149   }
 150
 151   kh_value(h, k) = val;
 152   mrb_write_barrier(mrb, (struct RBasic*)RHASH(hash));
 153   return;
 154 }
 155
 156 mrb_value
 157 mrb_hash_dup(mrb_state *mrb, mrb_value hash)
 158 {
 159   struct RHash* ret;
 160   khash_t(ht) *h, *ret_h;
 161   khiter_t k, ret_k;
 162
 163   h = RHASH_TBL(hash);
 164   ret = (struct RHash*)mrb_obj_alloc(mrb, MRB_TT_HASH, mrb->hash_class);
 165   ret->ht = kh_init(ht, mrb);
 166
 167   if (kh_size(h) > 0) {
 168     ret_h = ret->ht;
 169
 170     for (k = kh_begin(h); k != kh_end(h); k++) {
 171       if (kh_exist(h,k)) {
 172         ret_k = kh_put(ht, ret_h, KEY(kh_key(h,k)));
 173         kh_val(ret_h, ret_k) = kh_val(h,k);
 174       }
 175     }
 176   }
 177
 178   return mrb_obj_value(ret);
 179 }
 180
 181 mrb_value
 182 mrb_check_hash_type(mrb_state *mrb, mrb_value hash)
 183 {
 184   return mrb_check_convert_type(mrb, hash, MRB_TT_HASH, "Hash", "to_hash");
 185 }
 186
 187 khash_t(ht) *
 188 mrb_hash_tbl(mrb_state *mrb, mrb_value hash)
 189 {
 190   khash_t(ht) *h = RHASH_TBL(hash);
 191
 192   if (!h) {
 193     RHASH_TBL(hash) = kh_init(ht, mrb);
 194   }
 195   return h;
 196 }
 197
 198 static void
 199 mrb_hash_modify(mrb_state *mrb, mrb_value hash)
 200 {
 201   mrb_hash_tbl(mrb, hash);
 202 }
 203
 204 /* 15.2.13.4.16 */
 205 /*
 206  *  call-seq:
 207  *     Hash.new                          -> new_hash
 208  *     Hash.new(obj)                     -> new_hash
 209  *     Hash.new {|hash, key| block }     -> new_hash
 210  *
 211  *  Returns a new, empty hash. If this hash is subsequently accessed by
 212  *  a key that doesn't correspond to a hash entry, the value returned
 213  *  depends on the style of <code>new</code> used to create the hash. In
 214  *  the first form, the access returns <code>nil</code>. If
 215  *  <i>obj</i> is specified, this single object will be used for
 216  *  all <em>default values</em>. If a block is specified, it will be
 217  *  called with the hash object and the key, and should return the
 218  *  default value. It is the block's responsibility to store the value
 219  *  in the hash if required.
 220  *
 221  *     h = Hash.new("Go Fish")
 222  *     h["a"] = 100
 223  *     h["b"] = 200
 224  *     h["a"]           #=> 100
 225  *     h["c"]           #=> "Go Fish"
 226  *     # The following alters the single default object
 227  *     h["c"].upcase!   #=> "GO FISH"
 228  *     h["d"]           #=> "GO FISH"
 229  *     h.keys           #=> ["a", "b"]
 230  *
 231  *     # While this creates a new default object each time
 232  *     h = Hash.new { |hash, key| hash[key] = "Go Fish: #{key}" }
 233  *     h["c"]           #=> "Go Fish: c"
 234  *     h["c"].upcase!   #=> "GO FISH: C"
 235  *     h["d"]           #=> "Go Fish: d"
 236  *     h.keys           #=> ["c", "d"]
 237  *
 238  */
 239
 240 static mrb_value
 241 mrb_hash_init_core(mrb_state *mrb, mrb_value hash)
 242 {
 243   mrb_value block, ifnone;
 244   mrb_value *argv;
 245   int argc;
 246
 247   mrb_get_args(mrb, "o*", &block, &argv, &argc);
 248   mrb_hash_modify(mrb, hash);
 249   if (mrb_nil_p(block)) {
 250     if (argc > 0) {
 251       if (argc != 1) mrb_raise(mrb, E_ARGUMENT_ERROR, "wrong number of arguments");
 252       ifnone = argv[0];
 253     }
 254     else {
 255       ifnone = mrb_nil_value();
 256     }
 257   }
 258   else {
 259     if (argc > 0) {
 260       mrb_raise(mrb, E_ARGUMENT_ERROR, "wrong number of arguments");
 261     }
 262     RHASH(hash)->flags |= MRB_HASH_PROC_DEFAULT;
 263     ifnone = block;
 264   }
 265   mrb_iv_set(mrb, hash, mrb_intern2(mrb, "ifnone", 6), ifnone);
 266   return hash;
 267 }
 268
 269 /*
 270  *  call-seq:
 271  *     Hash[ key, value, ... ]         -> new_hash
 272  *     Hash[ [ [key, value], ... ] ]   -> new_hash
 273  *     Hash[ object ]                  -> new_hash
 274  *
 275  *  Creates a new hash populated with the given objects. Equivalent to
 276  *  the literal <code>{ <i>key</i> => <i>value</i>, ... }</code>. In the first
 277  *  form, keys and values occur in pairs, so there must be an even number of arguments.
 278  *  The second and third form take a single argument which is either
 279  *  an array of key-value pairs or an object convertible to a hash.
 280  *
 281  *     Hash["a", 100, "b", 200]             #=> {"a"=>100, "b"=>200}
 282  *     Hash[ [ ["a", 100], ["b", 200] ] ]   #=> {"a"=>100, "b"=>200}
 283  *     Hash["a" => 100, "b" => 200]         #=> {"a"=>100, "b"=>200}
 284  */
 285
 286 static mrb_value
 287 to_hash(mrb_state *mrb, mrb_value hash)
 288 {
 289   return mrb_convert_type(mrb, hash, MRB_TT_HASH, "Hash", "to_hash");
 290 }
 291
 292 /*
 293  *  call-seq:
 294  *     Hash.try_convert(obj) -> hash or nil
 295  *
 296  *  Try to convert <i>obj</i> into a hash, using to_hash method.
 297  *  Returns converted hash or nil if <i>obj</i> cannot be converted
 298  *  for any reason.
 299  *
 300  *     Hash.try_convert({1=>2})   # => {1=>2}
 301  *     Hash.try_convert("1=>2")   # => nil
 302  */
 303
 304 /* 15.2.13.4.2  */
 305 /*
 306  *  call-seq:
 307  *     hsh[key]    ->  value
 308  *
 309  *  Element Reference---Retrieves the <i>value</i> object corresponding
 310  *  to the <i>key</i> object. If not found, returns the default value (see
 311  *  <code>Hash::new</code> for details).
 312  *
 313  *     h = { "a" => 100, "b" => 200 }
 314  *     h["a"]   #=> 100
 315  *     h["c"]   #=> nil
 316  *
 317  */
 318 mrb_value
 319 mrb_hash_aget(mrb_state *mrb, mrb_value self)
 320 {
 321   mrb_value key;
 322
 323   mrb_get_args(mrb, "o", &key);
 324   return mrb_hash_get(mrb, self, key);
 325 }
 326
 327 mrb_value
 328 mrb_hash_lookup(mrb_state *mrb, mrb_value hash, mrb_value key)
 329 {
 330   return mrb_hash_get(mrb, hash, key);
 331 }
 332
 333 /*
 334  *  call-seq:
 335  *     hsh.fetch(key [, default] )       -> obj
 336  *     hsh.fetch(key) {| key | block }   -> obj
 337  *
 338  *  Returns a value from the hash for the given key. If the key can't be
 339  *  found, there are several options: With no other arguments, it will
 340  *  raise an <code>KeyError</code> exception; if <i>default</i> is
 341  *  given, then that will be returned; if the optional code block is
 342  *  specified, then that will be run and its result returned.
 343  *
 344  *     h = { "a" => 100, "b" => 200 }
 345  *     h.fetch("a")                            #=> 100
 346  *     h.fetch("z", "go fish")                 #=> "go fish"
 347  *     h.fetch("z") { |el| "go fish, #{el}"}   #=> "go fish, z"
 348  *
 349  *  The following example shows that an exception is raised if the key
 350  *  is not found and a default value is not supplied.
 351  *
 352  *     h = { "a" => 100, "b" => 200 }
 353  *     h.fetch("z")
 354  *
 355  *  <em>produces:</em>
 356  *
 357  *     prog.rb:2:in `fetch': key not found (KeyError)
 358  *      from prog.rb:2
 359  *
 360  */
 361
 362 /* 15.2.13.4.5  */
 363 /*
 364  *  call-seq:
 365  *     hsh.default(key=nil)   -> obj
 366  *
 367  *  Returns the default value, the value that would be returned by
 368  *  <i>hsh</i>[<i>key</i>] if <i>key</i> did not exist in <i>hsh</i>.
 369  *  See also <code>Hash::new</code> and <code>Hash#default=</code>.
 370  *
 371  *     h = Hash.new                            #=> {}
 372  *     h.default                               #=> nil
 373  *     h.default(2)                            #=> nil
 374  *
 375  *     h = Hash.new("cat")                     #=> {}
 376  *     h.default                               #=> "cat"
 377  *     h.default(2)                            #=> "cat"
 378  *
 379  *     h = Hash.new {|h,k| h[k] = k.to_i*10}   #=> {}
 380  *     h.default                               #=> nil
 381  *     h.default(2)                            #=> 20
 382  */
 383
 384 static mrb_value
 385 mrb_hash_default(mrb_state *mrb, mrb_value hash)
 386 {
 387   mrb_value *argv;
 388   int argc;
 389   mrb_value key;
 390
 391   mrb_get_args(mrb, "*", &argv, &argc);
 392   if (MRB_RHASH_PROCDEFAULT_P(hash)) {
 393     if (argc == 0) return mrb_nil_value();
 394     key = argv[0];
 395     return mrb_funcall(mrb, RHASH_PROCDEFAULT(hash), "call", 2, hash, key);
 396   }
 397   else {
 398     return RHASH_IFNONE(hash);
 399   }
 400 }
 401
 402 /* 15.2.13.4.6  */
 403 /*
 404  *  call-seq:
 405  *     hsh.default = obj     -> obj
 406  *
 407  *  Sets the default value, the value returned for a key that does not
 408  *  exist in the hash. It is not possible to set the default to a
 409  *  <code>Proc</code> that will be executed on each key lookup.
 410  *
 411  *     h = { "a" => 100, "b" => 200 }
 412  *     h.default = "Go fish"
 413  *     h["a"]     #=> 100
 414  *     h["z"]     #=> "Go fish"
 415  *     # This doesn't do what you might hope...
 416  *     h.default = proc do |hash, key|
 417  *       hash[key] = key + key
 418  *     end
 419  *     h[2]       #=> #<Proc:0x401b3948@-:6>
 420  *     h["cat"]   #=> #<Proc:0x401b3948@-:6>
 421  */
 422
 423 static mrb_value
 424 mrb_hash_set_default(mrb_state *mrb, mrb_value hash)
 425 {
 426   mrb_value ifnone;
 427
 428   mrb_get_args(mrb, "o", &ifnone);
 429   mrb_hash_modify(mrb, hash);
 430   mrb_iv_set(mrb, hash, mrb_intern2(mrb, "ifnone", 6), ifnone);
 431   RHASH(hash)->flags &= ~(MRB_HASH_PROC_DEFAULT);
 432
 433   return ifnone;
 434 }
 435
 436 /* 15.2.13.4.7  */
 437 /*
 438  *  call-seq:
 439  *     hsh.default_proc -> anObject
 440  *
 441  *  If <code>Hash::new</code> was invoked with a block, return that
 442  *  block, otherwise return <code>nil</code>.
 443  *
 444  *     h = Hash.new {|h,k| h[k] = k*k }   #=> {}
 445  *     p = h.default_proc                 #=> #<Proc:0x401b3d08@-:1>
 446  *     a = []                             #=> []
 447  *     p.call(a, 2)
 448  *     a                                  #=> [nil, nil, 4]
 449  */
 450
 451
 452 static mrb_value
 453 mrb_hash_default_proc(mrb_state *mrb, mrb_value hash)
 454 {
 455   if (MRB_RHASH_PROCDEFAULT_P(hash)) {
 456     return RHASH_PROCDEFAULT(hash);
 457   }
 458   return mrb_nil_value();
 459 }
 460
 461 /*
 462  *  call-seq:
 463  *     hsh.default_proc = proc_obj     -> proc_obj
 464  *
 465  *  Sets the default proc to be executed on each key lookup.
 466  *
 467  *     h.default_proc = proc do |hash, key|
 468  *       hash[key] = key + key
 469  *     end
 470  *     h[2]       #=> 4
 471  *     h["cat"]   #=> "catcat"
 472  */
 473
 474 static mrb_value
 475 mrb_hash_set_default_proc(mrb_state *mrb, mrb_value hash)
 476 {
 477   mrb_value ifnone;
 478
 479   mrb_get_args(mrb, "o", &ifnone);
 480   mrb_hash_modify(mrb, hash);
 481   mrb_iv_set(mrb, hash, mrb_intern2(mrb, "ifnone", 6), ifnone);
 482   RHASH(hash)->flags |= MRB_HASH_PROC_DEFAULT;
 483
 484   return ifnone;
 485 }
 486
 487 mrb_value
 488 mrb_hash_delete_key(mrb_state *mrb, mrb_value hash, mrb_value key)
 489 {
 490   khash_t(ht) *h = RHASH_TBL(hash);
 491   khiter_t k;
 492   mrb_value delVal;
 493
 494   if (h) {
 495     k = kh_get(ht, h, key);
 496     if (k != kh_end(h)) {
 497       delVal = kh_value(h, k);
 498       kh_del(ht, h, k);
 499       return delVal;
 500     }
 501   }
 502
 503   /* not found */
 504   return mrb_nil_value();
 505 }
 506
 507 /* 15.2.13.4.8  */
 508 /*
 509  *  call-seq:
 510  *     hsh.delete(key)                   -> value
 511  *     hsh.delete(key) {| key | block }  -> value
 512  *
 513  *  Deletes and returns a key-value pair from <i>hsh</i> whose key is
 514  *  equal to <i>key</i>. If the key is not found, returns the
 515  *  <em>default value</em>. If the optional code block is given and the
 516  *  key is not found, pass in the key and return the result of
 517  *  <i>block</i>.
 518  *
 519  *     h = { "a" => 100, "b" => 200 }
 520  *     h.delete("a")                              #=> 100
 521  *     h.delete("z")                              #=> nil
 522  *     h.delete("z") { |el| "#{el} not found" }   #=> "z not found"
 523  *
 524  */
 525 mrb_value
 526 mrb_hash_delete(mrb_state *mrb, mrb_value self)
 527 {
 528   mrb_value key;
 529
 530   mrb_get_args(mrb, "o", &key);
 531   return mrb_hash_delete_key(mrb, self, key);
 532 }
 533
 534 /* 15.2.13.4.24 */
 535 /*
 536  *  call-seq:
 537  *     hsh.shift -> anArray or obj
 538  *
 539  *  Removes a key-value pair from <i>hsh</i> and returns it as the
 540  *  two-item array <code>[</code> <i>key, value</i> <code>]</code>, or
 541  *  the hash's default value if the hash is empty.
 542  *
 543  *     h = { 1 => "a", 2 => "b", 3 => "c" }
 544  *     h.shift   #=> [1, "a"]
 545  *     h         #=> {2=>"b", 3=>"c"}
 546  */
 547
 548 static mrb_value
 549 mrb_hash_shift(mrb_state *mrb, mrb_value hash)
 550 {
 551   khash_t(ht) *h = RHASH_TBL(hash);
 552   khiter_t k;
 553   mrb_value delKey, delVal;
 554
 555   mrb_hash_modify(mrb, hash);
 556   if (h) {
 557     if (kh_size(h) > 0) {
 558       for (k = kh_begin(h); k != kh_end(h); k++) {
 559         if (!kh_exist(h,k)) continue;
 560
 561         delKey = kh_key(h,k);
 562         mrb_gc_protect(mrb, delKey);
 563         delVal = mrb_hash_delete_key(mrb, hash, delKey);
 564         mrb_gc_protect(mrb, delVal);
 565
 566         return mrb_assoc_new(mrb, delKey, delVal);
 567       }
 568     }
 569   }
 570
 571   if (MRB_RHASH_PROCDEFAULT_P(hash)) {
 572     return mrb_funcall(mrb, RHASH_PROCDEFAULT(hash), "call", 2, hash, mrb_nil_value());
 573   }
 574   else {
 575     return RHASH_IFNONE(hash);
 576   }
 577 }
 578
 579 /*
 580  *  call-seq:
 581  *     hsh.delete_if {| key, value | block }  -> hsh
 582  *     hsh.delete_if                          -> an_enumerator
 583  *
 584  *  Deletes every key-value pair from <i>hsh</i> for which <i>block</i>
 585  *  evaluates to <code>true</code>.
 586  *
 587  *  If no block is given, an enumerator is returned instead.
 588  *
 589  *     h = { "a" => 100, "b" => 200, "c" => 300 }
 590  *     h.delete_if {|key, value| key >= "b" }   #=> {"a"=>100}
 591  *
 592  */
 593
 594 /*
 595  *  call-seq:
 596  *     hsh.reject! {| key, value | block }  -> hsh or nil
 597  *     hsh.reject!                          -> an_enumerator
 598  *
 599  *  Equivalent to <code>Hash#delete_if</code>, but returns
 600  *  <code>nil</code> if no changes were made.
 601  */
 602
 603 /*
 604  *  call-seq:
 605  *     hsh.reject {| key, value | block }  -> a_hash
 606  *
 607  *  Same as <code>Hash#delete_if</code>, but works on (and returns) a
 608  *  copy of the <i>hsh</i>. Equivalent to
 609  *  <code><i>hsh</i>.dup.delete_if</code>.
 610  *
 611  */
 612
 613 /*
 614  * call-seq:
 615  *   hsh.values_at(key, ...)   -> array
 616  *
 617  * Return an array containing the values associated with the given keys.
 618  * Also see <code>Hash.select</code>.
 619  *
 620  *   h = { "cat" => "feline", "dog" => "canine", "cow" => "bovine" }
 621  *   h.values_at("cow", "cat")  #=> ["bovine", "feline"]
 622  */
 623
 624 mrb_value
 625 mrb_hash_values_at(mrb_state *mrb, int argc, mrb_value *argv, mrb_value hash)
 626 {
 627     mrb_value result = mrb_ary_new_capa(mrb, argc);
 628     long i;
 629
 630     for (i=0; i<argc; i++) {
 631         mrb_ary_push(mrb, result, mrb_hash_get(mrb, hash, argv[i]));
 632     }
 633     return result;
 634 }
 635
 636 /*
 637  *  call-seq:
 638  *     hsh.select {|key, value| block}   -> a_hash
 639  *     hsh.select                        -> an_enumerator
 640  *
 641  *  Returns a new hash consisting of entries for which the block returns true.
 642  *
 643  *  If no block is given, an enumerator is returned instead.
 644  *
 645  *     h = { "a" => 100, "b" => 200, "c" => 300 }
 646  *     h.select {|k,v| k > "a"}  #=> {"b" => 200, "c" => 300}
 647  *     h.select {|k,v| v < 200}  #=> {"a" => 100}
 648  */
 649
 650 /*
 651  *  call-seq:
 652  *     hsh.select! {| key, value | block }  -> hsh or nil
 653  *     hsh.select!                          -> an_enumerator
 654  *
 655  *  Equivalent to <code>Hash#keep_if</code>, but returns
 656  *  <code>nil</code> if no changes were made.
 657  */
 658
 659 /*
 660  *  call-seq:
 661  *     hsh.keep_if {| key, value | block }  -> hsh
 662  *     hsh.keep_if                          -> an_enumerator
 663  *
 664  *  Deletes every key-value pair from <i>hsh</i> for which <i>block</i>
 665  *  evaluates to false.
 666  *
 667  *  If no block is given, an enumerator is returned instead.
 668  *
 669  */
 670
 671 /* 15.2.13.4.4  */
 672 /*
 673  *  call-seq:
 674  *     hsh.clear -> hsh
 675  *
 676  *  Removes all key-value pairs from <i>hsh</i>.
 677  *
 678  *     h = { "a" => 100, "b" => 200 }   #=> {"a"=>100, "b"=>200}
 679  *     h.clear                          #=> {}
 680  *
 681  */
 682
 683 static mrb_value
 684 mrb_hash_clear(mrb_state *mrb, mrb_value hash)
 685 {
 686   khash_t(ht) *h = RHASH_TBL(hash);
 687
 688   if (h) kh_clear(ht, h);
 689   return hash;
 690 }
 691
 692 /* 15.2.13.4.3  */
 693 /* 15.2.13.4.26 */
 694 /*
 695  *  call-seq:
 696  *     hsh[key] = value        -> value
 697  *     hsh.store(key, value)   -> value
 698  *
 699  *  Element Assignment---Associates the value given by
 700  *  <i>value</i> with the key given by <i>key</i>.
 701  *  <i>key</i> should not have its value changed while it is in
 702  *  use as a key (a <code>String</code> passed as a key will be
 703  *  duplicated and frozen).
 704  *
 705  *     h = { "a" => 100, "b" => 200 }
 706  *     h["a"] = 9
 707  *     h["c"] = 4
 708  *     h   #=> {"a"=>9, "b"=>200, "c"=>4}
 709  *
 710  */
 711 mrb_value
 712 mrb_hash_aset(mrb_state *mrb, mrb_value self)
 713 {
 714   mrb_value key, val;
 715
 716   mrb_get_args(mrb, "oo", &key, &val);
 717   mrb_hash_set(mrb, self, key, val);
 718   return val;
 719 }
 720
 721 /* 15.2.13.4.17 */
 722 /* 15.2.13.4.23 */
 723 /*
 724  *  call-seq:
 725  *     hsh.replace(other_hash) -> hsh
 726  *
 727  *  Replaces the contents of <i>hsh</i> with the contents of
 728  *  <i>other_hash</i>.
 729  *
 730  *     h = { "a" => 100, "b" => 200 }
 731  *     h.replace({ "c" => 300, "d" => 400 })   #=> {"c"=>300, "d"=>400}
 732  *
 733  */
 734
 735 static mrb_value
 736 mrb_hash_replace(mrb_state *mrb, mrb_value hash)
 737 {
 738   mrb_value hash2, ifnone;
 739   khash_t(ht) *h2;
 740   khiter_t k;
 741
 742   mrb_get_args(mrb, "o", &hash2);
 743   hash2 = to_hash(mrb, hash2);
 744   if (mrb_obj_equal(mrb, hash, hash2)) return hash;
 745   mrb_hash_clear(mrb, hash);
 746
 747   h2 = RHASH_TBL(hash2);
 748   if (h2) {
 749     for (k = kh_begin(h2); k != kh_end(h2); k++) {
 750       if (kh_exist(h2, k))
 751         mrb_hash_set(mrb, hash, kh_key(h2, k), kh_value(h2, k));
 752     }
 753   }
 754
 755   if (MRB_RHASH_PROCDEFAULT_P(hash2)) {
 756     RHASH(hash)->flags |= MRB_HASH_PROC_DEFAULT;
 757     ifnone = RHASH_PROCDEFAULT(hash2);
 758   }
 759   else {
 760     ifnone = RHASH_IFNONE(hash2);
 761   }
 762   mrb_iv_set(mrb, hash, mrb_intern2(mrb, "ifnone", 6), ifnone);
 763
 764   return hash;
 765 }
 766
 767 /* 15.2.13.4.20 */
 768 /* 15.2.13.4.25 */
 769 /*
 770  *  call-seq:
 771  *     hsh.length    ->  fixnum
 772  *     hsh.size      ->  fixnum
 773  *
 774  *  Returns the number of key-value pairs in the hash.
 775  *
 776  *     h = { "d" => 100, "a" => 200, "v" => 300, "e" => 400 }
 777  *     h.length        #=> 4
 778  *     h.delete("a")   #=> 200
 779  *     h.length        #=> 3
 780  */
 781 static mrb_value
 782 mrb_hash_size_m(mrb_state *mrb, mrb_value self)
 783 {
 784   khash_t(ht) *h = RHASH_TBL(self);
 785
 786   if (!h) return mrb_fixnum_value(0);
 787   return mrb_fixnum_value(kh_size(h));
 788 }
 789
 790 /* 15.2.13.4.12 */
 791 /*
 792  *  call-seq:
 793  *     hsh.empty?    -> true or false
 794  *
 795  *  Returns <code>true</code> if <i>hsh</i> contains no key-value pairs.
 796  *
 797  *     {}.empty?   #=> true
 798  *
 799  */
 800 static mrb_value
 801 mrb_hash_empty_p(mrb_state *mrb, mrb_value self)
 802 {
 803   khash_t(ht) *h = RHASH_TBL(self);
 804   mrb_bool empty_p;
 805
 806   if (h) {
 807     empty_p = (kh_size(h) == 0);
 808   }
 809   else {
 810     empty_p = 1;
 811   }
 812
 813   return mrb_bool_value(empty_p);
 814 }
 815
 816 /* 15.2.13.4.11 */
 817 /*
 818  *  call-seq:
 819  *     hsh.each_value {| value | block } -> hsh
 820  *     hsh.each_value                    -> an_enumerator
 821  *
 822  *  Calls <i>block</i> once for each key in <i>hsh</i>, passing the
 823  *  value as a parameter.
 824  *
 825  *  If no block is given, an enumerator is returned instead.
 826  *
 827  *     h = { "a" => 100, "b" => 200 }
 828  *     h.each_value {|value| puts value }
 829  *
 830  *  <em>produces:</em>
 831  *
 832  *     100
 833  *     200
 834  */
 835
 836 /* 15.2.13.4.10 */
 837 /*
 838  *  call-seq:
 839  *     hsh.each_key {| key | block } -> hsh
 840  *     hsh.each_key                  -> an_enumerator
 841  *
 842  *  Calls <i>block</i> once for each key in <i>hsh</i>, passing the key
 843  *  as a parameter.
 844  *
 845  *  If no block is given, an enumerator is returned instead.
 846  *
 847  *     h = { "a" => 100, "b" => 200 }
 848  *     h.each_key {|key| puts key }
 849  *
 850  *  <em>produces:</em>
 851  *
 852  *     a
 853  *     b
 854  */
 855
 856 /* 15.2.13.4.9  */
 857 /*
 858  *  call-seq:
 859  *     hsh.each      {| key, value | block } -> hsh
 860  *     hsh.each_pair {| key, value | block } -> hsh
 861  *     hsh.each                              -> an_enumerator
 862  *     hsh.each_pair                         -> an_enumerator
 863  *
 864  *  Calls <i>block</i> once for each key in <i>hsh</i>, passing the key-value
 865  *  pair as parameters.
 866  *
 867  *  If no block is given, an enumerator is returned instead.
 868  *
 869  *     h = { "a" => 100, "b" => 200 }
 870  *     h.each {|key, value| puts "#{key} is #{value}" }
 871  *
 872  *  <em>produces:</em>
 873  *
 874  *     a is 100
 875  *     b is 200
 876  *
 877  */
 878
 879 static mrb_value
 880 inspect_hash(mrb_state *mrb, mrb_value hash, int recur)
 881 {
 882   mrb_value str, str2;
 883   khash_t(ht) *h = RHASH_TBL(hash);
 884   khiter_t k;
 885
 886   if (recur) return mrb_str_new(mrb, "{...}", 5);
 887
 888   str = mrb_str_new(mrb, "{", 1);
 889   if (h && kh_size(h) > 0) {
 890     for (k = kh_begin(h); k != kh_end(h); k++) {
 891       int ai;
 892
 893       if (!kh_exist(h,k)) continue;
 894
 895       ai = mrb_gc_arena_save(mrb);
 896
 897       if (RSTRING_LEN(str) > 1) mrb_str_cat2(mrb, str, ", ");
 898
 899       str2 = mrb_inspect(mrb, kh_key(h,k));
 900       mrb_str_append(mrb, str, str2);
 901       mrb_str_buf_cat(mrb, str, "=>", 2);
 902       str2 = mrb_inspect(mrb, kh_value(h,k));
 903       mrb_str_append(mrb, str, str2);
 904
 905       mrb_gc_arena_restore(mrb, ai);
 906     }
 907   }
 908   mrb_str_buf_cat(mrb, str, "}", 1);
 909
 910   return str;
 911 }
 912
 913 /* 15.2.13.4.30 (x)*/
 914 /*
 915  * call-seq:
 916  *   hsh.to_s     -> string
 917  *   hsh.inspect  -> string
 918  *
 919  * Return the contents of this hash as a string.
 920  *
 921  *     h = { "c" => 300, "a" => 100, "d" => 400, "c" => 300  }
 922  *     h.to_s   #=> "{\"c\"=>300, \"a\"=>100, \"d\"=>400}"
 923  */
 924
 925 static mrb_value
 926 mrb_hash_inspect(mrb_state *mrb, mrb_value hash)
 927 {
 928   khash_t(ht) *h = RHASH_TBL(hash);
 929
 930   if (!h || kh_size(h) == 0)
 931     return mrb_str_new(mrb, "{}", 2);
 932   return inspect_hash(mrb, hash, 0);
 933 }
 934
 935 /* 15.2.13.4.29 (x)*/
 936 /*
 937  * call-seq:
 938  *    hsh.to_hash   => hsh
 939  *
 940  * Returns +self+.
 941  */
 942
 943 static mrb_value
 944 mrb_hash_to_hash(mrb_state *mrb, mrb_value hash)
 945 {
 946     return hash;
 947 }
 948
 949 /* 15.2.13.4.19 */
 950 /*
 951  *  call-seq:
 952  *     hsh.keys    -> array
 953  *
 954  *  Returns a new array populated with the keys from this hash. See also
 955  *  <code>Hash#values</code>.
 956  *
 957  *     h = { "a" => 100, "b" => 200, "c" => 300, "d" => 400 }
 958  *     h.keys   #=> ["a", "b", "c", "d"]
 959  *
 960  */
 961
 962 mrb_value
 963 mrb_hash_keys(mrb_state *mrb, mrb_value hash)
 964 {
 965   khash_t(ht) *h = RHASH_TBL(hash);
 966   khiter_t k;
 967   mrb_value ary;
 968
 969   if (!h) return mrb_ary_new(mrb);
 970   ary = mrb_ary_new_capa(mrb, kh_size(h));
 971   for (k = kh_begin(h); k != kh_end(h); k++) {
 972     if (kh_exist(h, k)) {
 973       mrb_value v = kh_key(h,k);
 974       mrb_ary_push(mrb, ary, v);
 975     }
 976   }
 977   return ary;
 978 }
 979
 980 /* 15.2.13.4.28 */
 981 /*
 982  *  call-seq:
 983  *     hsh.values    -> array
 984  *
 985  *  Returns a new array populated with the values from <i>hsh</i>. See
 986  *  also <code>Hash#keys</code>.
 987  *
 988  *     h = { "a" => 100, "b" => 200, "c" => 300 }
 989  *     h.values   #=> [100, 200, 300]
 990  *
 991  */
 992
 993 static mrb_value
 994 mrb_hash_values(mrb_state *mrb, mrb_value hash)
 995 {
 996   khash_t(ht) *h = RHASH_TBL(hash);
 997   khiter_t k;
 998   mrb_value ary;
 999
1000   if (!h) return mrb_ary_new(mrb);
1001   ary = mrb_ary_new_capa(mrb, kh_size(h));
1002   for (k = kh_begin(h); k != kh_end(h); k++) {
1003     if (kh_exist(h, k)){
1004       mrb_value v = kh_value(h,k);
1005       mrb_ary_push(mrb, ary, v);
1006     }
1007   }
1008   return ary;
1009 }
1010
1011 static mrb_value
1012 mrb_hash_has_keyWithKey(mrb_state *mrb, mrb_value hash, mrb_value key)
1013 {
1014   khash_t(ht) *h = RHASH_TBL(hash);
1015   khiter_t k;
1016   mrb_bool result;
1017
1018   if (h) {
1019     k = kh_get(ht, h, key);
1020     result = (k != kh_end(h));
1021   }
1022   else {
1023     result = 0;
1024   }
1025
1026   return mrb_bool_value(result);
1027 }
1028
1029 /* 15.2.13.4.13 */
1030 /* 15.2.13.4.15 */
1031 /* 15.2.13.4.18 */
1032 /* 15.2.13.4.21 */
1033 /*
1034  *  call-seq:
1035  *     hsh.has_key?(key)    -> true or false
1036  *     hsh.include?(key)    -> true or false
1037  *     hsh.key?(key)        -> true or false
1038  *     hsh.member?(key)     -> true or false
1039  *
1040  *  Returns <code>true</code> if the given key is present in <i>hsh</i>.
1041  *
1042  *     h = { "a" => 100, "b" => 200 }
1043  *     h.has_key?("a")   #=> true
1044  *     h.has_key?("z")   #=> false
1045  *
1046  */
1047
1048 static mrb_value
1049 mrb_hash_has_key(mrb_state *mrb, mrb_value hash)
1050 {
1051   mrb_value key;
1052
1053   mrb_get_args(mrb, "o", &key);
1054   return mrb_hash_has_keyWithKey(mrb, hash, key);
1055 }
1056
1057 static mrb_value
1058 mrb_hash_has_valueWithvalue(mrb_state *mrb, mrb_value hash, mrb_value value)
1059 {
1060   khash_t(ht) *h = RHASH_TBL(hash);
1061   khiter_t k;
1062
1063   if (h) {
1064     for (k = kh_begin(h); k != kh_end(h); k++) {
1065       if (!kh_exist(h, k)) continue;
1066
1067       if (mrb_equal(mrb, kh_value(h,k), value)) {
1068         return mrb_true_value();
1069       }
1070     }
1071   }
1072
1073   return mrb_false_value();
1074 }
1075
1076 /* 15.2.13.4.14 */
1077 /* 15.2.13.4.27 */
1078 /*
1079  *  call-seq:
1080  *     hsh.has_value?(value)    -> true or false
1081  *     hsh.value?(value)        -> true or false
1082  *
1083  *  Returns <code>true</code> if the given value is present for some key
1084  *  in <i>hsh</i>.
1085  *
1086  *     h = { "a" => 100, "b" => 200 }
1087  *     h.has_value?(100)   #=> true
1088  *     h.has_value?(999)   #=> false
1089  */
1090
1091 static mrb_value
1092 mrb_hash_has_value(mrb_state *mrb, mrb_value hash)
1093 {
1094   mrb_value val;
1095
1096   mrb_get_args(mrb, "o", &val);
1097   return mrb_hash_has_valueWithvalue(mrb, hash, val);
1098 }
1099
1100 static mrb_value
1101 hash_equal(mrb_state *mrb, mrb_value hash1, mrb_value hash2, int eql)
1102 {
1103   khash_t(ht) *h1, *h2;
1104
1105   if (mrb_obj_equal(mrb, hash1, hash2)) return mrb_true_value();
1106   if (!mrb_hash_p(hash2)) {
1107       if (!mrb_respond_to(mrb, hash2, mrb_intern2(mrb, "to_hash", 7))) {
1108           return mrb_false_value();
1109       }
1110       if (eql)
1111           return mrb_fixnum_value(mrb_eql(mrb, hash2, hash1));
1112       else
1113           return mrb_fixnum_value(mrb_equal(mrb, hash2, hash1));
1114   }
1115   h1 = RHASH_TBL(hash1);
1116   h2 = RHASH_TBL(hash2);
1117   if (!h1) {
1118     return mrb_bool_value(!h2);
1119   }
1120   if (!h2) return mrb_false_value();
1121   if (kh_size(h1) != kh_size(h2)) return mrb_false_value();
1122   else {
1123     khiter_t k1, k2;
1124     mrb_value key;
1125
1126     for (k1 = kh_begin(h1); k1 != kh_end(h1); k1++) {
1127       if (!kh_exist(h1, k1)) continue;
1128       key = kh_key(h1,k1);
1129       k2 = kh_get(ht, h2, key);
1130       if (k2 != kh_end(h2)) {
1131         if (mrb_equal(mrb, kh_value(h1,k1), kh_value(h2,k2))) {
1132           continue; /* next key */
1133         }
1134       }
1135       return mrb_false_value();
1136     }
1137   }
1138   return mrb_true_value();
1139 }
1140
1141 /* 15.2.13.4.1  */
1142 /*
1143  *  call-seq:
1144  *     hsh == other_hash    -> true or false
1145  *
1146  *  Equality---Two hashes are equal if they each contain the same number
1147  *  of keys and if each key-value pair is equal to (according to
1148  *  <code>Object#==</code>) the corresponding elements in the other
1149  *  hash.
1150  *
1151  *     h1 = { "a" => 1, "c" => 2 }
1152  *     h2 = { 7 => 35, "c" => 2, "a" => 1 }
1153  *     h3 = { "a" => 1, "c" => 2, 7 => 35 }
1154  *     h4 = { "a" => 1, "d" => 2, "f" => 35 }
1155  *     h1 == h2   #=> false
1156  *     h2 == h3   #=> true
1157  *     h3 == h4   #=> false
1158  *
1159  */
1160
1161 static mrb_value
1162 mrb_hash_equal(mrb_state *mrb, mrb_value hash1)
1163 {
1164   mrb_value hash2;
1165
1166   mrb_get_args(mrb, "o", &hash2);
1167   return hash_equal(mrb, hash1, hash2, FALSE);
1168 }
1169
1170 /* 15.2.13.4.32 (x)*/
1171 /*
1172  *  call-seq:
1173  *     hash.eql?(other)  -> true or false
1174  *
1175  *  Returns <code>true</code> if <i>hash</i> and <i>other</i> are
1176  *  both hashes with the same content.
1177  */
1178
1179 static mrb_value
1180 mrb_hash_eql(mrb_state *mrb, mrb_value hash1)
1181 {
1182   mrb_value hash2;
1183
1184   mrb_get_args(mrb, "o", &hash2);
1185   return hash_equal(mrb, hash1, hash2, TRUE);
1186 }
1187
1188 /*
1189  *  call-seq:
1190  *     hsh.merge!(other_hash)                                 -> hsh
1191  *     hsh.update(other_hash)                                 -> hsh
1192  *     hsh.merge!(other_hash){|key, oldval, newval| block}    -> hsh
1193  *     hsh.update(other_hash){|key, oldval, newval| block}    -> hsh
1194  *
1195  *  Adds the contents of <i>other_hash</i> to <i>hsh</i>.  If no
1196  *  block is specified, entries with duplicate keys are overwritten
1197  *  with the values from <i>other_hash</i>, otherwise the value
1198  *  of each duplicate key is determined by calling the block with
1199  *  the key, its value in <i>hsh</i> and its value in <i>other_hash</i>.
1200  *
1201  *     h1 = { "a" => 100, "b" => 200 }
1202  *     h2 = { "b" => 254, "c" => 300 }
1203  *     h1.merge!(h2)   #=> {"a"=>100, "b"=>254, "c"=>300}
1204  *
1205  *     h1 = { "a" => 100, "b" => 200 }
1206  *     h2 = { "b" => 254, "c" => 300 }
1207  *     h1.merge!(h2) { |key, v1, v2| v1 }
1208  *                     #=> {"a"=>100, "b"=>200, "c"=>300}
1209  */
1210
1211 /* 15.2.13.4.22 */
1212 /*
1213  *  call-seq:
1214  *     hsh.merge(other_hash)                              -> new_hash
1215  *     hsh.merge(other_hash){|key, oldval, newval| block} -> new_hash
1216  *
1217  *  Returns a new hash containing the contents of <i>other_hash</i> and
1218  *  the contents of <i>hsh</i>. If no block is specified, the value for
1219  *  entries with duplicate keys will be that of <i>other_hash</i>. Otherwise
1220  *  the value for each duplicate key is determined by calling the block
1221  *  with the key, its value in <i>hsh</i> and its value in <i>other_hash</i>.
1222  *
1223  *     h1 = { "a" => 100, "b" => 200 }
1224  *     h2 = { "b" => 254, "c" => 300 }
1225  *     h1.merge(h2)   #=> {"a"=>100, "b"=>254, "c"=>300}
1226  *     h1.merge(h2){|key, oldval, newval| newval - oldval}
1227  *                    #=> {"a"=>100, "b"=>54,  "c"=>300}
1228  *     h1             #=> {"a"=>100, "b"=>200}
1229  *
1230  */
1231
1232 /*
1233  *  call-seq:
1234  *     hash.assoc(obj)   ->  an_array  or  nil
1235  *
1236  *  Searches through the hash comparing _obj_ with the key using <code>==</code>.
1237  *  Returns the key-value pair (two elements array) or +nil+
1238  *  if no match is found.  See <code>Array#assoc</code>.
1239  *
1240  *     h = {"colors"  => ["red", "blue", "green"],
1241  *          "letters" => ["a", "b", "c" ]}
1242  *     h.assoc("letters")  #=> ["letters", ["a", "b", "c"]]
1243  *     h.assoc("foo")      #=> nil
1244  */
1245
1246 mrb_value
1247 mrb_hash_assoc(mrb_state *mrb, mrb_value hash)
1248 {
1249   mrb_value key, value, has_key;
1250
1251   mrb_get_args(mrb, "o", &key);
1252   if (mrb_nil_p(key))
1253     mrb_raise(mrb, E_ARGUMENT_ERROR, "wrong number of arguments");
1254
1255   has_key = mrb_hash_has_keyWithKey(mrb, hash, key);
1256   if (mrb_test(has_key)) {
1257     value = mrb_hash_get(mrb, hash, key);
1258     return mrb_assoc_new(mrb, key, value);
1259   }
1260   else {
1261     return mrb_nil_value();
1262   }
1263 }
1264
1265 /*
1266  *  call-seq:
1267  *     hash.rassoc(key) -> an_array or nil
1268  *
1269  *  Searches through the hash comparing _obj_ with the value using <code>==</code>.
1270  *  Returns the first key-value pair (two-element array) that matches. See
1271  *  also <code>Array#rassoc</code>.
1272  *
1273  *     a = {1=> "one", 2 => "two", 3 => "three", "ii" => "two"}
1274  *     a.rassoc("two")    #=> [2, "two"]
1275  *     a.rassoc("four")   #=> nil
1276  */
1277
1278 mrb_value
1279 mrb_hash_rassoc(mrb_state *mrb, mrb_value hash)
1280 {
1281   mrb_value key, value, has_key;
1282
1283   mrb_get_args(mrb, "o", &key);
1284   has_key = mrb_hash_has_keyWithKey(mrb, hash, key);
1285   if (mrb_test(has_key)) {
1286     value = mrb_hash_get(mrb, hash, key);
1287     return mrb_assoc_new(mrb, value, key);
1288   }
1289   else {
1290     return mrb_nil_value();
1291   }
1292 }
1293
1294 /*
1295  *  call-seq:
1296  *     hash.flatten -> an_array
1297  *     hash.flatten(level) -> an_array
1298  *
1299  *  Returns a new array that is a one-dimensional flattening of this
1300  *  hash. That is, for every key or value that is an array, extract
1301  *  its elements into the new array.  Unlike Array#flatten, this
1302  *  method does not flatten recursively by default.  The optional
1303  *  <i>level</i> argument determines the level of recursion to flatten.
1304  *
1305  *     a =  {1=> "one", 2 => [2,"two"], 3 => "three"}
1306  *     a.flatten    # => [1, "one", 2, [2, "two"], 3, "three"]
1307  *     a.flatten(2) # => [1, "one", 2, 2, "two", 3, "three"]
1308  */
1309
1310 /*
1311  *  A <code>Hash</code> is a collection of key-value pairs. It is
1312  *  similar to an <code>Array</code>, except that indexing is done via
1313  *  arbitrary keys of any object type, not an integer index. Hashes enumerate
1314  *  their values in the order that the corresponding keys were inserted.
1315  *
1316  *  Hashes have a <em>default value</em> that is returned when accessing
1317  *  keys that do not exist in the hash. By default, that value is
1318  *  <code>nil</code>.
1319  *
1320  */
1321
1322 void
1323 mrb_init_hash(mrb_state *mrb)
1324 {
1325   struct RClass *h;
1326
1327   h = mrb->hash_class = mrb_define_class(mrb, "Hash", mrb->object_class);
1328   MRB_SET_INSTANCE_TT(h, MRB_TT_HASH);
1329
1330   mrb_include_module(mrb, h, mrb_class_get(mrb, "Enumerable"));
1331   mrb_define_method(mrb, h, "==",              mrb_hash_equal,       ARGS_REQ(1)); /* 15.2.13.4.1  */
1332   mrb_define_method(mrb, h, "[]",              mrb_hash_aget,        ARGS_REQ(1)); /* 15.2.13.4.2  */
1333   mrb_define_method(mrb, h, "[]=",             mrb_hash_aset,        ARGS_REQ(2)); /* 15.2.13.4.3  */
1334   mrb_define_method(mrb, h, "clear",           mrb_hash_clear,       ARGS_NONE()); /* 15.2.13.4.4  */
1335   mrb_define_method(mrb, h, "default",         mrb_hash_default,     ARGS_ANY());  /* 15.2.13.4.5  */
1336   mrb_define_method(mrb, h, "default=",        mrb_hash_set_default, ARGS_REQ(1)); /* 15.2.13.4.6  */
1337   mrb_define_method(mrb, h, "default_proc",    mrb_hash_default_proc,ARGS_NONE()); /* 15.2.13.4.7  */
1338   mrb_define_method(mrb, h, "default_proc=",   mrb_hash_set_default_proc,ARGS_REQ(1)); /* 15.2.13.4.7  */
1339   mrb_define_method(mrb, h, "__delete",        mrb_hash_delete,      ARGS_REQ(1)); /* core of 15.2.13.4.8  */
1340 // "each"                                                                             15.2.13.4.9  move to mrblib/hash.rb
1341 // "each_key"                                                                         15.2.13.4.10 move to mrblib/hash.rb
1342 // "each_value"                                                                       15.2.13.4.11 move to mrblib/hash.rb
1343   mrb_define_method(mrb, h, "empty?",          mrb_hash_empty_p,     ARGS_NONE()); /* 15.2.13.4.12 */
1344   mrb_define_method(mrb, h, "has_key?",        mrb_hash_has_key,     ARGS_REQ(1)); /* 15.2.13.4.13 */
1345   mrb_define_method(mrb, h, "has_value?",      mrb_hash_has_value,   ARGS_REQ(1)); /* 15.2.13.4.14 */
1346   mrb_define_method(mrb, h, "include?",        mrb_hash_has_key,     ARGS_REQ(1)); /* 15.2.13.4.15 */
1347   mrb_define_method(mrb, h, "__init_core",     mrb_hash_init_core,   ARGS_ANY());  /* core of 15.2.13.4.16 */
1348   mrb_define_method(mrb, h, "initialize_copy", mrb_hash_replace,     ARGS_REQ(1)); /* 15.2.13.4.17 */
1349   mrb_define_method(mrb, h, "key?",            mrb_hash_has_key,     ARGS_REQ(1)); /* 15.2.13.4.18 */
1350   mrb_define_method(mrb, h, "keys",            mrb_hash_keys,        ARGS_NONE()); /* 15.2.13.4.19 */
1351   mrb_define_method(mrb, h, "length",          mrb_hash_size_m,      ARGS_NONE()); /* 15.2.13.4.20 */
1352   mrb_define_method(mrb, h, "member?",         mrb_hash_has_key,     ARGS_REQ(1)); /* 15.2.13.4.21 */
1353 // "merge"                                                                            15.2.13.4.22 move to mrblib/hash.rb
1354   mrb_define_method(mrb, h, "replace",         mrb_hash_replace,     ARGS_REQ(1)); /* 15.2.13.4.23 */
1355   mrb_define_method(mrb, h, "shift",           mrb_hash_shift,       ARGS_NONE()); /* 15.2.13.4.24 */
1356   mrb_define_method(mrb, h, "size",            mrb_hash_size_m,      ARGS_NONE()); /* 15.2.13.4.25 */
1357   mrb_define_method(mrb, h, "store",           mrb_hash_aset,        ARGS_REQ(2)); /* 15.2.13.4.26 */
1358   mrb_define_method(mrb, h, "value?",          mrb_hash_has_value,   ARGS_REQ(1)); /* 15.2.13.4.27 */
1359   mrb_define_method(mrb, h, "values",          mrb_hash_values,      ARGS_NONE()); /* 15.2.13.4.28 */
1360
1361   mrb_define_method(mrb, h, "to_hash",         mrb_hash_to_hash,     ARGS_NONE()); /* 15.2.13.4.29 (x)*/
1362   mrb_define_method(mrb, h, "inspect",         mrb_hash_inspect,     ARGS_NONE()); /* 15.2.13.4.30 (x)*/
1363   mrb_define_alias(mrb,  h, "to_s",            "inspect");                         /* 15.2.13.4.31 (x)*/
1364   mrb_define_method(mrb, h, "eql?",            mrb_hash_eql,         ARGS_REQ(1)); /* 15.2.13.4.32 (x)*/
1365 }