2 ** random.c - Random module
4 ** See Copyright Notice in mruby.h
8 #include <mruby/variable.h>
9 #include <mruby/class.h>
10 #include <mruby/data.h>
11 #include <mruby/array.h>
12 #include "mt19937ar.h"
16 static char const MT_STATE_KEY[] = "$mrb_i_mt_state";
18 static const struct mrb_data_type mt_state_type = {
19 MT_STATE_KEY, mrb_free,
22 static mrb_value mrb_random_rand(mrb_state *mrb, mrb_value self);
23 static mrb_value mrb_random_srand(mrb_state *mrb, mrb_value self);
26 mt_srand(mt_state *t, unsigned long seed)
28 mrb_random_init_genrand(t, seed);
34 return mrb_random_genrand_int32(t);
38 mt_rand_real(mt_state *t)
40 return mrb_random_genrand_real1(t);
44 mrb_random_mt_srand(mrb_state *mrb, mt_state *t, mrb_value seed)
46 if (mrb_nil_p(seed)) {
47 seed = mrb_fixnum_value((mrb_int)(time(NULL) + mt_rand(t)));
48 if (mrb_fixnum(seed) < 0) {
49 seed = mrb_fixnum_value(0 - mrb_fixnum(seed));
53 mt_srand(t, (unsigned) mrb_fixnum(seed));
59 mrb_random_mt_rand(mrb_state *mrb, mt_state *t, mrb_value max)
63 if (mrb_fixnum(max) == 0) {
64 value = mrb_float_value(mrb, mt_rand_real(t));
67 value = mrb_fixnum_value(mt_rand(t) % mrb_fixnum(max));
74 get_opt(mrb_state* mrb)
78 arg = mrb_nil_value();
79 mrb_get_args(mrb, "|o", &arg);
81 if (!mrb_nil_p(arg)) {
84 arg = mrb_to_int(mrb, arg);
87 arg = mrb_fixnum_value(0 - i);
94 get_random(mrb_state *mrb) {
95 return mrb_const_get(mrb,
96 mrb_obj_value(mrb_class_get(mrb, "Random")),
97 mrb_intern_lit(mrb, "DEFAULT"));
101 get_random_state(mrb_state *mrb)
103 mrb_value random_val = get_random(mrb);
104 return DATA_GET_PTR(mrb, random_val, &mt_state_type, mt_state);
108 mrb_random_g_rand(mrb_state *mrb, mrb_value self)
110 mrb_value random = get_random(mrb);
111 return mrb_random_rand(mrb, random);
115 mrb_random_g_srand(mrb_state *mrb, mrb_value self)
117 mrb_value random = get_random(mrb);
118 return mrb_random_srand(mrb, random);
122 mrb_random_init(mrb_state *mrb, mrb_value self)
129 /* avoid memory leaks */
130 t = (mt_state*)DATA_PTR(self);
134 mrb_data_init(self, NULL, &mt_state_type);
136 t = (mt_state *)mrb_malloc(mrb, sizeof(mt_state));
139 seed = mrb_random_mt_srand(mrb, t, seed);
140 if (mrb_nil_p(seed)) {
144 mrb_assert(mrb_fixnum_p(seed));
146 t->seed = mrb_fixnum(seed);
149 mrb_data_init(self, t, &mt_state_type);
155 mrb_random_rand_seed(mrb_state *mrb, mt_state *t)
158 mrb_random_mt_srand(mrb, t, mrb_nil_value());
163 mrb_random_rand(mrb_state *mrb, mrb_value self)
166 mt_state *t = DATA_GET_PTR(mrb, self, &mt_state_type, mt_state);
169 mrb_random_rand_seed(mrb, t);
170 return mrb_random_mt_rand(mrb, t, max);
174 mrb_random_srand(mrb_state *mrb, mrb_value self)
178 mt_state *t = DATA_GET_PTR(mrb, self, &mt_state_type, mt_state);
181 seed = mrb_random_mt_srand(mrb, t, seed);
182 old_seed = t->has_seed? mrb_fixnum_value(t->seed) : mrb_nil_value();
183 if (mrb_nil_p(seed)) {
187 mrb_assert(mrb_fixnum_p(seed));
189 t->seed = mrb_fixnum(seed);
197 * ary.shuffle! -> ary
199 * Shuffles elements in self in place.
203 mrb_ary_shuffle_bang(mrb_state *mrb, mrb_value ary)
206 mt_state *random = NULL;
208 if (RARRAY_LEN(ary) > 1) {
209 mrb_get_args(mrb, "|d", &random, &mt_state_type);
211 if (random == NULL) {
212 random = get_random_state(mrb);
214 mrb_random_rand_seed(mrb, random);
216 mrb_ary_modify(mrb, mrb_ary_ptr(ary));
218 for (i = RARRAY_LEN(ary) - 1; i > 0; i--) {
220 mrb_value *ptr = RARRAY_PTR(ary);
224 j = mrb_fixnum(mrb_random_mt_rand(mrb, random, mrb_fixnum_value(RARRAY_LEN(ary))));
237 * ary.shuffle -> new_ary
239 * Returns a new array with elements of self shuffled.
243 mrb_ary_shuffle(mrb_state *mrb, mrb_value ary)
245 mrb_value new_ary = mrb_ary_new_from_values(mrb, RARRAY_LEN(ary), RARRAY_PTR(ary));
246 mrb_ary_shuffle_bang(mrb, new_ary);
254 * ary.sample(n) -> new_ary
256 * Choose a random element or +n+ random elements from the array.
258 * The elements are chosen by using random and unique indices into the array
259 * in order to ensure that an element doesn't repeat itself unless the array
260 * already contained duplicate elements.
262 * If the array is empty the first form returns +nil+ and the second form
263 * returns an empty array.
267 mrb_ary_sample(mrb_state *mrb, mrb_value ary)
271 mt_state *random = NULL;
274 mrb_get_args(mrb, "|i?d", &n, &given, &random, &mt_state_type);
275 if (random == NULL) {
276 random = get_random_state(mrb);
278 mrb_random_rand_seed(mrb, random);
280 len = RARRAY_LEN(ary);
281 if (!given) { /* pick one element */
284 return mrb_nil_value();
286 return RARRAY_PTR(ary)[0];
288 return RARRAY_PTR(ary)[mt_rand(random) % len];
295 if (n < 0) mrb_raise(mrb, E_ARGUMENT_ERROR, "negative sample number");
296 if (n > len) n = len;
297 result = mrb_ary_new_capa(mrb, n);
298 for (i=0; i<n; i++) {
303 r = mt_rand(random) % len;
305 for (j=0; j<i; j++) {
306 if (mrb_fixnum(RARRAY_PTR(result)[j]) == r) {
307 goto retry; /* retry if duplicate */
312 mrb_ary_push(mrb, result, mrb_fixnum_value(r));
314 for (i=0; i<n; i++) {
315 mrb_ary_set(mrb, result, i, RARRAY_PTR(ary)[mrb_fixnum(RARRAY_PTR(result)[i])]);
322 void mrb_mruby_random_gem_init(mrb_state *mrb)
324 struct RClass *random;
325 struct RClass *array = mrb->array_class;
327 mrb_define_method(mrb, mrb->kernel_module, "rand", mrb_random_g_rand, MRB_ARGS_OPT(1));
328 mrb_define_method(mrb, mrb->kernel_module, "srand", mrb_random_g_srand, MRB_ARGS_OPT(1));
330 random = mrb_define_class(mrb, "Random", mrb->object_class);
331 MRB_SET_INSTANCE_TT(random, MRB_TT_DATA);
332 mrb_define_class_method(mrb, random, "rand", mrb_random_g_rand, MRB_ARGS_OPT(1));
333 mrb_define_class_method(mrb, random, "srand", mrb_random_g_srand, MRB_ARGS_OPT(1));
335 mrb_define_method(mrb, random, "initialize", mrb_random_init, MRB_ARGS_OPT(1));
336 mrb_define_method(mrb, random, "rand", mrb_random_rand, MRB_ARGS_OPT(1));
337 mrb_define_method(mrb, random, "srand", mrb_random_srand, MRB_ARGS_OPT(1));
339 mrb_define_method(mrb, array, "shuffle", mrb_ary_shuffle, MRB_ARGS_OPT(1));
340 mrb_define_method(mrb, array, "shuffle!", mrb_ary_shuffle_bang, MRB_ARGS_OPT(1));
341 mrb_define_method(mrb, array, "sample", mrb_ary_sample, MRB_ARGS_OPT(2));
343 mrb_const_set(mrb, mrb_obj_value(random), mrb_intern_lit(mrb, "DEFAULT"),
344 mrb_obj_new(mrb, random, 0, NULL));
347 void mrb_mruby_random_gem_final(mrb_state *mrb)