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Feature #5584 » by_sorah.diff

sorah (Sorah Fukumori), 11/08/2011 11:37 PM

View differences:

array.c
return ary;
}
/*
* call-seq:
* ary.sample -> obj
* ary.sample(random: rng) -> obj
* ary.sample(n) -> new_ary
* ary.sample(n, random: rng) -> new_ary
*
* Choose a random element or +n+ random elements from the array. The elements
* are chosen by using random and unique indices into the array in order to
* ensure that an element doesn't repeat itself unless the array already
* contained duplicate elements. If the array is empty the first form returns
* <code>nil</code> and the second form returns an empty array.
*
* If +rng+ is given, it will be used as the random number generator.
*/
static VALUE
rb_ary_sample(int argc, VALUE *argv, VALUE ary)
ary_sample(int argc, VALUE *argv, VALUE ary, int removing)
{
VALUE nv, result, *ptr;
VALUE opts, randgen = rb_cRandom;
VALUE *ptr_result;
long n, len, i, j, k, idx[10];
double rnds[numberof(idx)];
......
if ((len = RARRAY_LEN(ary)) == 0) return Qnil;
i = (long)(x * len);
}
return RARRAY_PTR(ary)[i];
return (removing ? rb_ary_delete_at(ary, i) : RARRAY_PTR(ary)[i]);
}
rb_scan_args(argc, argv, "1", &nv);
n = NUM2LONG(nv);
......
return rb_ary_new2(0);
case 1:
i = (long)(rnds[0] * len);
return rb_ary_new4(1, &ptr[i]);
return (removing ? rb_ary_new3(1, rb_ary_delete_at(ary, i)) : rb_ary_new4(1, &ptr[i]));
case 2:
i = (long)(rnds[0] * len);
j = (long)(rnds[1] * (len-1));
if (j >= i) j++;
return rb_ary_new3(2, ptr[i], ptr[j]);
result = rb_ary_new3(2, ptr[i], ptr[j]);
if (removing) {
rb_ary_delete_at(ary, i);
if (i < j) j--;
rb_ary_delete_at(ary, j);
}
return result;
case 3:
i = (long)(rnds[0] * len);
j = (long)(rnds[1] * (len-1));
......
if (j >= i) l = i, g = ++j;
if (k >= l && (++k >= g)) ++k;
}
return rb_ary_new3(3, ptr[i], ptr[j], ptr[k]);
result = rb_ary_new3(3, ptr[i], ptr[j], ptr[k]);
if (removing) {
long l, g;
if (i < k) l = i, g = k, i = g, k = l;
if (i < j) l = i, g = j, i = g, j = l;
rb_ary_delete_at(ary, i);
rb_ary_delete_at(ary, j);
rb_ary_delete_at(ary, k);
}
return result;
}
if (n <= numberof(idx)) {
VALUE *ptr_result;
if (removing) {
result = rb_ary_new2(n);
ptr_result = RARRAY_PTR(result);
for (i=0; i<n; i++) {
j = (long)(rb_random_real(randgen) * --len);
ptr_result[i] = rb_ary_delete_at(ary, j);
}
}
else if (n <= numberof(idx)) {
long sorted[numberof(idx)];
sorted[0] = idx[0] = (long)(rnds[0] * len);
for (i=1; i<n; i++) {
......
}
}
else {
VALUE *ptr_result;
result = rb_ary_new4(len, ptr);
RBASIC(result)->klass = 0;
ptr_result = RARRAY_PTR(result);
......
return result;
}
/*
* call-seq:
* ary.sample -> obj
* ary.sample(random: rng) -> obj
* ary.sample(n) -> new_ary
* ary.sample(n, random: rng) -> new_ary
*
* Choose a random element or +n+ random elements from the array. The elements
* are chosen by using random and unique indices into the array in order to
* ensure that an element doesn't repeat itself unless the array already
* contained duplicate elements. If the array is empty the first form returns
* <code>nil</code> and the second form returns an empty array.
*
* If +rng+ is given, it will be used as the random number generator.
*/
static VALUE
rb_ary_sample(int argc, VALUE *argv, VALUE ary)
{
return ary_sample(argc, argv, ary, 0);
}
/*
* call-seq:
* ary.sample! -> obj
* ary.sample!(random: rng) -> obj
* ary.sample!(n) -> new_ary
* ary.sample!(n, random: rng) -> new_ary
*
* Choose and remove a random element or +n+ random elements from the array.
* The elements are chosen by using random and unique indices into the array in
* order to ensure that an element doesn't repeat itself unless the array
* already contained duplicate elements. If the array is empty the first form
* returns <code>nil</code> and the second form returns an empty array.
*
* If +rng+ is given, it will be used as the random number generator.
*/
static VALUE
rb_ary_sample_bang(int argc, VALUE *argv, VALUE ary)
{
return ary_sample(argc, argv, ary, 1);
}
/*
* call-seq:
......
rb_define_method(rb_cArray, "shuffle!", rb_ary_shuffle_bang, -1);
rb_define_method(rb_cArray, "shuffle", rb_ary_shuffle, -1);
rb_define_method(rb_cArray, "sample", rb_ary_sample, -1);
rb_define_method(rb_cArray, "sample!", rb_ary_sample_bang, -1);
rb_define_method(rb_cArray, "cycle", rb_ary_cycle, -1);
rb_define_method(rb_cArray, "permutation", rb_ary_permutation, -1);
rb_define_method(rb_cArray, "combination", rb_ary_combination, 1);
(2-2/2)