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array.c: combinate0

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* array.c (combinate0): extract.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46425 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
This commit is contained in:
nobu 2014-06-14 01:54:33 +00:00
parent 9729275473
commit 02725fb682
1 changed files with 23 additions and 17 deletions
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40
array.c
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@ -4884,6 +4884,27 @@ rb_ary_permutation(int argc, VALUE *argv, VALUE ary)
return ary;
}
static void
combinate0(const long len, const long n, long *const stack, const VALUE values)
{
long lev = 0;
MEMZERO(stack+1, long, n);
stack[0] = -1;
for (;;) {
for (lev++; lev < n; lev++) {
stack[lev+1] = stack[lev]+1;
}
if (!yield_indexed_values(values, n, stack+1)) {
rb_raise(rb_eRuntimeError, "combination reentered");
}
do {
if (lev == 0) return;
stack[lev--]++;
} while (stack[lev+1]+n == len+lev+1);
}
}
static VALUE
rb_ary_combination_size(VALUE ary, VALUE args, VALUE eobj)
{
@ -4921,7 +4942,7 @@ rb_ary_combination_size(VALUE ary, VALUE args, VALUE eobj)
static VALUE
rb_ary_combination(VALUE ary, VALUE num)
{
long n, i, len;
long i, n, len;
n = NUM2LONG(num);
RETURN_SIZED_ENUMERATOR(ary, 1, &num, rb_ary_combination_size);
@ -4941,24 +4962,9 @@ rb_ary_combination(VALUE ary, VALUE num)
VALUE ary0 = ary_make_shared_copy(ary); /* private defensive copy of ary */
volatile VALUE t0;
long *stack = ALLOCV_N(long, t0, n+1);
long lev = 0;
RBASIC_CLEAR_CLASS(ary0);
MEMZERO(stack+1, long, n);
stack[0] = -1;
for (;;) {
for (lev++; lev < n; lev++) {
stack[lev+1] = stack[lev]+1;
}
if (!yield_indexed_values(ary0, n, stack+1)) {
rb_raise(rb_eRuntimeError, "combination reentered");
}
do {
if (lev == 0) goto done;
stack[lev--]++;
} while (stack[lev+1]+n == len+lev+1);
}
done:
combinate0(len, n, stack, ary0);
ALLOCV_END(t0);
RBASIC_SET_CLASS_RAW(ary0, rb_cArray);
}