[iter] Add hb_range()

hb_range() is like Python range.  hb_iota() has slightly different API.
Ie. it takes a start, instead of end.
This commit is contained in:
Behdad Esfahbod 2019-05-09 11:02:56 -07:00
parent 05867d9f53
commit 7675d0d3a6
2 changed files with 31 additions and 21 deletions

View File

@ -572,13 +572,13 @@ struct
}
HB_FUNCOBJ (hb_apply);
/* hb_iota() */
/* hb_iota()/hb_range() */
template <typename T, typename S>
struct hb_iota_iter_t :
hb_iter_t<hb_iota_iter_t<T, S>, T>
struct hb_counter_iter_t :
hb_iter_t<hb_counter_iter_t<T, S>, T>
{
hb_iota_iter_t (T start, T end_, S step) : v (start), end_ (end__for (start, end_, step)), step (step) {}
hb_counter_iter_t (T start, T end_, S step) : v (start), end_ (end__for (start, end_, step)), step (step) {}
typedef T __item_t__;
static constexpr bool is_random_access_iterator = true;
@ -591,8 +591,8 @@ struct hb_iota_iter_t :
void __forward__ (unsigned n) { v += n * step; }
void __prev__ () { v -= step; }
void __rewind__ (unsigned n) { v -= n * step; }
hb_iota_iter_t __end___ () const { hb_iota_iter_t (end_, end_, step); }
bool operator != (const hb_iota_iter_t& o) const
hb_counter_iter_t __end___ () const { hb_counter_iter_t (end_, end_, step); }
bool operator != (const hb_counter_iter_t& o) const
{ return v != o.v || end_ != o.end_ || step != o.step; }
private:
@ -612,15 +612,22 @@ struct hb_iota_iter_t :
};
struct
{
template <typename T = unsigned> hb_iota_iter_t<T, unsigned>
operator () (T end = (unsigned) -1) const
{ return hb_iota_iter_t<T, unsigned> (0, end, 1u); }
template <typename T, typename S = unsigned> hb_iota_iter_t<T, S>
operator () (T start, T end, S&& step = 1u) const
{ return hb_iota_iter_t<T, S> (start, end, step); }
template <typename T = unsigned, typename S = unsigned> hb_counter_iter_t<T, S>
operator () (T start = 0u, S&& step = 1u) const
{ return hb_counter_iter_t<T, S> (start, hb_int_max (T), step); }
}
HB_FUNCOBJ (hb_iota);
struct
{
template <typename T = unsigned> hb_counter_iter_t<T, unsigned>
operator () (T end = (unsigned) -1) const
{ return hb_counter_iter_t<T, unsigned> (0, end, 1u); }
template <typename T, typename S = unsigned> hb_counter_iter_t<T, S>
operator () (T start, T end, S&& step = 1u) const
{ return hb_counter_iter_t<T, S> (start, end, step); }
}
HB_FUNCOBJ (hb_range);
/* hb_sink() */

View File

@ -264,14 +264,17 @@ main (int argc, char **argv)
s >> vl;
hb_iota ();
assert (hb_iota (9).len () == 9);
assert (hb_iota (2, 9).len () == 7);
assert (hb_iota (2, 9, 3).len () == 3);
assert (hb_iota (2, 8, 3).len () == 2);
assert (hb_iota (2, 7, 3).len () == 2);
assert (hb_iota (-2, -9, -3).len () == 3);
assert (hb_iota (-2, -8, -3).len () == 2);
assert (hb_iota (-2, -7, -3).len () == 2);
hb_iota (3);
hb_iota (3, 2);
hb_range ();
assert (hb_range (9).len () == 9);
assert (hb_range (2, 9).len () == 7);
assert (hb_range (2, 9, 3).len () == 3);
assert (hb_range (2, 8, 3).len () == 2);
assert (hb_range (2, 7, 3).len () == 2);
assert (hb_range (-2, -9, -3).len () == 3);
assert (hb_range (-2, -8, -3).len () == 2);
assert (hb_range (-2, -7, -3).len () == 2);
return 0;
}