[set] Add backwards iterator

New API:
- hb_set_previous()
- hb_set_previous_range()
This commit is contained in:
Behdad Esfahbod 2018-02-14 01:00:10 -08:00
parent fe3bc524bd
commit 694eaf6367
5 changed files with 194 additions and 8 deletions

View File

@ -528,7 +528,9 @@ hb_set_intersect
hb_set_is_empty hb_set_is_empty
hb_set_is_equal hb_set_is_equal
hb_set_next hb_set_next
hb_set_previous
hb_set_next_range hb_set_next_range
hb_set_previous_range
hb_set_reference hb_set_reference
hb_set_set hb_set_set
hb_set_set_user_data hb_set_set_user_data

View File

@ -121,6 +121,33 @@ struct hb_set_t
*codepoint = INVALID; *codepoint = INVALID;
return false; return false;
found:
*codepoint = i * ELT_BITS + j;
return true;
}
inline bool previous (hb_codepoint_t *codepoint) const
{
unsigned int m = (*codepoint - 1) & MASK;
if (m == MASK)
{
*codepoint = INVALID;
return false;
}
unsigned int i = m / ELT_BITS;
unsigned int j = m & ELT_MASK;
for (; (int) j >= 0; j--)
if (v[i] & (elt_t (1) << j))
goto found;
for (i--; (int) i >= 0; i--)
if (v[i])
for (j = ELT_BITS - 1; (int) j >= 0; j--)
if (v[i] & (elt_t (1) << j))
goto found;
*codepoint = INVALID;
return false;
found: found:
*codepoint = i * ELT_BITS + j; *codepoint = i * ELT_BITS + j;
return true; return true;
@ -476,7 +503,7 @@ struct hb_set_t
if (pages[page_map[i].index].next (codepoint)) if (pages[page_map[i].index].next (codepoint))
{ {
*codepoint += page_map[i].major * page_t::PAGE_BITS; *codepoint += page_map[i].major * page_t::PAGE_BITS;
return true; return true;
} }
i++; i++;
} }
@ -492,6 +519,37 @@ struct hb_set_t
*codepoint = INVALID; *codepoint = INVALID;
return false; return false;
} }
inline bool previous (hb_codepoint_t *codepoint) const
{
if (unlikely (*codepoint == INVALID)) {
*codepoint = get_max ();
return *codepoint != INVALID;
}
page_map_t map = {get_major (*codepoint), 0};
unsigned int i;
page_map.bfind (map, &i);
if (i < page_map.len && page_map[i].major == map.major)
{
if (pages[page_map[i].index].previous (codepoint))
{
*codepoint += page_map[i].major * page_t::PAGE_BITS;
return true;
}
}
i--;
for (; (int) i >= 0; i--)
{
hb_codepoint_t m = pages[page_map[i].index].get_max ();
if (m != INVALID)
{
*codepoint = page_map[i].major * page_t::PAGE_BITS + m;
return true;
}
}
*codepoint = INVALID;
return false;
}
inline bool next_range (hb_codepoint_t *first, hb_codepoint_t *last) const inline bool next_range (hb_codepoint_t *first, hb_codepoint_t *last) const
{ {
hb_codepoint_t i; hb_codepoint_t i;
@ -503,12 +561,31 @@ struct hb_set_t
return false; return false;
} }
/* TODO Speed up. */
*last = *first = i; *last = *first = i;
while (next (&i) && i == *last + 1) while (next (&i) && i == *last + 1)
(*last)++; (*last)++;
return true; return true;
} }
inline bool previous_range (hb_codepoint_t *first, hb_codepoint_t *last) const
{
hb_codepoint_t i;
i = *first;
if (!previous (&i))
{
*last = *first = INVALID;
return false;
}
/* TODO Speed up. */
*last = *first = i;
while (previous (&i) && i == *first - 1)
(*first)--;
return true;
}
inline unsigned int get_population (void) const inline unsigned int get_population (void) const
{ {

View File

@ -437,7 +437,9 @@ hb_set_get_max (const hb_set_t *set)
* @set: a set. * @set: a set.
* @codepoint: (inout): * @codepoint: (inout):
* *
* * Gets the next number in @set that is greater than current value of @codepoint.
*
* Set @codepoint to %HB_SET_VALUE_INVALID to get started.
* *
* Return value: whether there was a next value. * Return value: whether there was a next value.
* *
@ -450,6 +452,26 @@ hb_set_next (const hb_set_t *set,
return set->next (codepoint); return set->next (codepoint);
} }
/**
* hb_set_previous:
* @set: a set.
* @codepoint: (inout):
*
* Gets the previous number in @set that is slower than current value of @codepoint.
*
* Set @codepoint to %HB_SET_VALUE_INVALID to get started.
*
* Return value: whether there was a previous value.
*
* Since: 1.8.0
**/
hb_bool_t
hb_set_previous (const hb_set_t *set,
hb_codepoint_t *codepoint)
{
return set->previous (codepoint);
}
/** /**
* hb_set_next_range: * hb_set_next_range:
* @set: a set. * @set: a set.
@ -459,6 +481,8 @@ hb_set_next (const hb_set_t *set,
* Gets the next consecutive range of numbers in @set that * Gets the next consecutive range of numbers in @set that
* are greater than current value of @last. * are greater than current value of @last.
* *
* Set @last to %HB_SET_VALUE_INVALID to get started.
*
* Return value: whether there was a next range. * Return value: whether there was a next range.
* *
* Since: 0.9.7 * Since: 0.9.7
@ -470,3 +494,26 @@ hb_set_next_range (const hb_set_t *set,
{ {
return set->next_range (first, last); return set->next_range (first, last);
} }
/**
* hb_set_previous_range:
* @set: a set.
* @first: (inout): input current first and output first codepoint in the range.
* @last: (out): output last codepoint in the range.
*
* Gets the previous consecutive range of numbers in @set that
* are greater than current value of @last.
*
* Set @first to %HB_SET_VALUE_INVALID to get started.
*
* Return value: whether there was a previous range.
*
* Since: 1.8.0
**/
hb_bool_t
hb_set_previous_range (const hb_set_t *set,
hb_codepoint_t *first,
hb_codepoint_t *last)
{
return set->previous_range (first, last);
}

View File

@ -129,25 +129,36 @@ hb_set_symmetric_difference (hb_set_t *set,
HB_EXTERN unsigned int HB_EXTERN unsigned int
hb_set_get_population (const hb_set_t *set); hb_set_get_population (const hb_set_t *set);
/* Returns -1 if set empty. */ /* Returns HB_SET_VALUE_INVALID if set empty. */
HB_EXTERN hb_codepoint_t HB_EXTERN hb_codepoint_t
hb_set_get_min (const hb_set_t *set); hb_set_get_min (const hb_set_t *set);
/* Returns -1 if set empty. */ /* Returns HB_SET_VALUE_INVALID if set empty. */
HB_EXTERN hb_codepoint_t HB_EXTERN hb_codepoint_t
hb_set_get_max (const hb_set_t *set); hb_set_get_max (const hb_set_t *set);
/* Pass -1 in to get started. */ /* Pass HB_SET_VALUE_INVALID in to get started. */
HB_EXTERN hb_bool_t HB_EXTERN hb_bool_t
hb_set_next (const hb_set_t *set, hb_set_next (const hb_set_t *set,
hb_codepoint_t *codepoint); hb_codepoint_t *codepoint);
/* Pass -1 for first and last to get started. */ /* Pass HB_SET_VALUE_INVALID in to get started. */
HB_EXTERN hb_bool_t
hb_set_previous (const hb_set_t *set,
hb_codepoint_t *codepoint);
/* Pass HB_SET_VALUE_INVALID for first and last to get started. */
HB_EXTERN hb_bool_t HB_EXTERN hb_bool_t
hb_set_next_range (const hb_set_t *set, hb_set_next_range (const hb_set_t *set,
hb_codepoint_t *first, hb_codepoint_t *first,
hb_codepoint_t *last); hb_codepoint_t *last);
/* Pass HB_SET_VALUE_INVALID for first and last to get started. */
HB_EXTERN hb_bool_t
hb_set_previous_range (const hb_set_t *set,
hb_codepoint_t *first,
hb_codepoint_t *last);
HB_END_DECLS HB_END_DECLS

View File

@ -32,25 +32,33 @@
static void static void
test_empty (hb_set_t *s) test_empty (hb_set_t *s)
{ {
hb_codepoint_t next = HB_SET_VALUE_INVALID; hb_codepoint_t next;
g_assert_cmpint (hb_set_get_population (s), ==, 0); g_assert_cmpint (hb_set_get_population (s), ==, 0);
g_assert_cmpint (hb_set_get_min (s), ==, HB_SET_VALUE_INVALID); g_assert_cmpint (hb_set_get_min (s), ==, HB_SET_VALUE_INVALID);
g_assert_cmpint (hb_set_get_max (s), ==, HB_SET_VALUE_INVALID); g_assert_cmpint (hb_set_get_max (s), ==, HB_SET_VALUE_INVALID);
g_assert (!hb_set_has (s, 13)); g_assert (!hb_set_has (s, 13));
next = 53043;
g_assert (!hb_set_next (s, &next)); g_assert (!hb_set_next (s, &next));
g_assert_cmpint (next, ==, HB_SET_VALUE_INVALID); g_assert_cmpint (next, ==, HB_SET_VALUE_INVALID);
next = 07734;
g_assert (!hb_set_previous (s, &next));
g_assert_cmpint (next, ==, HB_SET_VALUE_INVALID);
g_assert (hb_set_is_empty (s)); g_assert (hb_set_is_empty (s));
} }
static void static void
test_not_empty (hb_set_t *s) test_not_empty (hb_set_t *s)
{ {
hb_codepoint_t next = HB_SET_VALUE_INVALID; hb_codepoint_t next;
g_assert_cmpint (hb_set_get_population (s), !=, 0); g_assert_cmpint (hb_set_get_population (s), !=, 0);
g_assert_cmpint (hb_set_get_min (s), !=, HB_SET_VALUE_INVALID); g_assert_cmpint (hb_set_get_min (s), !=, HB_SET_VALUE_INVALID);
g_assert_cmpint (hb_set_get_max (s), !=, HB_SET_VALUE_INVALID); g_assert_cmpint (hb_set_get_max (s), !=, HB_SET_VALUE_INVALID);
next = HB_SET_VALUE_INVALID;
g_assert (hb_set_next (s, &next)); g_assert (hb_set_next (s, &next));
g_assert_cmpint (next, !=, HB_SET_VALUE_INVALID); g_assert_cmpint (next, !=, HB_SET_VALUE_INVALID);
next = HB_SET_VALUE_INVALID;
g_assert (hb_set_previous (s, &next));
g_assert_cmpint (next, !=, HB_SET_VALUE_INVALID);
} }
static void static void
@ -271,6 +279,27 @@ test_set_iter (void)
g_assert (!hb_set_next (s, &next)); g_assert (!hb_set_next (s, &next));
g_assert_cmpint (next, ==, HB_SET_VALUE_INVALID); g_assert_cmpint (next, ==, HB_SET_VALUE_INVALID);
next = HB_SET_VALUE_INVALID;
g_assert (hb_set_previous (s, &next));
g_assert_cmpint (next, ==, 20005);
g_assert (hb_set_previous (s, &next));
g_assert_cmpint (next, ==, 1200);
g_assert (hb_set_previous (s, &next));
g_assert_cmpint (next, ==, 1100);
g_assert (hb_set_previous (s, &next));
g_assert_cmpint (next, ==, 15);
g_assert (hb_set_previous (s, &next));
g_assert (hb_set_previous (s, &next));
g_assert_cmpint (next, ==, 13);
g_assert (hb_set_previous (s, &next));
g_assert (hb_set_previous (s, &next));
g_assert (hb_set_previous (s, &next));
g_assert_cmpint (next, ==, 10);
g_assert (hb_set_previous (s, &next));
g_assert_cmpint (next, ==, 6);
g_assert (!hb_set_previous (s, &next));
g_assert_cmpint (next, ==, HB_SET_VALUE_INVALID);
first = last = HB_SET_VALUE_INVALID; first = last = HB_SET_VALUE_INVALID;
g_assert (hb_set_next_range (s, &first, &last)); g_assert (hb_set_next_range (s, &first, &last));
g_assert_cmpint (first, ==, 6); g_assert_cmpint (first, ==, 6);
@ -291,6 +320,26 @@ test_set_iter (void)
g_assert_cmpint (first, ==, HB_SET_VALUE_INVALID); g_assert_cmpint (first, ==, HB_SET_VALUE_INVALID);
g_assert_cmpint (last, ==, HB_SET_VALUE_INVALID); g_assert_cmpint (last, ==, HB_SET_VALUE_INVALID);
first = last = HB_SET_VALUE_INVALID;
g_assert (hb_set_previous_range (s, &first, &last));
g_assert_cmpint (first, ==, 20005);
g_assert_cmpint (last, ==, 20005);
g_assert (hb_set_previous_range (s, &first, &last));
g_assert_cmpint (first, ==, 1200);
g_assert_cmpint (last, ==, 1200);
g_assert (hb_set_previous_range (s, &first, &last));
g_assert_cmpint (first, ==, 1100);
g_assert_cmpint (last, ==, 1100);
g_assert (hb_set_previous_range (s, &first, &last));
g_assert_cmpint (first, ==, 10);
g_assert_cmpint (last, ==, 15);
g_assert (hb_set_previous_range (s, &first, &last));
g_assert_cmpint (first, ==, 6);
g_assert_cmpint (last, ==, 6);
g_assert (!hb_set_previous_range (s, &first, &last));
g_assert_cmpint (first, ==, HB_SET_VALUE_INVALID);
g_assert_cmpint (last, ==, HB_SET_VALUE_INVALID);
hb_set_destroy (s); hb_set_destroy (s);
} }