harfbuzz/src/hb-bit-set-invertible.hh

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/*
* Copyright © 2012,2017 Google, Inc.
* Copyright © 2021 Behdad Esfahbod
*
* This is part of HarfBuzz, a text shaping library.
*
* Permission is hereby granted, without written agreement and without
* license or royalty fees, to use, copy, modify, and distribute this
* software and its documentation for any purpose, provided that the
* above copyright notice and the following two paragraphs appear in
* all copies of this software.
*
* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*
* Google Author(s): Behdad Esfahbod
*/
#ifndef HB_BIT_SET_INVERTIBLE_HH
#define HB_BIT_SET_INVERTIBLE_HH
#include "hb.hh"
#include "hb-bit-set.hh"
struct hb_bit_set_invertible_t
{
hb_bit_set_t s;
bool inverted;
hb_bit_set_invertible_t () { init (); }
~hb_bit_set_invertible_t () { fini (); }
void init () { s.init (); inverted = false; }
void fini () { s.fini (); }
void err () { s.err (); }
bool in_error () const { return s.in_error (); }
explicit operator bool () const { return !is_empty (); }
void reset () { s.reset (); inverted = false; }
void clear () { s.clear (); inverted = false; }
void invert () { if (!s.in_error ()) inverted = !inverted; }
bool is_empty () const { return inverted ? /*XXX*/false : s.is_empty (); }
void add (hb_codepoint_t g) { unlikely (inverted) ? s.del (g) : s.add (g); }
bool add_range (hb_codepoint_t a, hb_codepoint_t b)
{ return unlikely (inverted) ? (s.del_range (a, b), true) : s.add_range (a, b); }
template <typename T>
void add_array (const T *array, unsigned int count, unsigned int stride=sizeof(T))
{ inverted ? s.del_array (array, count, stride) : s.add_array (array, count, stride); }
template <typename T>
void add_array (const hb_array_t<const T>& arr) { add_array (&arr, arr.len ()); }
/* Might return false if array looks unsorted.
* Used for faster rejection of corrupt data. */
template <typename T>
bool add_sorted_array (const T *array, unsigned int count, unsigned int stride=sizeof(T))
{ return inverted ? s.del_sorted_array (array, count, stride) : s.add_sorted_array (array, count, stride); }
template <typename T>
bool add_sorted_array (const hb_sorted_array_t<const T>& arr) { return add_sorted_array (&arr, arr.len ()); }
void del (hb_codepoint_t g) { unlikely (inverted) ? s.add (g) : s.del (g); }
void del_range (hb_codepoint_t a, hb_codepoint_t b)
{ unlikely (inverted) ? (void) s.add_range (a, b) : s.del_range (a, b); }
bool get (hb_codepoint_t g) const { return s.get (g) ^ inverted; }
/* Has interface. */
static constexpr bool SENTINEL = false;
typedef bool value_t;
value_t operator [] (hb_codepoint_t k) const { return get (k); }
bool has (hb_codepoint_t k) const { return (*this)[k] != SENTINEL; }
/* Predicate. */
bool operator () (hb_codepoint_t k) const { return has (k); }
/* Sink interface. */
hb_bit_set_invertible_t& operator << (hb_codepoint_t v)
{ add (v); return *this; }
hb_bit_set_invertible_t& operator << (const hb_pair_t<hb_codepoint_t, hb_codepoint_t>& range)
{ add_range (range.first, range.second); return *this; }
bool intersects (hb_codepoint_t first, hb_codepoint_t last) const
{
hb_codepoint_t c = first - 1;
return next (&c) && c <= last;
}
void set (const hb_bit_set_invertible_t &other) { s.set (other.s); inverted = other.inverted; }
bool is_equal (const hb_bit_set_invertible_t &other) const
{ return inverted == other.inverted /*XXX*/ && s.is_equal (other.s); }
bool is_subset (const hb_bit_set_invertible_t &larger_set) const
{
if (unlikely (inverted && !larger_set.inverted)) return false; /*XXX*/
if (unlikely (!inverted && larger_set.inverted))
return hb_all (hb_iter (s) | hb_map (larger_set.s));
/* inverted == larger_set.inverted */
return unlikely (inverted) ? larger_set.s.is_subset (s) : s.is_subset (larger_set.s);
}
protected:
template <typename Op>
void process (const Op& op, const hb_bit_set_invertible_t &other)
{ s.process (op, other.s); }
public:
void union_ (const hb_bit_set_invertible_t &other)
{
if (likely (inverted == other.inverted))
{
if (unlikely (inverted))
process (hb_bitwise_and, other);
else
process (hb_bitwise_or, other); /* Main branch. */
}
else
{
if (unlikely (inverted))
process (hb_bitwise_gt, other);
else
process (hb_bitwise_lt, other);
}
inverted = inverted || other.inverted;
}
void intersect (const hb_bit_set_invertible_t &other)
{
if (likely (inverted == other.inverted))
{
if (unlikely (inverted))
process (hb_bitwise_or, other);
else
process (hb_bitwise_and, other); /* Main branch. */
}
else
{
if (unlikely (inverted))
process (hb_bitwise_lt, other);
else
process (hb_bitwise_gt, other);
}
inverted = inverted && other.inverted;
}
void subtract (const hb_bit_set_invertible_t &other)
{
if (likely (inverted == other.inverted))
{
if (unlikely (inverted))
process (hb_bitwise_lt, other);
else
process (hb_bitwise_gt, other); /* Main branch. */
}
else
{
if (unlikely (inverted))
process (hb_bitwise_non, other);
else
process (hb_bitwise_and, other);
}
inverted = inverted && !other.inverted;
}
void symmetric_difference (const hb_bit_set_invertible_t &other)
{
process (hb_bitwise_xor, other);
inverted = inverted ^ other.inverted;
}
bool next (hb_codepoint_t *codepoint) const
{
if (likely (!inverted))
return s.next (codepoint);
auto old = *codepoint;
auto v = old;
s.next (&v);
if (old + 1 < v)
{
*codepoint = old + 1;
return true;
}
if (unlikely (old + 1 == INVALID))
{
*codepoint = INVALID;
return false;
}
s.next_range (&old, &v);
*codepoint = v + 1;
return *codepoint != INVALID;
}
bool previous (hb_codepoint_t *codepoint) const
{
if (likely (!inverted))
return s.previous (codepoint);
auto old = *codepoint;
auto v = old;
s.previous (&v);
if (old - 1 > v)
{
*codepoint = old - 1;
return true;
}
if (unlikely (old - 1 == INVALID))
{
*codepoint = INVALID;
return false;
}
s.previous_range (&v, &old);
*codepoint = v - 1;
return *codepoint != INVALID;
}
bool next_range (hb_codepoint_t *first, hb_codepoint_t *last) const
{
if (likely (!inverted))
return s.next_range (first, last);
if (!next (last))
{
*last = *first = INVALID;
return false;
}
*first = *last;
s.next (last);
--*last;
return true;
}
bool previous_range (hb_codepoint_t *first, hb_codepoint_t *last) const
{
if (likely (!inverted))
return s.previous_range (first, last);
if (!previous (first))
{
*last = *first = INVALID;
return false;
}
*last = *first;
s.previous (first);
++*first;
return true;
}
unsigned int get_population () const
{ return inverted ? INVALID - s.get_population () : s.get_population (); }
hb_codepoint_t get_min () const
{ return s.get_min (inverted); }
hb_codepoint_t get_max () const
{ return unlikely (inverted) ? /*XXX*/ INVALID - 1 : s.get_max (); }
static constexpr hb_codepoint_t INVALID = hb_bit_set_t::INVALID;
/*
* Iterator implementation.
*/
struct iter_t : hb_iter_with_fallback_t<iter_t, hb_codepoint_t>
{
static constexpr bool is_sorted_iterator = true;
iter_t (const hb_bit_set_invertible_t &s_ = Null (hb_bit_set_invertible_t),
bool init = true) : s (&s_), v (INVALID), l(0)
{
if (init)
{
l = s->get_population () + 1;
__next__ ();
}
}
typedef hb_codepoint_t __item_t__;
hb_codepoint_t __item__ () const { return v; }
bool __more__ () const { return v != INVALID; }
void __next__ () { s->next (&v); if (l) l--; }
void __prev__ () { s->previous (&v); }
unsigned __len__ () const { return l; }
iter_t end () const { return iter_t (*s, false); }
bool operator != (const iter_t& o) const
{ return s != o.s || v != o.v; }
protected:
const hb_bit_set_invertible_t *s;
hb_codepoint_t v;
unsigned l;
};
iter_t iter () const { return iter_t (*this); }
operator iter_t () const { return iter (); }
};
#endif /* HB_BIT_SET_INVERTIBLE_HH */