src/hb-ot-shaper-use-machine.rl - third_party/harfbuzz - Git at Google

 /*
  * Copyright © 2015  Mozilla Foundation.
  * Copyright © 2015  Google, Inc.
  *
  *  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.
  *
  * Mozilla Author(s): Jonathan Kew
  * Google Author(s): Behdad Esfahbod
  */

 #ifndef HB_OT_SHAPER_USE_MACHINE_HH
 #define HB_OT_SHAPER_USE_MACHINE_HH

 #include "hb.hh"

 #include "hb-ot-shaper-syllabic.hh"

 /* buffer var allocations */
 #define use_category() ot_shaper_var_u8_category()

 #define USE(Cat) use_syllable_machine_ex_##Cat

 enum use_syllable_type_t {
   use_virama_terminated_cluster,
   use_sakot_terminated_cluster,
   use_standard_cluster,
   use_number_joiner_terminated_cluster,
   use_numeral_cluster,
   use_symbol_cluster,
   use_hieroglyph_cluster,
   use_broken_cluster,
   use_non_cluster,
 };

 %%{
   machine use_syllable_machine;
   alphtype unsigned char;
   write exports;
   write data;
 }%%

 %%{

 # Categories used in the Universal Shaping Engine spec:
 # https://docs.microsoft.com/en-us/typography/script-development/use

 export O	= 0; # OTHER

 export B	= 1; # BASE
 export N	= 4; # BASE_NUM
 export GB	= 5; # BASE_OTHER
 export CGJ	= 6; # CGJ
 export SUB	= 11; # CONS_SUB
 export H	= 12; # HALANT

 export HN	= 13; # HALANT_NUM
 export ZWNJ	= 14; # Zero width non-joiner
 export WJ	= 16; # Word joiner
 export R	= 18; # REPHA
 export CS	= 43; # CONS_WITH_STACKER
 export IS	= 44; # INVISIBLE_STACKER
 export Sk	= 48; # SAKOT
 export G	= 49; # HIEROGLYPH
 export J	= 50; # HIEROGLYPH_JOINER
 export SB	= 51; # HIEROGLYPH_SEGMENT_BEGIN
 export SE	= 52; # HIEROGLYPH_SEGMENT_END
 export HVM	= 53; # HALANT_OR_VOWEL_MODIFIER
 export HM	= 54; # HIEROGLYPH_MOD
 export HR	= 55; # HIEROGLYPH_MIRROR

 export FAbv	= 24; # CONS_FINAL_ABOVE
 export FBlw	= 25; # CONS_FINAL_BELOW
 export FPst	= 26; # CONS_FINAL_POST
 export MAbv	= 27; # CONS_MED_ABOVE
 export MBlw	= 28; # CONS_MED_BELOW
 export MPst	= 29; # CONS_MED_POST
 export MPre	= 30; # CONS_MED_PRE
 export CMAbv	= 31; # CONS_MOD_ABOVE
 export CMBlw	= 32; # CONS_MOD_BELOW
 export VAbv	= 33; # VOWEL_ABOVE / VOWEL_ABOVE_BELOW / VOWEL_ABOVE_BELOW_POST / VOWEL_ABOVE_POST
 export VBlw	= 34; # VOWEL_BELOW / VOWEL_BELOW_POST
 export VPst	= 35; # VOWEL_POST	UIPC = Right
 export VPre	= 22; # VOWEL_PRE / VOWEL_PRE_ABOVE / VOWEL_PRE_ABOVE_POST / VOWEL_PRE_POST
 export VMAbv	= 37; # VOWEL_MOD_ABOVE
 export VMBlw	= 38; # VOWEL_MOD_BELOW
 export VMPst	= 39; # VOWEL_MOD_POST
 export VMPre	= 23; # VOWEL_MOD_PRE
 export SMAbv	= 41; # SYM_MOD_ABOVE
 export SMBlw	= 42; # SYM_MOD_BELOW
 export FMAbv	= 45; # CONS_FINAL_MOD	UIPC = Top
 export FMBlw	= 46; # CONS_FINAL_MOD	UIPC = Bottom
 export FMPst	= 47; # CONS_FINAL_MOD	UIPC = Not_Applicable


 h = H | HVM | IS | Sk;

 consonant_modifiers = CMAbv* CMBlw* ((h B | SUB) CMAbv* CMBlw*)*;
 medial_consonants = MPre? MAbv? MBlw? MPst?;
 dependent_vowels = VPre* VAbv* VBlw* VPst* | H;
 vowel_modifiers = HVM? VMPre* VMAbv* VMBlw* VMPst*;
 final_consonants = FAbv* FBlw* FPst*;
 final_modifiers = FMAbv* FMBlw* | FMPst?;

 complex_syllable_start = (R | CS)? (B | GB);
 complex_syllable_middle =
 	consonant_modifiers
 	medial_consonants
 	dependent_vowels
 	vowel_modifiers
 	(Sk B)*
 ;
 complex_syllable_tail =
 	complex_syllable_middle
 	final_consonants
 	final_modifiers
 ;
 number_joiner_terminated_cluster_tail = (HN N)* HN;
 numeral_cluster_tail = (HN N)+;
 symbol_cluster_tail = SMAbv+ SMBlw* | SMBlw+;

 virama_terminated_cluster_tail =
 	consonant_modifiers
 	IS
 ;
 virama_terminated_cluster =
 	complex_syllable_start
 	virama_terminated_cluster_tail
 ;
 sakot_terminated_cluster_tail =
 	complex_syllable_middle
 	Sk
 ;
 sakot_terminated_cluster =
 	complex_syllable_start
 	sakot_terminated_cluster_tail
 ;
 standard_cluster =
 	complex_syllable_start
 	complex_syllable_tail
 ;
 tail = complex_syllable_tail | sakot_terminated_cluster_tail | symbol_cluster_tail | virama_terminated_cluster_tail;
 broken_cluster =
 	R?
 	(tail | number_joiner_terminated_cluster_tail | numeral_cluster_tail)
 ;

 number_joiner_terminated_cluster = N number_joiner_terminated_cluster_tail;
 numeral_cluster = N numeral_cluster_tail?;
 symbol_cluster = (O | GB | SB) tail?;
 hieroglyph_cluster = SB* G HR? HM? SE* (J SB* (G HR? HM? SE*)?)*;
 other = any;

 main := |*
 	virama_terminated_cluster ZWNJ?		=> { found_syllable (use_virama_terminated_cluster); };
 	sakot_terminated_cluster ZWNJ?		=> { found_syllable (use_sakot_terminated_cluster); };
 	standard_cluster ZWNJ?			=> { found_syllable (use_standard_cluster); };
 	number_joiner_terminated_cluster ZWNJ?	=> { found_syllable (use_number_joiner_terminated_cluster); };
 	numeral_cluster ZWNJ?			=> { found_syllable (use_numeral_cluster); };
 	symbol_cluster ZWNJ?			=> { found_syllable (use_symbol_cluster); };
 	hieroglyph_cluster ZWNJ?		=> { found_syllable (use_hieroglyph_cluster); };
 	broken_cluster ZWNJ?			=> { found_syllable (use_broken_cluster); buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_BROKEN_SYLLABLE; };
 	other					=> { found_syllable (use_non_cluster); };
 *|;


 }%%

 #define found_syllable(syllable_type) \
   HB_STMT_START { \
     if (0) fprintf (stderr, "syllable %u..%u %s\n", (*ts).second.first, (*te).second.first, #syllable_type); \
     for (unsigned i = (*ts).second.first; i < (*te).second.first; ++i) \
       info[i].syllable() = (syllable_serial << 4) | syllable_type; \
     syllable_serial++; \
     if (syllable_serial == 16) syllable_serial = 1; \
   } HB_STMT_END


 template <typename Iter>
 struct machine_index_t :
   hb_iter_with_fallback_t<machine_index_t<Iter>,
 			  typename Iter::item_t>
 {
   machine_index_t (const Iter& it) : it (it) {}
   machine_index_t (const machine_index_t& o) : hb_iter_with_fallback_t<machine_index_t<Iter>,
 								       typename Iter::item_t> (),
 					       it (o.it), is_null (o.is_null) {}

   static constexpr bool is_random_access_iterator = Iter::is_random_access_iterator;
   static constexpr bool is_sorted_iterator = Iter::is_sorted_iterator;

   typename Iter::item_t __item__ () const { return *it; }
   typename Iter::item_t __item_at__ (unsigned i) const { return it[i]; }
   unsigned __len__ () const { return it.len (); }
   void __next__ () { ++it; }
   void __forward__ (unsigned n) { it += n; }
   void __prev__ () { --it; }
   void __rewind__ (unsigned n) { it -= n; }

   void operator = (unsigned n)
   {
     assert (n == 0);
     is_null = true;
   }
   explicit operator bool () { return !is_null; }

   void operator = (const machine_index_t& o)
   {
     is_null = o.is_null;
     unsigned index = (*it).first;
     unsigned n = (*o.it).first;
     if (index < n) it += n - index; else if (index > n) it -= index - n;
   }
   bool operator == (const machine_index_t& o) const
   { return is_null ? o.is_null : !o.is_null && (*it).first == (*o.it).first; }
   bool operator != (const machine_index_t& o) const { return !(*this == o); }

   private:
   Iter it;
   bool is_null = false;
 };
 struct
 {
   template <typename Iter,
 	    hb_requires (hb_is_iterable (Iter))>
   machine_index_t<hb_iter_type<Iter>>
   operator () (Iter&& it) const
   { return machine_index_t<hb_iter_type<Iter>> (hb_iter (it)); }
 }
 HB_FUNCOBJ (machine_index);


 static bool
 not_ccs_default_ignorable (const hb_glyph_info_t &i)
 { return i.use_category() != USE(CGJ); }

 static inline void
 find_syllables_use (hb_buffer_t *buffer)
 {
   hb_glyph_info_t *info = buffer->info;
   auto p =
     + hb_iter (info, buffer->len)
     | hb_enumerate
     | hb_filter ([] (const hb_glyph_info_t &i) { return not_ccs_default_ignorable (i); },
 		 hb_second)
     | hb_filter ([&] (const hb_pair_t<unsigned, const hb_glyph_info_t &> p)
 		 {
 		   if (p.second.use_category() == USE(ZWNJ))
 		     for (unsigned i = p.first + 1; i < buffer->len; ++i)
 		       if (not_ccs_default_ignorable (info[i]))
 			 return !_hb_glyph_info_is_unicode_mark (&info[i]);
 		   return true;
 		 })
     | hb_enumerate
     | machine_index
     ;
   auto pe = p + p.len ();
   auto eof = +pe;
   auto ts = +p;
   auto te = +p;
   unsigned int act HB_UNUSED;
   int cs;
   %%{
     write init;
     getkey (*p).second.second.use_category();
   }%%

   unsigned int syllable_serial = 1;
   %%{
     write exec;
   }%%
 }

 #undef found_syllable

 #endif /* HB_OT_SHAPER_USE_MACHINE_HH */
	/*
	* Copyright © 2015 Mozilla Foundation.
	* Copyright © 2015 Google, Inc.
	*
	* 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.
	*
	* Mozilla Author(s): Jonathan Kew
	* Google Author(s): Behdad Esfahbod
	*/

	#ifndef HB_OT_SHAPER_USE_MACHINE_HH
	#define HB_OT_SHAPER_USE_MACHINE_HH

	#include "hb.hh"

	#include "hb-ot-shaper-syllabic.hh"

	/* buffer var allocations */
	#define use_category() ot_shaper_var_u8_category()

	#define USE(Cat) use_syllable_machine_ex_##Cat

	enum use_syllable_type_t {
	use_virama_terminated_cluster,
	use_sakot_terminated_cluster,
	use_standard_cluster,
	use_number_joiner_terminated_cluster,
	use_numeral_cluster,
	use_symbol_cluster,
	use_hieroglyph_cluster,
	use_broken_cluster,
	use_non_cluster,
	};

	%%{
	machine use_syllable_machine;
	alphtype unsigned char;
	write exports;
	write data;
	}%%

	%%{

	# Categories used in the Universal Shaping Engine spec:
	# https://docs.microsoft.com/en-us/typography/script-development/use

	export O = 0; # OTHER

	export B = 1; # BASE
	export N = 4; # BASE_NUM
	export GB = 5; # BASE_OTHER
	export CGJ = 6; # CGJ
	export SUB = 11; # CONS_SUB
	export H = 12; # HALANT

	export HN = 13; # HALANT_NUM
	export ZWNJ = 14; # Zero width non-joiner
	export WJ = 16; # Word joiner
	export R = 18; # REPHA
	export CS = 43; # CONS_WITH_STACKER
	export IS = 44; # INVISIBLE_STACKER
	export Sk = 48; # SAKOT
	export G = 49; # HIEROGLYPH
	export J = 50; # HIEROGLYPH_JOINER
	export SB = 51; # HIEROGLYPH_SEGMENT_BEGIN
	export SE = 52; # HIEROGLYPH_SEGMENT_END
	export HVM = 53; # HALANT_OR_VOWEL_MODIFIER
	export HM = 54; # HIEROGLYPH_MOD
	export HR = 55; # HIEROGLYPH_MIRROR

	export FAbv = 24; # CONS_FINAL_ABOVE
	export FBlw = 25; # CONS_FINAL_BELOW
	export FPst = 26; # CONS_FINAL_POST
	export MAbv = 27; # CONS_MED_ABOVE
	export MBlw = 28; # CONS_MED_BELOW
	export MPst = 29; # CONS_MED_POST
	export MPre = 30; # CONS_MED_PRE
	export CMAbv = 31; # CONS_MOD_ABOVE
	export CMBlw = 32; # CONS_MOD_BELOW
	export VAbv = 33; # VOWEL_ABOVE / VOWEL_ABOVE_BELOW / VOWEL_ABOVE_BELOW_POST / VOWEL_ABOVE_POST
	export VBlw = 34; # VOWEL_BELOW / VOWEL_BELOW_POST
	export VPst = 35; # VOWEL_POST UIPC = Right
	export VPre = 22; # VOWEL_PRE / VOWEL_PRE_ABOVE / VOWEL_PRE_ABOVE_POST / VOWEL_PRE_POST
	export VMAbv = 37; # VOWEL_MOD_ABOVE
	export VMBlw = 38; # VOWEL_MOD_BELOW
	export VMPst = 39; # VOWEL_MOD_POST
	export VMPre = 23; # VOWEL_MOD_PRE
	export SMAbv = 41; # SYM_MOD_ABOVE
	export SMBlw = 42; # SYM_MOD_BELOW
	export FMAbv = 45; # CONS_FINAL_MOD UIPC = Top
	export FMBlw = 46; # CONS_FINAL_MOD UIPC = Bottom
	export FMPst = 47; # CONS_FINAL_MOD UIPC = Not_Applicable


	h = H \| HVM \| IS \| Sk;

	consonant_modifiers = CMAbv* CMBlw* ((h B \| SUB) CMAbv* CMBlw);
	medial_consonants = MPre? MAbv? MBlw? MPst?;
	dependent_vowels = VPre* VAbv* VBlw* VPst* \| H;
	vowel_modifiers = HVM? VMPre* VMAbv* VMBlw* VMPst*;
	final_consonants = FAbv* FBlw* FPst*;
	final_modifiers = FMAbv* FMBlw* \| FMPst?;

	complex_syllable_start = (R \| CS)? (B \| GB);
	complex_syllable_middle =
	consonant_modifiers
	medial_consonants
	dependent_vowels
	vowel_modifiers
	(Sk B)*
	;
	complex_syllable_tail =
	complex_syllable_middle
	final_consonants
	final_modifiers
	;
	number_joiner_terminated_cluster_tail = (HN N)* HN;
	numeral_cluster_tail = (HN N)+;
	symbol_cluster_tail = SMAbv+ SMBlw* \| SMBlw+;

	virama_terminated_cluster_tail =
	consonant_modifiers
	IS
	;
	virama_terminated_cluster =
	complex_syllable_start
	virama_terminated_cluster_tail
	;
	sakot_terminated_cluster_tail =
	complex_syllable_middle
	Sk
	;
	sakot_terminated_cluster =
	complex_syllable_start
	sakot_terminated_cluster_tail
	;
	standard_cluster =
	complex_syllable_start
	complex_syllable_tail
	;
	tail = complex_syllable_tail \| sakot_terminated_cluster_tail \| symbol_cluster_tail \| virama_terminated_cluster_tail;
	broken_cluster =
	R?
	(tail \| number_joiner_terminated_cluster_tail \| numeral_cluster_tail)
	;

	number_joiner_terminated_cluster = N number_joiner_terminated_cluster_tail;
	numeral_cluster = N numeral_cluster_tail?;
	symbol_cluster = (O \| GB \| SB) tail?;
	hieroglyph_cluster = SB* G HR? HM? SE* (J SB* (G HR? HM? SE)?);
	other = any;

	main := \|*
	virama_terminated_cluster ZWNJ? => { found_syllable (use_virama_terminated_cluster); };
	sakot_terminated_cluster ZWNJ? => { found_syllable (use_sakot_terminated_cluster); };
	standard_cluster ZWNJ? => { found_syllable (use_standard_cluster); };
	number_joiner_terminated_cluster ZWNJ? => { found_syllable (use_number_joiner_terminated_cluster); };
	numeral_cluster ZWNJ? => { found_syllable (use_numeral_cluster); };
	symbol_cluster ZWNJ? => { found_syllable (use_symbol_cluster); };
	hieroglyph_cluster ZWNJ? => { found_syllable (use_hieroglyph_cluster); };
	broken_cluster ZWNJ? => { found_syllable (use_broken_cluster); buffer->scratch_flags \|= HB_BUFFER_SCRATCH_FLAG_HAS_BROKEN_SYLLABLE; };
	other => { found_syllable (use_non_cluster); };
	*\|;


	}%%

	#define found_syllable(syllable_type) \
	HB_STMT_START { \
	if (0) fprintf (stderr, "syllable %u..%u %s\n", (ts).second.first, (te).second.first, #syllable_type); \
	for (unsigned i = (ts).second.first; i < (te).second.first; ++i) \
	info[i].syllable() = (syllable_serial << 4) \| syllable_type; \
	syllable_serial++; \
	if (syllable_serial == 16) syllable_serial = 1; \
	} HB_STMT_END


	template <typename Iter>
	struct machine_index_t :
	hb_iter_with_fallback_t<machine_index_t<Iter>,
	typename Iter::item_t>
	{
	machine_index_t (const Iter& it) : it (it) {}
	machine_index_t (const machine_index_t& o) : hb_iter_with_fallback_t<machine_index_t<Iter>,
	typename Iter::item_t> (),
	it (o.it), is_null (o.is_null) {}

	static constexpr bool is_random_access_iterator = Iter::is_random_access_iterator;
	static constexpr bool is_sorted_iterator = Iter::is_sorted_iterator;

	typename Iter::item_t __item__ () const { return *it; }
	typename Iter::item_t __item_at__ (unsigned i) const { return it[i]; }
	unsigned __len__ () const { return it.len (); }
	void __next__ () { ++it; }
	void __forward__ (unsigned n) { it += n; }
	void __prev__ () { --it; }
	void __rewind__ (unsigned n) { it -= n; }

	void operator = (unsigned n)
	{
	assert (n == 0);
	is_null = true;
	}
	explicit operator bool () { return !is_null; }

	void operator = (const machine_index_t& o)
	{
	is_null = o.is_null;
	unsigned index = (*it).first;
	unsigned n = (*o.it).first;
	if (index < n) it += n - index; else if (index > n) it -= index - n;
	}
	bool operator == (const machine_index_t& o) const
	{ return is_null ? o.is_null : !o.is_null && (it).first == (o.it).first; }
	bool operator != (const machine_index_t& o) const { return !(*this == o); }

	private:
	Iter it;
	bool is_null = false;
	};
	struct
	{
	template <typename Iter,
	hb_requires (hb_is_iterable (Iter))>
	machine_index_t<hb_iter_type<Iter>>
	operator () (Iter&& it) const
	{ return machine_index_t<hb_iter_type<Iter>> (hb_iter (it)); }
	}
	HB_FUNCOBJ (machine_index);



	static bool
	not_ccs_default_ignorable (const hb_glyph_info_t &i)
	{ return i.use_category() != USE(CGJ); }

	static inline void
	find_syllables_use (hb_buffer_t *buffer)
	{
	hb_glyph_info_t *info = buffer->info;
	auto p =
	+ hb_iter (info, buffer->len)
	\| hb_enumerate
	\| hb_filter ([] (const hb_glyph_info_t &i) { return not_ccs_default_ignorable (i); },
	hb_second)
	\| hb_filter ([&] (const hb_pair_t<unsigned, const hb_glyph_info_t &> p)
	{
	if (p.second.use_category() == USE(ZWNJ))
	for (unsigned i = p.first + 1; i < buffer->len; ++i)
	if (not_ccs_default_ignorable (info[i]))
	return !_hb_glyph_info_is_unicode_mark (&info[i]);
	return true;
	})
	\| hb_enumerate
	\| machine_index
	;
	auto pe = p + p.len ();
	auto eof = +pe;
	auto ts = +p;
	auto te = +p;
	unsigned int act HB_UNUSED;
	int cs;
	%%{
	write init;
	getkey (*p).second.second.use_category();
	}%%

	unsigned int syllable_serial = 1;
	%%{
	write exec;
	}%%
	}

	#undef found_syllable

	#endif /* HB_OT_SHAPER_USE_MACHINE_HH */