blob: 19629abebfe6436a75bf76a4af88484760dc7f2a [file] [log] [blame]
David Corbett205737a2018-10-12 16:54:54 -04001#!/usr/bin/python
2
3"""Generator of the function to prohibit certain vowel sequences.
4
Behdad Esfahbod6d40eb82018-10-23 02:51:42 -07005It creates ``_hb_preprocess_text_vowel_constraints``, which inserts dotted
David Corbett205737a2018-10-12 16:54:54 -04006circles into sequences prohibited by the USE script development spec.
7This function should be used as the ``preprocess_text`` of an
8``hb_ot_complex_shaper_t``.
David Corbett205737a2018-10-12 16:54:54 -04009"""
10
11from __future__ import absolute_import, division, print_function, unicode_literals
12
13import collections
14try:
15 from HTMLParser import HTMLParser
16 def write (s):
17 print (s.encode ('utf-8'), end='')
18except ImportError:
19 from html.parser import HTMLParser
20 def write (s):
21 sys.stdout.flush ()
22 sys.stdout.buffer.write (s.encode ('utf-8'))
23import itertools
24import io
25import sys
26
27if len (sys.argv) != 3:
Behdad Esfahbod6d40eb82018-10-23 02:51:42 -070028 print ('usage: ./gen-vowel-constraints.py HBIndicVowelConstraints.txt Scripts.txt', file=sys.stderr)
David Corbett205737a2018-10-12 16:54:54 -040029 sys.exit (1)
30
David Corbett205737a2018-10-12 16:54:54 -040031with io.open (sys.argv[2], encoding='utf-8') as f:
32 scripts_header = [f.readline () for i in range (2)]
33 scripts = {}
34 script_order = {}
35 for line in f:
36 j = line.find ('#')
37 if j >= 0:
38 line = line[:j]
39 fields = [x.strip () for x in line.split (';')]
40 if len (fields) == 1:
41 continue
42 uu = fields[0].split ('..')
43 start = int (uu[0], 16)
44 if len (uu) == 1:
45 end = start
46 else:
47 end = int (uu[1], 16)
48 script = fields[1]
49 for u in range (start, end + 1):
50 scripts[u] = script
51 if script not in script_order:
52 script_order[script] = start
53
54class ConstraintSet (object):
55 """A set of prohibited code point sequences.
56
57 Args:
58 constraint (List[int]): A prohibited code point sequence.
59
60 """
61 def __init__ (self, constraint):
62 # Either a list or a dictionary. As a list of code points, it
63 # represents a prohibited code point sequence. As a dictionary,
64 # it represents a set of prohibited sequences, where each item
65 # represents the set of prohibited sequences starting with the
66 # key (a code point) concatenated with any of the values
67 # (ConstraintSets).
68 self._c = constraint
69
70 def add (self, constraint):
71 """Add a constraint to this set."""
72 if not constraint:
73 return
74 first = constraint[0]
75 rest = constraint[1:]
76 if isinstance (self._c, list):
77 if constraint == self._c[:len (constraint)]:
78 self._c = constraint
79 elif self._c != constraint[:len (self._c)]:
80 self._c = {self._c[0]: ConstraintSet (self._c[1:])}
81 if isinstance (self._c, dict):
82 if first in self._c:
83 self._c[first].add (rest)
84 else:
85 self._c[first] = ConstraintSet (rest)
86
87 def _indent (self, depth):
88 return (' ' * depth).replace (' ', '\t')
89
90 def __str__ (self, index=0, depth=4):
91 s = []
92 indent = self._indent (depth)
93 if isinstance (self._c, list):
94 if len (self._c) == 0:
95 s.append ('{}matched = true;\n'.format (indent))
96 elif len (self._c) == 1:
97 s.append ('{}matched = 0x{:04X}u == buffer->cur ({}).codepoint;\n'.format (indent, next (iter (self._c)), index or ''))
98 else:
99 s.append ('{}if (0x{:04X}u == buffer->cur ({}).codepoint &&\n'.format (indent, self._c[0], index))
100 s.append ('{}buffer->idx + {} < count &&\n'.format (self._indent (depth + 2), len (self._c)))
101 for i, cp in enumerate (self._c[1:], start=1):
102 s.append ('{}0x{:04X}u == buffer->cur ({}).codepoint{}\n'.format (
103 self._indent (depth + 2), cp, index + i, ')' if i == len (self._c) - 1 else ' &&'))
104 s.append ('{}{{\n'.format (indent))
105 for i in range (len (self._c)):
106 s.append ('{}buffer->next_glyph ();\n'.format (self._indent (depth + 1)))
107 s.append ('{}buffer->output_glyph (0x25CCu);\n'.format (self._indent (depth + 1)))
108 s.append ('{}}}\n'.format (indent))
109 else:
110 s.append ('{}switch (buffer->cur ({}).codepoint)\n'.format(indent, index or ''))
111 s.append ('{}{{\n'.format (indent))
112 cases = collections.defaultdict (set)
113 for first, rest in sorted (self._c.items ()):
114 cases[rest.__str__ (index + 1, depth + 2)].add (first)
115 for body, labels in sorted (cases.items (), key=lambda b_ls: sorted (b_ls[1])[0]):
116 for i, cp in enumerate (sorted (labels)):
117 if i % 4 == 0:
118 s.append (self._indent (depth + 1))
119 else:
120 s.append (' ')
121 s.append ('case 0x{:04X}u:{}'.format (cp, '\n' if i % 4 == 3 else ''))
122 if len (labels) % 4 != 0:
123 s.append ('\n')
124 s.append (body)
125 s.append ('{}break;\n'.format (self._indent (depth + 2)))
126 s.append ('{}}}\n'.format (indent))
127 return ''.join (s)
128
Behdad Esfahbod6d40eb82018-10-23 02:51:42 -0700129constraints = {}
130with io.open (sys.argv[1], encoding='utf-8') as f:
131 constraints_header = [f.readline ().strip () for i in range (2)]
132 for line in f:
133 j = line.find ('#')
134 if j >= 0:
135 line = line[:j]
136 constraint = [int (cp, 16) for cp in line.split (';')[0].split ()]
137 if not constraint: continue
138 assert 2 <= len (constraint), 'Prohibited sequence is too short: {}'.format (constraint)
139 script = scripts[constraint[0]]
140 if script in constraints:
141 constraints[script].add (constraint)
142 else:
143 constraints[script] = ConstraintSet (constraint)
144 assert constraints, 'No constraints found'
David Corbett205737a2018-10-12 16:54:54 -0400145
146print ('/* == Start of generated functions == */')
147print ('/*')
148print (' * The following functions are generated by running:')
149print (' *')
150print (' * %s use Scripts.txt' % sys.argv[0])
151print (' *')
152print (' * on files with these headers:')
153print (' *')
Behdad Esfahbod6d40eb82018-10-23 02:51:42 -0700154for line in constraints_header:
155 print (' * %s' % line.strip ())
156print (' *')
David Corbett205737a2018-10-12 16:54:54 -0400157for line in scripts_header:
158 print (' * %s' % line.strip ())
159print (' */')
160print ()
Behdad Esfahbod6d40eb82018-10-23 02:51:42 -0700161print ('#include "hb-ot-shape-complex-vowel-constraints.hh"')
David Corbett205737a2018-10-12 16:54:54 -0400162print ()
David Corbett205737a2018-10-12 16:54:54 -0400163print ('static void')
164print ('_output_with_dotted_circle (hb_buffer_t *buffer)')
165print ('{')
166print (' hb_glyph_info_t &dottedcircle = buffer->output_glyph (0x25CCu);')
167print (' _hb_glyph_info_reset_continuation (&dottedcircle);')
168print ()
169print (' buffer->next_glyph ();')
170print ('}')
171print ()
172
Behdad Esfahbod6d40eb82018-10-23 02:51:42 -0700173print ('void')
174print ('_hb_preprocess_text_vowel_constraints (const hb_ot_shape_plan_t *plan,')
175print ('\t\t\t\t hb_buffer_t *buffer,')
176print ('\t\t\t\t hb_font_t *font)')
David Corbett205737a2018-10-12 16:54:54 -0400177print ('{')
178print (' /* UGLY UGLY UGLY business of adding dotted-circle in the middle of')
179print (' * vowel-sequences that look like another vowel. Data for each script')
180print (' * collected from the USE script development spec.')
181print (' *')
182print (' * https://github.com/harfbuzz/harfbuzz/issues/1019')
183print (' */')
184print (' bool processed = false;')
185print (' buffer->clear_output ();')
186print (' unsigned int count = buffer->len;')
187print (' switch ((unsigned) buffer->props.script)')
188print (' {')
189
Behdad Esfahbod6d40eb82018-10-23 02:51:42 -0700190for script, constraints in sorted (constraints.items (), key=lambda s_c: script_order[s_c[0]]):
David Corbett205737a2018-10-12 16:54:54 -0400191 print (' case HB_SCRIPT_{}:'.format (script.upper ()))
192 print (' for (buffer->idx = 0; buffer->idx + 1 < count && buffer->successful;)')
193 print (' {')
194 print ('\tbool matched = false;')
195 write (str (constraints))
196 print ('\tbuffer->next_glyph ();')
197 print ('\tif (matched) _output_with_dotted_circle (buffer);')
198 print (' }')
199 print (' processed = true;')
200 print (' break;')
201 print ()
202
203print (' default:')
204print (' break;')
205print (' }')
206print (' if (processed)')
207print (' {')
208print (' if (buffer->idx < count)')
209print (' buffer->next_glyph ();')
210print (' if (likely (buffer->successful))')
211print (' buffer->swap_buffers ();')
212print (' }')
213print ('}')
214
215print ()
David Corbett205737a2018-10-12 16:54:54 -0400216print ('/* == End of generated functions == */')