1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
|
if not modules then modules = { } end modules ['simurgh-unibidi-core'] = {
version = 0.01,
comment = "unicode bidi",
author = "Vafa Khalighi",
copyright = "Vafa Khalighi",
license = "see simurgh package documentation",
derived = "derived from typo-dha by Hans Hagen"
}
-- Some analysis:
--
-- 1. Assuming the reading- vs word-order distinction (bidi-char types) is governing;
-- 2. Assuming that 'PARSI' represents an actual parsi string in raw input order, not word-order;
-- 3. Assuming that 'ISRAP' represent the correct RL word order;
--
-- Then we have, with input: LATIN PARSI
--
-- \simurgh@textdir TLT LATIN PARSI => LATIN ISRAP
-- \simurgh@textdir TRT LATIN PARSI => LATIN ISRAP
-- \simurgh@textdir TRT LRO LATIN PARSI => LATIN PARSI
-- \simurgh@textdir TLT LRO LATIN PARSI => LATIN PARSI
-- \simurgh@textdir TLT RLO LATIN PARSI => NITAL PARSI
-- \simurgh@textdir TRT RLO LATIN PARSI => NITAL PARSI
-- elseif d == "es" then -- European Number Separator
-- elseif d == "et" then -- European Number Terminator
-- elseif d == "cs" then -- Common Number Separator
-- elseif d == "nsm" then -- Non-Spacing Mark
-- elseif d == "bn" then -- Boundary Neutral
-- elseif d == "b" then -- Paragraph Separator
-- elseif d == "s" then -- Segment Separator
-- elseif d == "ws" then -- Whitespace
-- elseif d == "on" then -- Other Neutrals
-- todo : delayed inserts here
-- todo : get rid of local functions here
-- beware: math adds whatsits afterwards so that will mess things up
-- todo : use new dir functions
-- todo : make faster
-- todo : move dir info into nodes
-- todo : swappable tables and floats i.e. start-end overloads (probably loop in builders)
-- todo : check if we still have crashes in luatex when non-matched (used to be the case)
local nodes, node = nodes, node
local trace_directions = false trackers.register("typesetters.directions.default", function(v) trace_directions = v end)
local report_directions = logs.reporter("typesetting","text directions")
local insert_node_before = nodes.insert_before
local insert_node_after = nodes.insert_after
local remove_node = nodes.remove
local end_of_math = nodes.end_of_math
local nodepool = nodes.pool
local nodecodes = nodes.nodecodes
local whatcodes = nodes.whatcodes
local mathcodes = nodes.mathcodes
local glyph_code = nodecodes.glyph
local whatsit_code = nodecodes.whatsit
local math_code = nodecodes.math
local penalty_code = nodecodes.penalty
local kern_code = nodecodes.kern
local glue_code = nodecodes.glue
local hlist_code = nodecodes.hlist
local vlist_code = nodecodes.vlist
local localpar_code = whatcodes.localpar
local dir_code = whatcodes.dir
local new_textdir = nodepool.textdir
local hasbit = number.hasbit
local formatters = string.formatters
local insert = table.insert
local fonthashes = fonts.hashes
local fontdata = fonthashes.identifiers
local fontchar = fonthashes.characters
local chardirections = characters.directions
local charmirrors = characters.mirrors
local charclasses = characters.textclasses
local directions = typesetters.directions
local getglobal = directions.getglobal
local a_state = attributes.private('state')
local a_directions = attributes.private('directions')
local strip = false
local s_isol = fonts.analyzers.states.isol
local function stopdir(finish)
return new_textdir(finish == "TRT" and "-TRT" or "-TLT")
end
local function startdir(finish)
return new_textdir(finish == "TRT" and "+TRT" or "+TLT")
end
local function process(namespace,attribute,start)
local head = start
local current = head
local inserted = nil
local finish = nil
local autodir = 0
local embedded = 0
local override = 0
local pardir = 1
local textdir = 1
local done = false
local finished = nil
local finidir = nil
local stack = { }
local top = 0
local obsolete = { }
local lro = false
local lro = false
local prevattr = false
local fences = { }
local function finish_auto_before()
head, inserted = insert_node_before(head,current,stopdir(finish))
finished, finidir, autodir = inserted, finish, 0
finish, done = nil, true
end
local function finish_auto_after()
head, current = insert_node_after(head,current,stopdir(finish))
finished, finidir, autodir = current, finish, 0
finish, done = nil, true
end
local function force_auto_left_before(direction)
if finish then
head, inserted = insert_node_before(head,current,stopdir(finish))
finished = inserted
finidir = finish
end
if embedded >= 0 then
finish, autodir = "TLT", 1
else
finish, autodir = "TRT", -1
end
done = true
if finidir == finish then
head = remove_node(head,finished,true)
else
head, inserted = insert_node_before(head,current,startdir(finish))
end
end
local function force_auto_right_before(direction)
if finish then
head, inserted = insert_node_before(head,current,stopdir(finish))
finished = inserted
finidir = finish
end
if embedded <= 0 then
finish, autodir, done = "TRT", -1
else
finish, autodir, done = "TLT", 1
end
done = true
if finidir == finish then
head = remove_node(head,finished,true)
else
head, inserted = insert_node_before(head,current,startdir(finish))
end
end
local function nextisright(current)
current = current.next
local id = current.id
if id == glyph_code then
local character = current.char
local direction = chardirections[character]
return direction == "r" or direction == "al" or direction == "an"
end
end
local function previsright(current)
current = current.prev
local id = current.id
if id == glyph_code then
local char = current.char
local direction = chardirections[character]
return direction == "r" or direction == "al" or direction == "an"
end
end
while current do
local id = current.id
if id == math_code then
current = end_of_math(current.next).next
else
local attr = current[attribute]
if attr and attr > 0 and attr ~= prevattr then
if not getglobal(a) then
lro, rlo = false, false
end
prevattr = attr
end
if id == glyph_code then
if attr and attr > 0 then
local character = current.char
local direction = chardirections[character]
local reversed = false
if rlo or override > 0 then
if direction == "l" then
direction = "r"
reversed = true
end
elseif lro or override < 0 then
if direction == "r" or direction == "al" then
current[a_state] = s_isol
direction = "l"
reversed = true
end
end
if direction == "on" then
local mirror = charmirrors[character]
if mirror and fontchar[current.font][mirror] then
local class = charclasses[character]
if class == "open" then
if nextisright(current) then
if autodir >= 0 then
force_auto_right_before(direction)
end
current.char = mirror
done = true
elseif autodir < 0 then
current.char = mirror
done = true
else
mirror = false
end
local fencedir = autodir == 0 and textdir or autodir
fences[#fences+1] = fencedir
elseif class == "close" and #fences > 0 then
local fencedir = fences[#fences]
fences[#fences] = nil
if fencedir < 0 then
current.char = mirror
done = true
force_auto_right_before(direction)
else
mirror = false
end
elseif autodir < 0 then
current.char = mirror
done = true
else
mirror = false
end
end
elseif direction == "l" then
if autodir <= 0 then -- could be option
force_auto_left_before(direction)
end
elseif direction == "r" then
if autodir >= 0 then
force_auto_right_before(direction)
end
elseif direction == "en" then -- european number
if autodir <= 0 then -- could be option
force_auto_left_before(direction)
end
elseif direction == "al" then -- arabic number
if autodir >= 0 then
force_auto_right_before(direction)
end
elseif direction == "an" then -- arabic number
if autodir >= 0 then
force_auto_right_before(direction)
end
elseif direction == "lro" then -- Left-to-Right Override -> right becomes left
top = top + 1
stack[top] = { override, embedded }
override = -1
obsolete[#obsolete+1] = current
elseif direction == "rlo" then -- Right-to-Left Override -> left becomes right
top = top + 1
stack[top] = { override, embedded }
override = 1
obsolete[#obsolete+1] = current
elseif direction == "lre" then -- Left-to-Right Embedding -> TLT
top = top + 1
stack[top] = { override, embedded }
embedded = 1
obsolete[#obsolete+1] = current
elseif direction == "rle" then -- Right-to-Left Embedding -> TRT
top = top + 1
stack[top] = { override, embedded }
embedded = -1
obsolete[#obsolete+1] = current
elseif direction == "pdf" then -- Pop Directional Format
if top > 0 then
local s = stack[top]
override, embedded = s[1], s[2]
top = top - 1
end
obsolete[#obsolete+1] = current
end
else
-- we do nothing
end
elseif id == whatsit_code then
local subtype = current.subtype
if subtype == localpar_code then
local dir = current.dir
if dir == 'TRT' then
autodir = -1
elseif dir == 'TLT' then
autodir = 1
end
pardir = autodir
textdir = pardir
elseif subtype == dir_code then
-- todo: also treat as lro|rlo and stack
if finish then
finish_auto_before()
end
local dir = current.dir
if dir == "+TRT" then
finish, autodir = "TRT", -1
elseif dir == "-TRT" then
finish, autodir = nil, 0
elseif dir == "+TLT" then
finish, autodir = "TLT", 1
elseif dir == "-TLT" then
finish, autodir = nil, 0
end
textdir = autodir
else
if finish then
finish_auto_before()
end
end
elseif finish then
finish_auto_before()
end
local cn = current.next
if cn then
-- we're okay
elseif finish then
finish_auto_after()
end
current = cn
end
end
if done and strip then
local n = #obsolete
if n > 0 then
for i=1,n do
remove_node(head,obsolete[i],true)
end
report_directions("%s character nodes removed",n)
end
end
return head, done
end
directions.installhandler(interfaces.variables.default,process)
|
