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
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
|
if not modules then modules = { } end modules ['scite-ctx-bidi'] = {
version = 1.001,
comment = "companion to scite-ctx.lua",
author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
copyright = "PRAGMA ADE / ConTeXt Development Team",
license = "see context related readme files",
comment = "Unicode bidi (sort of) variant c",
}
-- Partial comment from typo-duc.lua:
--
-- This is a follow up on typo-dua which itself is a follow up on t-bidi by Khaled Hosny which
-- in turn is based on minibidi.c from Arabeyes. This is a further optimizations, as well as
-- an update on some recent unicode bidi developments. There is (and will) also be more control
-- added. As a consequence this module is somewhat slower than its precursor which itself is
-- slower than the one-pass bidi handler. This is also a playground and I might add some plugin
-- support. However, in the meantime performance got a bit better and this third variant is again
-- some 10% faster than the second variant.
--
-- ... some patches and updates applied
-- ... some code can be removed
-- ... has to be kept in sync with context
-- ... mtxrun --script interface
--
-- ... this feature is more fun than useful
-- ... this way we can use it to check what scite / uniscribe sees (as scintila is weak on
-- bidi selection)
local setmetatable = setmetatable
local data = require("context.lexers.data.scite-context-data-bidi")
local directiondata = data.directions
local mirrordata = data.mirrors
local textclassdata = data.textclasses
-- setmetatable(directiondata,{ __index = function(t,k) local v = "l" t[k] = v return v end })
local maximum_stack = 0xFF -- unicode: 60, will be jumped to 125, we don't care too much
local analyze_fences = false
local whitespace = {
lre = true,
rle = true,
lro = true,
rlo = true,
pdf = true,
bn = true,
ws = true,
}
local b_s_ws_on = {
b = true,
s = true,
ws = true,
on = true
}
local mt_space = { __index = { char = 0x0020, direction = "ws", original = "ws", level = 0 } }
----- mt_lre = { __index = { char = 0x202A, direction = "lre", original = "lre", level = 0 } }
----- mt_rle = { __index = { char = 0x202B, direction = "rle", original = "rle", level = 0 } }
----- mt_pdf = { __index = { char = 0x202C, direction = "pdf", original = "pdf", level = 0 } }
----- mt_object = { __index = { char = 0xFFFC, direction = "on", original = "on", level = 0 } }
local stack = { } -- shared
setmetatable(stack, { __index = function(t,k) local v = { } t[k] = v return v end })
local function build_list(list)
-- P1
local size = #list
for i=1,size do
local chr = list[i]
if chr == " " then
list[i] = setmetatable({ },mt_space)
else
local dir = directiondata[chr] or "l"
list[i] = { char = chr, direction = dir, original = dir, level = 0 }
end
end
return list, size
end
local function resolve_fences(list,size,start,limit)
-- N0: funny effects, not always better, so it's an option
local nofstack = 0
for i=start,limit do
local entry = list[i]
if entry.direction == "on" then
local char = entry.char
local mirror = mirrordata[char]
if mirror then
local class = textclassdata[char]
entry.mirror = mirror
entry.class = class
if class == "open" then
nofstack = nofstack + 1
local stacktop = stack[nofstack]
stacktop[1] = mirror
stacktop[2] = i
stacktop[3] = false -- not used
elseif nofstack == 0 then
-- skip
elseif class == "close" then
while nofstack > 0 do
local stacktop = stack[nofstack]
if stacktop[1] == char then
local open = stacktop[2]
local close = i
list[open ].paired = close
list[close].paired = open
break
else
-- do we mirror or not
end
nofstack = nofstack - 1
end
end
end
end
end
end
local function get_baselevel(list,size,direction)
if direction == "TRT" then
return 1, "TRT", true
elseif direction == "TLT" then
return 0, "TLT", true
end
-- P2, P3:
for i=1,size do
local entry = list[i]
local direction = entry.direction
if direction == "r" or direction == "al" then -- and an ?
return 1, "TRT", true
elseif direction == "l" then
return 0, "TLT", true
end
end
return 0, "TLT", false
end
local function resolve_explicit(list,size,baselevel)
-- if list.rle or list.lre or list.rlo or list.lro then
-- X1
local level = baselevel
local override = "on"
local nofstack = 0
for i=1,size do
local entry = list[i]
local direction = entry.direction
-- X2
if direction == "rle" then
if nofstack < maximum_stack then
nofstack = nofstack + 1
local stacktop = stack[nofstack]
stacktop[1] = level
stacktop[2] = override
level = level + (level % 2 == 1 and 2 or 1) -- least_greater_odd(level)
override = "on"
entry.level = level
entry.direction = "bn"
entry.remove = true
end
-- X3
elseif direction == "lre" then
if nofstack < maximum_stack then
nofstack = nofstack + 1
local stacktop = stack[nofstack]
stacktop[1] = level
stacktop[2] = override
level = level + (level % 2 == 1 and 1 or 2) -- least_greater_even(level)
override = "on"
entry.level = level
entry.direction = "bn"
entry.remove = true
end
-- X4
elseif direction == "rlo" then
if nofstack < maximum_stack then
nofstack = nofstack + 1
local stacktop = stack[nofstack]
stacktop[1] = level
stacktop[2] = override
level = level + (level % 2 == 1 and 2 or 1) -- least_greater_odd(level)
override = "r"
entry.level = level
entry.direction = "bn"
entry.remove = true
end
-- X5
elseif direction == "lro" then
if nofstack < maximum_stack then
nofstack = nofstack + 1
local stacktop = stack[nofstack]
stacktop[1] = level
stacktop[2] = override
level = level + (level % 2 == 1 and 1 or 2) -- least_greater_even(level)
override = "l"
entry.level = level
entry.direction = "bn"
entry.remove = true
end
-- X7
elseif direction == "pdf" then
if nofstack < maximum_stack then
local stacktop = stack[nofstack]
level = stacktop[1]
override = stacktop[2]
nofstack = nofstack - 1
entry.level = level
entry.direction = "bn"
entry.remove = true
end
-- X6
else
entry.level = level
if override ~= "on" then
entry.direction = override
end
end
end
-- else
-- for i=1,size do
-- list[i].level = baselevel
-- end
-- end
-- X8 (reset states and overrides after paragraph)
end
local function resolve_weak(list,size,start,limit,orderbefore,orderafter)
-- W1: non spacing marks get the direction of the previous character
-- if list.nsm then
for i=start,limit do
local entry = list[i]
if entry.direction == "nsm" then
if i == start then
entry.direction = orderbefore
else
entry.direction = list[i-1].direction
end
end
end
-- end
-- W2: mess with numbers and arabic
-- if list.en then
for i=start,limit do
local entry = list[i]
if entry.direction == "en" then
for j=i-1,start,-1 do
local prev = list[j]
local direction = prev.direction
if direction == "al" then
entry.direction = "an"
break
elseif direction == "r" or direction == "l" then
break
end
end
end
end
-- end
-- W3
-- if list.al then
for i=start,limit do
local entry = list[i]
if entry.direction == "al" then
entry.direction = "r"
end
end
-- end
-- W4: make separators number
-- if list.es or list.cs then
-- skip
-- if false then
if false then
for i=start+1,limit-1 do
local entry = list[i]
local direction = entry.direction
if direction == "es" then
if list[i-1].direction == "en" and list[i+1].direction == "en" then
entry.direction = "en"
end
elseif direction == "cs" then
local prevdirection = list[i-1].direction
if prevdirection == "en" then
if list[i+1].direction == "en" then
entry.direction = "en"
end
elseif prevdirection == "an" and list[i+1].direction == "an" then
entry.direction = "an"
end
end
end
else -- only more efficient when we have es/cs
local runner = start + 2
local before = list[start]
local entry = list[start + 1]
local after = list[runner]
while after do
local direction = entry.direction
if direction == "es" then
if before and before.direction == "en" and after.direction == "en" then
entry.direction = "en"
end
elseif direction == "cs" then
local prevdirection = before and before.direction
if prevdirection == "en" then
if after.direction == "en" then
entry.direction = "en"
end
elseif prevdirection == "an" and after.direction == "an" then
entry.direction = "an"
end
end
before = current
current = after
after = list[runner]
runner = runner + 1
end
end
-- end
-- W5
-- if list.et then
local i = start
while i <= limit do
if list[i].direction == "et" then
local runstart = i
local runlimit = runstart
for i=runstart,limit do
if list[i].direction == "et" then
runlimit = i
else
break
end
end
local rundirection = runstart == start and sor or (runstart > 1 and list[runstart-1].direction)
if rundirection ~= "en" then
rundirection = runlimit == limit and orderafter or list[runlimit+1].direction
end
if rundirection == "en" then
for j=runstart,runlimit do
list[j].direction = "en"
end
end
i = runlimit
end
i = i + 1
end
-- end
-- W6
-- if list.es or list.cs or list.et then
for i=start,limit do
local entry = list[i]
local direction = entry.direction
if direction == "es" or direction == "et" or direction == "cs" then
entry.direction = "on"
end
end
-- end
-- W7
for i=start,limit do
local entry = list[i]
if entry.direction == "en" then
local prev_strong = orderbefore
for j=i-1,start,-1 do
local direction = list[j].direction
if direction == "l" or direction == "r" then
prev_strong = direction
break
end
end
if prev_strong == "l" then
entry.direction = "l"
end
end
end
end
local function resolve_neutral(list,size,start,limit,orderbefore,orderafter)
-- N1, N2
for i=start,limit do
local entry = list[i]
if b_s_ws_on[entry.direction] then
-- this needs checking
local leading_direction, trailing_direction, resolved_direction
local runstart = i
local runlimit = runstart
for j=runstart+1,limit do
if b_s_ws_on[list[j].direction] then
runlimit = j
else
break
end
end
if runstart == start then
leading_direction = orderbefore
else
leading_direction = list[runstart-1].direction
if leading_direction == "en" or leading_direction == "an" then
leading_direction = "r"
end
end
if runlimit == limit then
trailing_direction = orderafter
else
trailing_direction = list[runlimit+1].direction
if trailing_direction == "en" or trailing_direction == "an" then
trailing_direction = "r"
end
end
if leading_direction == trailing_direction then
-- N1
resolved_direction = leading_direction
else
-- N2 / does the weird period
resolved_direction = entry.level % 2 == 1 and "r" or "l"
end
for j=runstart,runlimit do
list[j].direction = resolved_direction
end
i = runlimit
end
i = i + 1
end
end
local function resolve_implicit(list,size,start,limit,orderbefore,orderafter,baselevel)
for i=start,limit do
local entry = list[i]
local level = entry.level
local direction = entry.direction
if level % 2 ~= 1 then -- even
-- I1
if direction == "r" then
entry.level = level + 1
elseif direction == "an" or direction == "en" then
entry.level = level + 2
end
else
-- I2
if direction == "l" or direction == "en" or direction == "an" then
entry.level = level + 1
end
end
end
end
local function resolve_levels(list,size,baselevel,analyze_fences)
-- X10
local start = 1
while start < size do
local level = list[start].level
local limit = start + 1
while limit < size and list[limit].level == level do
limit = limit + 1
end
local prev_level = start == 1 and baselevel or list[start-1].level
local next_level = limit == size and baselevel or list[limit+1].level
local orderbefore = (level > prev_level and level or prev_level) % 2 == 1 and "r" or "l"
local orderafter = (level > next_level and level or next_level) % 2 == 1 and "r" or "l"
-- W1 .. W7
resolve_weak(list,size,start,limit,orderbefore,orderafter)
-- N0
if analyze_fences then
resolve_fences(list,size,start,limit)
end
-- N1 .. N2
resolve_neutral(list,size,start,limit,orderbefore,orderafter)
-- I1 .. I2
resolve_implicit(list,size,start,limit,orderbefore,orderafter,baselevel)
start = limit
end
-- L1
for i=1,size do
local entry = list[i]
local direction = entry.original
-- (1)
if direction == "s" or direction == "b" then
entry.level = baselevel
-- (2)
for j=i-1,1,-1 do
local entry = list[j]
if whitespace[entry.original] then
entry.level = baselevel
else
break
end
end
end
end
-- (3)
for i=size,1,-1 do
local entry = list[i]
if whitespace[entry.original] then
entry.level = baselevel
else
break
end
end
-- L4
if analyze_fences then
for i=1,size do
local entry = list[i]
if entry.level % 2 == 1 then
if entry.mirror and not entry.paired then
entry.mirror = false
end
elseif entry.mirror then
entry.mirror = false
end
end
else
for i=1,size do
local entry = list[i]
if entry.level % 2 == 1 then
local mirror = mirrordata[entry.char]
if mirror then
entry.mirror = mirror
end
end
end
end
end
local function process(head,direction)
local list, size = build_list(head)
local baselevel = get_baselevel(list,size,direction)
resolve_explicit(list,size,baselevel)
resolve_levels(list,size,baselevel,analyze_fences)
return list, size
end
return {
process = process,
}
|