summaryrefslogtreecommitdiff
path: root/Master/texmf-dist/tex/luatex/optex/base/optex.lua
blob: 8201b8b3061aa40d709a401a0f22db1ae9bb0ccf (plain)
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
-- This is part of OpTeX project, see http://petr.olsak.net/optex

-- The basic lua functions and declarations used in \OpTeX/ are here

-- GENERAL

-- Error function used by following functions for critical errors.
local function err(message)
    error("\nerror: "..message.."\n")
end
--
-- For a `\chardef`'d, `\countdef`'d, etc., csname return corresponding register
-- number. The responsibility of providing a `\XXdef`'d name is on the caller.
function registernumber(name)
    return token.create(name).index
end
--
-- ALLOCATORS
alloc = alloc or {}
--
-- An attribute allocator in Lua that cooperates with normal \OpTeX/ allocator.
local attributes = {}
local attribute_max = registernumber("_maiattribute")
function alloc.new_attribute(name)
    local cnt = tex.count["_attributealloc"] + 1
    if cnt > attribute_max then
        tex.error("No room for a new attribute")
    else
        tex.setcount("global", "_attributealloc", cnt)
        texio.write_nl("log", '"'..name..'"=\\attribute'..tostring(cnt))
        attributes[name] = cnt
        return cnt
    end
end
--
-- CALLBACKS
callback = callback or {}
--
-- Save `callback.register` function for internal use.
local callback_register = callback.register
function callback.register(name, fn)
    err("direct registering of callbacks is forbidden, use 'callback.add_to_callback'")
end
--
-- Table with lists of functions for different callbacks.
local callback_functions = {}
-- Table that maps callback name to a list of descriptions of its added
-- functions. The order corresponds with `callback_functions`.
local callback_description = {}
--
-- Table used to differentiate user callbacks from standard callbacks. Contains
-- user callbacks as keys.
local user_callbacks = {}
-- Table containing default functions for callbacks, which are called if either
-- a user created callback is defined, but doesn't have added functions or for
-- standard callbacks that are \"extended" (see `mlist_to_hlist` and its pre/post
-- filters below).
local default_functions = {}
--
-- Table that maps standard (and later user) callback names to their types.
local callback_types = {
    -- file discovery
    find_read_file     = "exclusive",
    find_write_file    = "exclusive",
    find_font_file     = "data",
    find_output_file   = "data",
    find_format_file   = "data",
    find_vf_file       = "data",
    find_map_file      = "data",
    find_enc_file      = "data",
    find_pk_file       = "data",
    find_data_file     = "data",
    find_opentype_file = "data",
    find_truetype_file = "data",
    find_type1_file    = "data",
    find_image_file    = "data",

    open_read_file     = "exclusive",
    read_font_file     = "exclusive",
    read_vf_file       = "exclusive",
    read_map_file      = "exclusive",
    read_enc_file      = "exclusive",
    read_pk_file       = "exclusive",
    read_data_file     = "exclusive",
    read_truetype_file = "exclusive",
    read_type1_file    = "exclusive",
    read_opentype_file = "exclusive",

    -- data processing
    process_input_buffer  = "data",
    process_output_buffer = "data",
    process_jobname       = "data",

    -- node list processing
    contribute_filter      = "simple",
    buildpage_filter       = "simple",
    build_page_insert      = "exclusive",
    pre_linebreak_filter   = "list",
    linebreak_filter       = "exclusive",
    append_to_vlist_filter = "exclusive",
    post_linebreak_filter  = "reverselist",
    hpack_filter           = "list",
    vpack_filter           = "list",
    hpack_quality          = "list",
    vpack_quality          = "list",
    process_rule           = "exclusive",
    pre_output_filter      = "list",
    hyphenate              = "simple",
    ligaturing             = "simple",
    kerning                = "simple",
    insert_local_par       = "simple",
    mlist_to_hlist         = "exclusive",

    -- information reporting
    pre_dump             = "simple",
    start_run            = "simple",
    stop_run             = "simple",
    start_page_number    = "simple",
    stop_page_number     = "simple",
    show_error_hook      = "simple",
    show_error_message   = "simple",
    show_lua_error_hook  = "simple",
    start_file           = "simple",
    stop_file            = "simple",
    call_edit            = "simple",
    finish_synctex       = "simple",
    wrapup_run           = "simple",

    -- pdf related
    finish_pdffile            = "data",
    finish_pdfpage            = "data",
    page_order_index          = "data",
    process_pdf_image_content = "data",

    -- font related
    define_font     = "exclusive",
    glyph_not_found = "exclusive",
    glyph_info      = "exclusive",

    -- undocumented
    glyph_stream_provider = "exclusive",
}
--
-- Return a list containing descriptions of added callback functions for
-- specific callback.
function callback.callback_descriptions(name)
    return callback_description[name] or {}
end

local valid_callback_types = {
    exclusive = true,
    simple = true,
    data = true,
    list = true,
    reverselist = true,
}
--
-- Create a user callback that can only be called manually using
-- `call_callback`. A default function is only needed by "exclusive" callbacks.
function callback.create_callback(name, cbtype, default)
    if callback_types[name] then
        err("cannot create callback '"..name.."' - it already exists")
    elseif not valid_callback_types[cbtype] then
        err("cannot create callback '"..name.. "' with invalid callback type '"..cbtype.."'")
    elseif ctype == "exclusive" and not default then
        err("unable to create exclusive callback '"..name.."', default function is required")
    end

    callback_types[name] = cbtype
    default_functions[name] = default or nil
    user_callbacks[name] = true
end
--
-- Add a function to the list of functions executed when callback is called.
-- For standard luatex callback a proxy function that calls our machinery is
-- registered as the real callback function. This doesn't happen for user
-- callbacks, that are called manually by user using `call_callback` or for
-- standard callbacks that have default functions -- like `mlist_to_hlist` (see
-- below).
function callback.add_to_callback(name, fn, description)
    if user_callbacks[name] or callback_functions[name] or default_functions[name] then
        -- either:
        --  a) user callback - no need to register anything
        --  b) standard callback that has already been registered
        --  c) standard callback with default function registered separately
        --     (mlist_to_hlist)
    elseif callback_types[name] then
        -- This is a standard luatex callback with first function being added,
        -- register a proxy function as a real callback. Assert, so we know
        -- when things break, like when callbacks get redefined by future
        -- luatex.
        assert(callback_register(name, function(...)
            return callback.call_callback(name, ...)
        end))
    else
        err("cannot add to callback '"..name.."' - no such callback exists")
    end

    -- add function to callback list for this callback
    callback_functions[name] = callback_functions[name] or {}
    table.insert(callback_functions[name], fn)

    -- add description to description list
    callback_description[name] = callback_description[name] or {}
    table.insert(callback_description[name], description)
end
--
-- Remove a function from the list of functions executed when callback is
-- called. If last function in the list is removed delete the list entirely.
function callback.remove_from_callback(name, description)
    local descriptions = callback_description[name]
    local index
    for i, desc in ipairs(descriptions) do
        if desc == description then
            index = i
            break
        end
    end

    table.remove(descriptions, index)
    local fn = table.remove(callback_functions[name], index)

    if #descriptions == 0 then
        -- Delete the list entirely to allow easy checking of "truthiness".
        callback_functions[name] = nil

        if not user_callbacks[name] and not default_functions[name] then
            -- this is a standard callback with no added functions and no
            -- default function (i.e. not mlist_to_hlist), restore standard
            -- behaviour by unregistering.
            callback_register(name, nil)
        end
    end

    return fn, description
end
--
-- helper iterator generator for iterating over reverselist callback functions
local function reverse_ipairs(t)
    local i, n = #t + 1, 1
    return function()
        i = i - 1
        if i >= n then
            return i, t[i]
        end
    end
end
--
-- Call all functions added to callback. This function handles standard
-- callbacks as well as user created callbacks. It can happen that this
-- function is called when no functions were added to callback -- like for user
-- created callbacks or `mlist_to_hlist` (see below), these are handled either
-- by a default function (like for `mlist_to_hlist` and those user created
-- callbacks that set a default function) or by doing nothing for empty
-- function list.
function callback.call_callback(name, ...)
    local cbtype = callback_types[name]
    -- either take added functions or the default function if there is one
    local functions = callback_functions[name] or {default_functions[name]}

    if cbtype == nil then
        err("cannot call callback '"..name.."' - no such callback exists")
    elseif cbtype == "exclusive" then
        -- only one function, atleast default function is guaranteed by
        -- create_callback
        return functions[1](...)
    elseif cbtype == "simple" then
        -- call all functions one after another, no passing of data
        for _, fn in ipairs(functions) do
            fn(...)
        end
        return
    elseif cbtype == "data" then
        -- pass data (first argument) from one function to other, while keeping
        -- other arguments
        local data = (...)
        for _, fn in ipairs(functions) do
            data = fn(data, select(2, ...))
        end
        return data
    end

    -- list and reverselist are like data, but "true" keeps data (head node)
    -- unchanged and "false" ends the chain immediately
    local iter
    if cbtype == "list" then
        iter = ipairs
    elseif cbtype == "reverselist" then
        iter = reverse_ipairs
    end

    local head = (...)
    local new_head
    local changed = false
    for _, fn in iter(functions) do
        new_head = fn(head, select(2, ...))
        if new_head == false then
            return false
        elseif new_head ~= true then
            head = new_head
            changed = true
        end
    end
    return not changed or head
end
--
-- Create \"virtual" callbacks `pre/post_mlist_to_hlist_filter` by setting
-- `mlist_to_hlist` callback. The default behaviour of `mlist_to_hlist` is kept by
-- using a default function, but it can still be overriden by using
-- `add_to_callback`.
default_functions["mlist_to_hlist"] = node.mlist_to_hlist
callback.create_callback("pre_mlist_to_hlist_filter", "list")
callback.create_callback("post_mlist_to_hlist_filter", "reverselist")
callback_register("mlist_to_hlist", function(head, ...)
    -- pre_mlist_to_hlist_filter
    local new_head = callback.call_callback("pre_mlist_to_hlist_filter", head, ...)
    if new_head == false then
        node.flush_list(head)
        return nil
    elseif new_head ~= true then
        head = new_head
    end

    -- mlist_to_hlist means either added functions or standard luatex behavior
    -- of node.mlist_to_hlist (handled by default function)
    head = callback.call_callback("mlist_to_hlist", head, ...)

    -- post_mlist_to_hlist_filter
    new_head = callback.call_callback("post_mlist_to_hlist_filter", head, ...)
    if new_head == false then
        node.flush_list(head)
        return nil
    elseif new_head ~= true then
        head = new_head
    end
    return head
end)
--
-- Compatibility with \LaTeX/ through luatexbase namespace. Needed for
-- luaotfload.
luatexbase = {
    registernumber = registernumber,
    attributes = attributes,
    new_attribute = alloc.new_attribute,
    callback_descriptions = callback.callback_descriptions,
    create_callback = callback.create_callback,
    add_to_callback = callback.add_to_callback,
    remove_from_callback = callback.remove_from_callback,
    call_callback = callback.call_callback,
    callbacktypes = {}
}