summaryrefslogtreecommitdiff
path: root/Master/texmf-dist/tex/latex/polyglossia/polyglossia-brpt.lua
blob: 56af011152a4f165cfe6b39b15df82bd89fe56a1 (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
require('polyglossia') -- just in case...

local add_to_callback = luatexbase.add_to_callback
local remove_from_callback = luatexbase.remove_from_callback
local priority_in_callback = luatexbase.priority_in_callback

local get_quad = luaotfload.aux.get_quad -- needs luaotfload > 20130516

local next, type = next, type

local nodes, fonts, node = nodes, fonts, node

local nodecodes          = nodes.nodecodes

local insert_node_before = node.insert_before
local insert_node_after  = node.insert_after
local remove_node        = nodes.remove
local has_attribute      = node.has_attribute
local node_copy          = node.copy
local new_node           = node.new

local end_of_math        = node.end_of_math
if not end_of_math then -- luatex < .76
  local traverse_nodes = node.traverse_id
  local math_code      = nodecodes.math
  local end_of_math = function (n)
    for n in traverse_nodes(math_code, n.next) do
      return n
    end
  end
end

-- node types according to node.types()
local glue_code         = nodecodes.glue
local glue_spec_code    = nodecodes.glue_spec
local glyph_code        = nodecodes.glyph
local penalty_code      = nodecodes.penalty
local kern_code         = nodecodes.kern

-- we make a new node, so that we can copy it later on
local penalty_node   = new_node(penalty_code)
penalty_node.penalty = 10000

local function get_penalty_node()
  return node_copy(penalty_node)
end

-- same for glue node
local kern_node       = new_node(kern_code)

local function get_kern_node(dim)
  local n = node_copy(kern_node)
  n.kern = dim
  return n
end

-- we have here all possible space characters, referenced by their
-- unicode slot number, taken from char-def.lua
local space_chars = {[32]=1, [160]=1, [5760]=1, [6158]=1, [8192]=1, [8193]=1, [8194]=1, [8195]=1, 
  [8196]=1, [8197]=1, [8198]=1, [8199]=1, [8200]=1, [8201]=1, [8202]=1, [8239]=1, [8287]=1, [12288]=1}

-- from nodes-tst.lua, adapted
local function somespace(n,all)
    if n then
        local id = n.id
        if id == glue_code then
            return (all or (n.spec.width ~= 0)) and glue_code
        elseif id == kern_code then
            return (all or (n.kern ~= 0)) and kern_code
        elseif id == glyph_code then
            if space_chars[n.char] then
                return true
            else
                return false
            end
        end
    end
    return false
end

-- idem
local function somepenalty(n,value)
    if n then
        local id = n.id
        if id == penalty_code then
            if value then
                return n.penalty == value
            else
                return true
            end
        end
    end
    return false
end

local xpgfrptattr = luatexbase.attributes['xpg@frpt']

local left=1
local right=2
local byte = unicode.utf8.byte

-- Now there is a good question: how do we now, in lua, what a \thinspace is?
-- In the LaTeX source (ltspace.dtx) it is defined as:
-- \def\thinspace{\kern .16667em }. I see no way of seeing if it has been
-- overriden or not... So we stick to this value.
local thinspace  = 0.16667 
-- thickspace is defined in amsmath.sty as:
-- \renewcommand{\;}{\mspace+\thickmuskip{.2777em}}. Same problem as above, we
-- stick to this fixed value.
local thickspace = 0.2777 -- 5/18

local mappings =  {
 [byte(':')] = {left,  thickspace}, --really?
 [byte('!')] = {left,  thinspace},
 [byte('?')] = {left,  thinspace},
 [byte(';')] = {left,  thinspace},
 [byte('‼')] = {left,  thinspace},
 [byte('⁇')] = {left,  thinspace},
 [byte('⁈')] = {left,  thinspace},
 [byte('⁉')] = {left,  thinspace},
 [byte('»')] = {left,  thinspace},
 [byte('>')] = {left,  thinspace},
 [byte('«')] = {right, thinspace}, 
 [byte('‹')] = {right, thinspace}, 
 }

local function set_spacings(thinsp, thicksp)
  for _, m in pairs(mappings) do
    if m[2] == thinspace then
      m[2] = thinsp
    elseif m[2] == thickspace then
      m[2] = thicksp
    end
  end
  thickspace = thicksp
  thinspace = thinsp
end

-- from typo-spa.lua
local function process(head)
    local done = false
    local start = head
    -- head is always begin of par (whatsit), so we have at least two prev nodes
    -- penalty followed by glue
    while start do
        local id = start.id
        if id == glyph_code then
            local attr = has_attribute(start, xpgfrptattr)
            if attr and attr > 0 then
                local char = start.char
                local map = mappings[char]
                --node.unset_attribute(start, xpgfrptattr) -- needed?
                if map then
                    local quad = get_quad(start.font) -- might be optimized
                    local prev = start.prev
                    if map[1] == left and prev then
                        local prevprev = prev.prev
                        local somespace = somespace(prev,true)
                        -- TODO: there is a question here: do we override a preceding space or not?...
                        if somespace then
                            local somepenalty = somepenalty(prevprev,10000)
                            if somepenalty then
                                head = remove_node(head,prev,true)
                                head = remove_node(head,prevprev,true)
                            else
                                head = remove_node(head,prev,true)
                            end
                        end
                        insert_node_before(head,start,get_penalty_node())
                        insert_node_before(head,start,get_kern_node(map[2]*quad))
                        done = true
                    end
                    local next = start.next
                    if map[1] == right and next then
                        local nextnext = next.next
                        local somepenalty = somepenalty(next,10000)
                        if somepenalty then
                            local somespace = somespace(nextnext,true)
                            if somespace then
                                head = remove_node(head,next,true)
                                head = remove_node(head,nextnext,true)
                            end
                        else
                            local somespace = somespace(next,true)
                            if somespace then
                                head = remove_node(head,next,true)
                            end
                        end
                        insert_node_after(head,start,get_kern_node(map[2]*quad))
                        insert_node_after(head,start,get_penalty_node())
                        done = true
                    end
                end
            end
        elseif id == math_code then
            -- warning: this is a feature of luatex > 0.76
            start = end_of_math(start) -- weird, can return nil .. no math end?
        end
        if start then
            start = start.next
        end
    end
    return head, done
end

local callback_name = "pre_linebreak_filter"

local function activate()
  if not priority_in_callback (callback_name, "polyglossia-frpt.process") then
    add_to_callback(callback_name, process, "polyglossia-frpt.process", 1)
  end
end

local function desactivate()
  if priority_in_callback (callback_name, "polyglossia-frpt.process") then
    remove_from_callback(callback_name, "polyglossia-frpt.process")
  end
end

polyglossia.activate_frpt    = activate
polyglossia.desactivate_frpt = desactivate
polyglossia.set_spacings     = set_spacings
polyglossia.thinspace        = thinspace
polyglossia.thickspace       = thickpace