Source Browser ?

1
if
 
not
 
modules
 
then
 
modules
 
=
 
{
 
}
 
end
 
modules
 
[
'
font-imp-ligatures
'
]
 
=
 
{
2    
version
   
=
 
1
.
001
,
3    
comment
   
=
 
"
companion to font-ini.mkiv
"
,
4    
author
    
=
 
"
Hans Hagen, PRAGMA-ADE, Hasselt NL
"
,
5    
copyright
 
=
 
"
PRAGMA ADE / ConTeXt Development Team
"
,
6    
license
   
=
 
"
see context related readme files
"
7
}
8
9
local
 
lpegmatch
 
=
 
lpeg
.
match
10
local
 
utfsplit
 
=
 
utf
.
split
11
local
 
settings_to_array
 
=
 
utilities
.
parsers
.
settings_to_array
12
13
local
 
fonts
              
=
 
fonts
14
local
 
otf
                
=
 
fonts
.
handlers
.
otf
15
local
 
registerotffeature
 
=
 
otf
.
features
.
register
16
local
 
addotffeature
      
=
 
otf
.
addfeature
17
18
-- This is a quick and dirty hack.
19
20
local
 
lookups
 
=
 
{
 
}
21
local
 
protect
 
=
 
{
 
}
22
local
 
revert
  
=
 
{
 
}
23
local
 
zwjchar
 
=
 
0x200C
24
local
 
zwj
     
=
 
{
 
zwjchar
 
}
25
26
addotffeature
 
{
27    
name
    
=
 
"
blockligatures
"
,
28    
type
    
=
 
"
chainsubstitution
"
,
29    
nocheck
 
=
 
true
,
 
-- because there is no 0x200C in the font
30    
prepend
 
=
 
true
,
 
-- make sure we do it early
31    
future
  
=
 
true
,
 
-- avoid nilling due to no steps yet
32    
lookups
 
=
 
{
33        
{
34            
type
 
=
 
"
multiple
"
,
35            
data
 
=
 
lookups
,
36        
}
,
37    
}
,
38    
data
 
=
 
{
39        
rules
 
=
 
protect
,
40    
}
41
}
42
43
addotffeature
 
{
44    
name
     
=
 
"
blockligatures
"
,
45    
type
     
=
 
"
chainsubstitution
"
,
46    
nocheck
  
=
 
true
,
  
-- because there is no 0x200C in the font
47    
append
   
=
 
true
,
  
-- this is done late
48    
overload
 
=
 
false
,
 
-- we don't want to overload the previous definition
49    
lookups
  
=
 
{
50        
{
51            
type
 
=
 
"
ligature
"
,
52            
data
 
=
 
lookups
,
53        
}
,
54    
}
,
55    
data
 
=
 
{
56        
rules
 
=
 
revert
,
57    
}
58
}
59
60
registerotffeature
 
{
61    
name
        
=
 
'
blockligatures
'
,
62    
description
 
=
 
'
block certain ligatures
'
,
63
}
64
65
local
 
splitter
 
=
 
lpeg
.
splitat
(
"
:
"
)
66
67
local
 
function
 
blockligatures
(
str
)
68
69    
local
 
t
 
=
 
settings_to_array
(
str
)
70
71    
for
 
i
=
1
,
#
t
 
do
72        
local
 
ti
 
=
 
t
[
i
]
73        
local
 
before
,
 
current
,
 
after
 
=
 
lpegmatch
(
splitter
,
ti
)
74        
if
 
current
 
and
 
after
 
then
 
-- before is returned when no match
75            
-- experimental joke
76            
if
 
before
 
then
77                
before
 
=
 
utfsplit
(
before
)
78                
for
 
i
=
1
,
#
before
 
do
79                    
before
[
i
]
 
=
 
{
 
before
[
i
]
 
}
80                
end
81            
end
82            
if
 
current
 
then
83                
current
 
=
 
utfsplit
(
current
)
84            
end
85            
if
 
after
 
then
86                
after
 
=
 
utfsplit
(
after
)
87                
for
 
i
=
1
,
#
after
 
do
88                    
after
[
i
]
 
=
 
{
 
after
[
i
]
 
}
89                
end
90            
end
91        
else
92            
before
  
=
 
nil
93            
current
 
=
 
utfsplit
(
ti
)
94            
after
   
=
 
nil
95        
end
96        
if
 
#
current
 
>
 
1
 
then
97            
local
 
one
 
=
 
current
[
1
]
98            
local
 
two
 
=
 
current
[
2
]
99            
lookups
[
one
]
 
=
 
{
 
one
,
 
zwjchar
 
}
100            
local
 
one
 
=
 
{
 
one
 
}
101            
local
 
two
 
=
 
{
 
two
 
}
102            
local
 
new
 
=
 
#
protect
 
+
 
1
103            
protect
[
new
]
 
=
 
{
104                
before
  
=
 
before
,
105                
current
 
=
 
{
 
one
,
 
two
 
}
,
106                
after
   
=
 
after
,
107                
lookups
 
=
 
{
 
1
 
}
,
 
-- not shared !
108            
}
109            
revert
[
new
]
 
=
 
{
110             
-- before = before,
111                
current
 
=
 
{
 
one
,
 
zwj
 
}
,
112             
-- after   = { two, unpack(after) },
113                
after
   
=
 
{
 
two
 
}
,
114                
lookups
 
=
 
{
 
1
 
}
,
 
-- not shared !
115            
}
116        
end
117    
end
118
end
119
120
-- blockligatures("\0\0")
121
122
otf
.
helpers
.
blockligatures
 
=
 
blockligatures
123
124
-- blockligatures("fi,ff")
125
-- blockligatures("fl")
126
-- blockligatures("u:fl:age")
127
128
if
 
context
 
then
129
130    
interfaces
.
implement
 
{
131        
name
      
=
 
"
blockligatures
"
,
132        
arguments
 
=
 
"
string
"
,
133        
actions
   
=
 
blockligatures
,
134    
}
135
136
end
137