[gforth] / gforth / utf-8.fs  

gforth: gforth/utf-8.fs


1 : pazsan 1.1 \ UTF-8 handling 12dec04py
2 :    
3 : anton 1.18 \ Copyright (C) 2004,2005 Free Software Foundation, Inc.
4 : pazsan 1.1
5 :     \ This file is part of Gforth.
6 :    
7 :     \ Gforth is free software; you can redistribute it and/or
8 :     \ modify it under the terms of the GNU General Public License
9 :     \ as published by the Free Software Foundation; either version 2
10 :     \ of the License, or (at your option) any later version.
11 :    
12 :     \ This program is distributed in the hope that it will be useful,
13 :     \ but WITHOUT ANY WARRANTY; without even the implied warranty of
14 :     \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 :     \ GNU General Public License for more details.
16 :    
17 :     \ You should have received a copy of the GNU General Public License
18 :     \ along with this program; if not, write to the Free Software
19 :     \ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
20 :    
21 :     \ short: u8 means utf-8 encoded address
22 :    
23 : pazsan 1.7 s" malformed UTF-8 character" exception Constant UTF-8-err
24 :    
25 : anton 1.13 $80 Value max-single-byte
26 : pazsan 1.10
27 : pazsan 1.4 : u8len ( u8 -- n )
28 : anton 1.13 dup max-single-byte u< IF drop 1 EXIT THEN \ special case ASCII
29 : pazsan 1.1 $800 2 >r
30 : pazsan 1.17 BEGIN 2dup u>= WHILE 5 lshift r> 1+ >r dup 0= UNTIL THEN
31 : pazsan 1.1 2drop r> ;
32 :    
33 :     : u8@+ ( u8addr -- u8addr' u )
34 : anton 1.13 count dup max-single-byte u< ?EXIT \ special case ASCII
35 : pazsan 1.17 dup $C2 u< IF UTF-8-err throw THEN \ malformed character
36 : pazsan 1.1 $7F and $40 >r
37 :     BEGIN dup r@ and WHILE r@ xor
38 :     6 lshift r> 5 lshift >r >r count
39 : pazsan 1.7 dup $C0 and $80 <> IF UTF-8-err throw THEN
40 : pazsan 1.1 $3F and r> or
41 :     REPEAT rdrop ;
42 :    
43 :     : u8!+ ( u u8addr -- u8addr' )
44 : anton 1.13 over max-single-byte u< IF tuck c! 1+ EXIT THEN \ special case ASCII
45 : pazsan 1.1 >r 0 swap $3F
46 :     BEGIN 2dup u> WHILE
47 :     2/ >r dup $3F and $80 or swap 6 rshift r>
48 :     REPEAT $7F xor 2* or r>
49 :     BEGIN over $80 u>= WHILE tuck c! 1+ REPEAT nip ;
50 :    
51 : pazsan 1.8 \ plug-in so that char and '<char> work for UTF-8
52 :    
53 : anton 1.9 [ifundef] char@ \ !! bootstrapping help
54 :     Defer char@ ( addr u -- char addr' u' )
55 :     :noname over c@ -rot 1 /string ; IS char@
56 :     [then]
57 :    
58 : pazsan 1.8 :noname ( addr u -- char addr' u' )
59 : anton 1.9 \ !! the if here seems to work around some breakage, but not
60 :     \ entirely; e.g., try 'ç' with LANG=C.
61 :     dup 1 u<= IF defers char@ EXIT THEN
62 : pazsan 1.8 over + >r u8@+ swap r> over - ; IS char@
63 :    
64 : pazsan 1.1 \ scan to next/previous character
65 :    
66 : anton 1.13 \ alternative names: u8char+ u8char-
67 :    
68 : pazsan 1.12 : u8>> ( u8addr -- u8addr' ) u8@+ drop ;
69 : pazsan 1.1 : u8<< ( u8addr -- u8addr' )
70 : anton 1.13 BEGIN 1- dup c@ $C0 and max-single-byte <> UNTIL ;
71 : pazsan 1.1
72 :     \ utf key and emit
73 :    
74 :     : u8key ( -- u )
75 : anton 1.13 defers key dup max-single-byte u< ?EXIT \ special case ASCII
76 : pazsan 1.17 dup $C2 u< IF UTF-8-err throw THEN \ malformed character
77 : pazsan 1.1 $7F and $40 >r
78 :     BEGIN dup r@ and WHILE r@ xor
79 :     6 lshift r> 5 lshift >r >r defers key
80 : pazsan 1.7 dup $C0 and $80 <> IF UTF-8-err throw THEN
81 : pazsan 1.1 $3F and r> or
82 :     REPEAT rdrop ;
83 :    
84 :     : u8emit ( u -- )
85 : anton 1.13 dup max-single-byte u< IF defers emit EXIT THEN \ special case ASCII
86 : pazsan 1.1 0 swap $3F
87 :     BEGIN 2dup u> WHILE
88 :     2/ >r dup $3F and $80 or swap 6 rshift r>
89 :     REPEAT $7F xor 2* or
90 :     BEGIN dup $80 u>= WHILE defers emit REPEAT drop ;
91 : anton 1.13
92 :     \ utf-8 stuff for xchars
93 :    
94 :     : +u8/string ( c-addr1 u1 -- c-addr2 u2 )
95 :     over dup u8>> swap - /string ;
96 :    
97 :     : -u8/string ( c-addr1 u1 -- c-addr2 u2 )
98 :     over dup u8<< swap - /string ;
99 :    
100 :     : u8@ ( c-addr -- u )
101 :     u8@+ nip ;
102 :    
103 :     : u8!+? ( xc xc-addr1 u1 -- xc-addr2 u2 f )
104 :     >r over u8len r@ over u< if ( xc xc-addr1 len r: u1 )
105 :     \ not enough space
106 :     drop nip r> false
107 :     else
108 :     >r u8!+ r> r> swap - true
109 :     then ;
110 :    
111 :     : u8addrlen ( u8-addr -- u )
112 :     \ length of UTF-8 char starting at u8-addr (accesses only u8-addr)
113 :     c@
114 :     dup $80 u< if drop 1 exit endif
115 :     dup $c0 u< if UTF-8-err throw endif
116 :     dup $e0 u< if drop 2 exit endif
117 :     dup $f0 u< if drop 3 exit endif
118 :     dup $f8 u< if drop 4 exit endif
119 :     dup $fc u< if drop 5 exit endif
120 :     dup $fe u< if drop 6 exit endif
121 :     UTF-8-err throw ;
122 :    
123 :     : -u8trailing-garbage ( addr u1 -- addr u2 )
124 :     2dup + dup u8<< ( addr u1 end1 end2 )
125 :     2dup dup u8addrlen + = if \ last character ok
126 :     2drop
127 :     else
128 :     nip nip over -
129 :     then ;
130 :    
131 : anton 1.22 [IFUNDEF] wcwidth
132 :     : wcwidth abort ;
133 :     [THEN]
134 :    
135 : pazsan 1.19 : u8width ( xcaddr u -- n )
136 :     0 rot rot over + swap ?DO
137 : anton 1.22 I xc@+ swap >r wcwidth +
138 : pazsan 1.19 r> I - +LOOP ;
139 :    
140 : anton 1.13 : set-encoding-utf-8 ( -- )
141 :     ['] u8emit is xemit
142 :     ['] u8key is xkey
143 :     ['] u8>> is xchar+
144 :     ['] u8<< is xchar-
145 :     ['] +u8/string is +x/string
146 :     ['] -u8/string is -x/string
147 :     ['] u8@ is xc@
148 :     ['] u8!+? is xc!+?
149 :     ['] u8@+ is xc@+
150 :     ['] u8len is xc-size
151 : pazsan 1.20 [ [IFDEF] x-width ]
152 : pazsan 1.19 ['] u8width is x-width
153 : pazsan 1.20 [ [THEN] ]
154 : anton 1.13 ['] -u8trailing-garbage is -trailing-garbage
155 :     ;
156 : pazsan 1.1
157 : anton 1.15 : utf-8-cold ( -- )
158 : pazsan 1.16 s" LC_ALL" getenv 2dup d0= IF 2drop
159 :     s" LC_CTYPE" getenv 2dup d0= IF 2drop
160 :     s" LANG" getenv 2dup d0= IF 2drop
161 :     s" C" THEN THEN THEN
162 :     s" UTF-8" search nip nip
163 : anton 1.15 IF set-encoding-utf-8 ELSE set-encoding-fixed-width THEN ;
164 :    
165 :     ' utf-8-cold INIT8 chained
166 :    
167 :     utf-8-cold

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