[gforth] / gforth / utf-8.fs  

gforth: gforth/utf-8.fs

1 : pazsan 1.1 \ UTF-8 handling 12dec04py
2 :    
3 :     \ Copyright (C) 2004 Free Software Foundation, Inc.
4 :    
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 :     BEGIN 2dup u>= WHILE 5 lshift r> 1+ >r REPEAT
31 :     2drop r> ;
32 :    
33 :     : u8@+ ( u8addr -- u8addr' u )
34 : anton 1.13 count dup max-single-byte u< ?EXIT \ special case ASCII
35 : pazsan 1.1 $7F and $40 >r
36 :     BEGIN dup r@ and WHILE r@ xor
37 :     6 lshift r> 5 lshift >r >r count
38 : pazsan 1.7 dup $C0 and $80 <> IF UTF-8-err throw THEN
39 : pazsan 1.1 $3F and r> or
40 :     REPEAT rdrop ;
41 :    
42 :     : u8!+ ( u u8addr -- u8addr' )
43 : anton 1.13 over max-single-byte u< IF tuck c! 1+ EXIT THEN \ special case ASCII
44 : pazsan 1.1 >r 0 swap $3F
45 :     BEGIN 2dup u> WHILE
46 :     2/ >r dup $3F and $80 or swap 6 rshift r>
47 :     REPEAT $7F xor 2* or r>
48 :     BEGIN over $80 u>= WHILE tuck c! 1+ REPEAT nip ;
49 :    
50 : pazsan 1.8 \ plug-in so that char and '<char> work for UTF-8
51 :    
52 : anton 1.9 [ifundef] char@ \ !! bootstrapping help
53 :     Defer char@ ( addr u -- char addr' u' )
54 :     :noname over c@ -rot 1 /string ; IS char@
55 :     [then]
56 :    
57 : pazsan 1.8 :noname ( addr u -- char addr' u' )
58 : anton 1.9 \ !! the if here seems to work around some breakage, but not
59 :     \ entirely; e.g., try 'ç' with LANG=C.
60 :     dup 1 u<= IF defers char@ EXIT THEN
61 : pazsan 1.8 over + >r u8@+ swap r> over - ; IS char@
62 :    
63 : pazsan 1.1 \ scan to next/previous character
64 :    
65 : anton 1.13 \ alternative names: u8char+ u8char-
66 :    
67 : pazsan 1.12 : u8>> ( u8addr -- u8addr' ) u8@+ drop ;
68 : pazsan 1.1 : u8<< ( u8addr -- u8addr' )
69 : anton 1.13 BEGIN 1- dup c@ $C0 and max-single-byte <> UNTIL ;
70 : pazsan 1.1
71 :     \ utf key and emit
72 :    
73 :     : u8key ( -- u )
74 : anton 1.13 defers key dup max-single-byte u< ?EXIT \ special case ASCII
75 : pazsan 1.1 $7F and $40 >r
76 :     BEGIN dup r@ and WHILE r@ xor
77 :     6 lshift r> 5 lshift >r >r defers key
78 : pazsan 1.7 dup $C0 and $80 <> IF UTF-8-err throw THEN
79 : pazsan 1.1 $3F and r> or
80 :     REPEAT rdrop ;
81 :    
82 :     : u8emit ( u -- )
83 : anton 1.13 dup max-single-byte u< IF defers emit EXIT THEN \ special case ASCII
84 : pazsan 1.1 0 swap $3F
85 :     BEGIN 2dup u> WHILE
86 :     2/ >r dup $3F and $80 or swap 6 rshift r>
87 :     REPEAT $7F xor 2* or
88 :     BEGIN dup $80 u>= WHILE defers emit REPEAT drop ;
89 : anton 1.13
90 :     \ utf-8 stuff for xchars
91 :    
92 :     : +u8/string ( c-addr1 u1 -- c-addr2 u2 )
93 :     over dup u8>> swap - /string ;
94 :    
95 :     : -u8/string ( c-addr1 u1 -- c-addr2 u2 )
96 :     over dup u8<< swap - /string ;
97 :    
98 :     : u8@ ( c-addr -- u )
99 :     u8@+ nip ;
100 :    
101 :     : u8!+? ( xc xc-addr1 u1 -- xc-addr2 u2 f )
102 :     >r over u8len r@ over u< if ( xc xc-addr1 len r: u1 )
103 :     \ not enough space
104 :     drop nip r> false
105 :     else
106 :     >r u8!+ r> r> swap - true
107 :     then ;
108 :    
109 :     : u8addrlen ( u8-addr -- u )
110 :     \ length of UTF-8 char starting at u8-addr (accesses only u8-addr)
111 :     c@
112 :     dup $80 u< if drop 1 exit endif
113 :     dup $c0 u< if UTF-8-err throw endif
114 :     dup $e0 u< if drop 2 exit endif
115 :     dup $f0 u< if drop 3 exit endif
116 :     dup $f8 u< if drop 4 exit endif
117 :     dup $fc u< if drop 5 exit endif
118 :     dup $fe u< if drop 6 exit endif
119 :     UTF-8-err throw ;
120 :    
121 :     : -u8trailing-garbage ( addr u1 -- addr u2 )
122 :     2dup + dup u8<< ( addr u1 end1 end2 )
123 :     2dup dup u8addrlen + = if \ last character ok
124 :     2drop
125 :     else
126 :     nip nip over -
127 :     then ;
128 :    
129 :     : set-encoding-utf-8 ( -- )
130 :     ['] u8emit is xemit
131 :     ['] u8key is xkey
132 :     ['] u8>> is xchar+
133 :     ['] u8<< is xchar-
134 :     ['] +u8/string is +x/string
135 :     ['] -u8/string is -x/string
136 :     ['] u8@ is xc@
137 :     ['] u8!+? is xc!+?
138 :     ['] u8@+ is xc@+
139 :     ['] u8len is xc-size
140 :     ['] -u8trailing-garbage is -trailing-garbage
141 :     ;
142 : pazsan 1.1
143 : anton 1.15 : utf-8-cold ( -- )
144 :     s" LANG" getenv s" .UTF-8" search nip nip
145 :     IF set-encoding-utf-8 ELSE set-encoding-fixed-width THEN ;
146 :    
147 :     ' utf-8-cold INIT8 chained
148 :    
149 :     utf-8-cold
CVS Admin

Powered by ViewCVS 1.0-dev 		(Powered by ViewCVS)

ViewCVS and CVS Help