Annotation of gforth/kernel/xchars.fs, revision 1.10
1.1 anton 1: \ extended characters (either 8bit or UTF-8, possibly other encodings)
2: \ and their fixed-size variant
3:
1.5 anton 4: \ Copyright (C) 2005,2006 Free Software Foundation, Inc.
1.1 anton 5:
6: \ This file is part of Gforth.
7:
8: \ Gforth is free software; you can redistribute it and/or
9: \ modify it under the terms of the GNU General Public License
10: \ as published by the Free Software Foundation; either version 2
11: \ of the License, or (at your option) any later version.
12:
13: \ This program is distributed in the hope that it will be useful,
14: \ but WITHOUT ANY WARRANTY; without even the implied warranty of
15: \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16: \ GNU General Public License for more details.
17:
18: \ You should have received a copy of the GNU General Public License
19: \ along with this program; if not, write to the Free Software
20: \ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
21:
22: \ We can do some of these (and possibly faster) by just using the
23: \ utf-8 words with an appropriate setting of max-single-byte, but I
24: \ like to see how an 8bit setting without UTF-8 stuff looks like.
25:
1.9 pazsan 26: Defer xemit ( xc -- ) \ xchar-ext
27: \G Prints an xchar on the terminal.
28: Defer xkey ( -- xc ) \ xchar-ext
29: \G Reads an xchar from the terminal. This will discard all input
30: \G events up to the completion of the xchar.
31: Defer xchar+ ( xc-addr1 -- xc-addr2 ) \ xchar-ext
32: \G Adds the size of the xchar stored at @var{xc-addr1} to this address,
33: \G giving @var{xc-addr2}.
34: Defer xchar- ( xc-addr1 -- xc-addr2 ) \ xchar-ext
35: \G Goes backward from @var{xc_addr1} until it finds an xchar so that
36: \G the size of this xchar added to @var{xc_addr2} gives
37: \G @var{xc_addr1}.
38: Defer +x/string ( xc-addr1 u1 -- xc-addr2 u2 ) \ xchar plus-x-slash-string
39: \G Step forward by one xchar in the buffer defined by address
40: \G @var{xc-addr1}, size @var{u1} pchars. @var{xc-addr2} is the address
41: \G and u2 the size in pchars of the remaining buffer after stepping
42: \G over the first xchar in the buffer.
43: Defer x\string- ( xc-addr1 u1 -- xc-addr1 u2 ) \ xchar x-back-string-minus
44: \G Step backward by one xchar in the buffer defined by address
45: \G @var{xc-addr1} and size @var{u1} in pchars, starting at the end of
46: \G the buffer. @var{xc-addr1} is the address and @var{u2} the size in
47: \G pchars of the remaining buffer after stepping backward over the
48: \G last xchar in the buffer.
49: Defer xc@ ( xc-addr -- xc ) \ xchar-ext xc-fetch
50: \G Fetchs the xchar @var{xc} at @var{xc-addr1}.
51: Defer xc!+? ( xc xc-addr1 u1 -- xc-addr2 u2 f ) \ xchar-ext xc-store-plus-query
52: \G Stores the xchar @var{xc} into the buffer starting at address
53: \G @var{xc-addr1}, @var{u1} pchars large. @var{xc-addr2} points to the
54: \G first memory location after @var{xc}, @var{u2} is the remaining
55: \G size of the buffer. If the xchar @var{xc} did fit into the buffer,
56: \G @var{f} is true, otherwise @var{f} is false, and @var{xc-addr2}
57: \G @var{u2} equal @var{xc-addr1} @var{u1}. XC!+? is safe for buffer
58: \G overflows, and therefore preferred over XC!+.
59: Defer xc@+ ( xc-addr1 -- xc-addr2 xc ) \ xchar-ext xc-fetch-plus
60: \G Fetchs the xchar @var{xc} at @var{xc-addr1}. @var{xc-addr2} points
61: \G to the first memory location after @var{xc}.
62: Defer xc-size ( xc -- u ) \ xchar-ext
63: \G Computes the memory size of the xchar @var{xc} in pchars.
64: Defer x-size ( xc-addr u1 -- u2 ) \ xchar
65: \G Computes the memory size of the first xchar stored at @var{xc-addr}
66: \G in pchars.
67: Defer x-width ( xc-addr u -- n ) \ xchar-ext
68: \G @var{n} is the number of monospace ASCII pchars that take the same
69: \G space to display as the the xchar string starting at @var{xc-addr},
70: \G using @var{u} pchars; assuming a monospaced display font,
71: \G i.e. pchar width is always an integer multiple of the width of an
72: \G ASCII pchar.
73: Defer -trailing-garbage ( xc-addr u1 -- addr u2 ) \ xchar-ext
74: \G Examine the last XCHAR in the buffer @var{xc-addr} @var{u1}---if
75: \G the encoding is correct and it repesents a full pchar, @var{u2}
76: \G equals @var{u1}, otherwise, @var{u2} represents the string without
77: \G the last (garbled) xchar.
1.1 anton 78:
1.2 anton 79: \ derived words, faster implementations are probably possible
80:
1.6 pazsan 81: : x@+/string ( xc-addr1 u1 -- xc-addr2 u2 xc )
1.2 anton 82: \ !! check for errors?
1.8 pazsan 83: over >r +x/string
1.2 anton 84: r> xc@ ;
85:
1.10 ! pazsan 86: Create xholdbuf 8 allot
! 87: : xhold ( xc -- )
! 88: \G Put xc into the pictured numeric output
! 89: xholdbuf 8 xc!+? 2drop
! 90: BEGIN 1- dup xholdbuf u>= WHILE dup c@ hold REPEAT drop ;
! 91:
1.1 anton 92: \ fixed-size versions of these words
93:
94: : char- ( c-addr1 -- c-addr2 )
95: [ 1 chars ] literal - ;
96:
1.6 pazsan 97: : +string ( c-addr1 u1 -- c-addr2 u2 )
1.1 anton 98: 1 /string ;
1.6 pazsan 99: : string- ( c-addr1 u1 -- c-addr1 u2 )
100: 1- ;
1.1 anton 101:
102: : c!+? ( c c-addr1 u1 -- c-addr2 u2 f )
1.3 anton 103: dup 1 chars u< if \ or use < ?
104: rot drop false
105: else
1.1 anton 106: >r dup >r c!
1.3 anton 107: r> r> 1 /string true
1.1 anton 108: then ;
109:
110: : c-size ( c -- 1 )
111: drop 1 ;
112:
113: : set-encoding-fixed-width ( -- )
114: ['] emit is xemit
115: ['] key is xkey
116: ['] char+ is xchar+
117: ['] char- is xchar-
1.8 pazsan 118: ['] +string is +x/string
119: ['] string- is x\string-
1.1 anton 120: ['] c@ is xc@
121: ['] c!+? is xc!+?
122: ['] count is xc@+
123: ['] c-size is xc-size
1.7 pazsan 124: ['] c-size is x-size
1.4 pazsan 125: ['] nip IS x-width
1.1 anton 126: ['] noop is -trailing-garbage
127: ;
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