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Xchar changes after discussion at EuroForth 2007

    1: \ extended characters (either 8bit or UTF-8, possibly other encodings)
    2: \ and their fixed-size variant
    3: 
    4: \ Copyright (C) 2005,2006 Free Software Foundation, Inc.
    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: 
   26: DEFER XEMIT ( xc -- )
   27: DEFER XKEY ( -- xc )
   28: DEFER XCHAR+ ( xc-addr1 -- xc-addr2 )
   29: DEFER XCHAR- ( xc-addr1 -- xc-addr2 )
   30: DEFER +X/STRING ( xc-addr1 u1 -- xc-addr2 u2 )
   31: DEFER X\STRING- ( xc-addr1 u1 -- xc-addr1 u2 )
   32: DEFER XC@ ( xc-addr -- xc )
   33: DEFER XC!+? ( xc xc-addr1 u1 -- xc-addr2 u2 f ) \ f if operation succeeded
   34: DEFER XC@+ ( xc-addr1 -- xc-addr2 xc )
   35: DEFER XC-SIZE ( xc -- u ) \ size in cs
   36: DEFER X-SIZE ( xc-addr u1 -- u2 ) \ size in cs
   37: DEFER X-WIDTH ( addr u -- n ) \ size in fixed chars
   38: DEFER -TRAILING-GARBAGE ( addr u1 -- addr u2 ) \ remove trailing incomplete xc
   39: 
   40: \ derived words, faster implementations are probably possible
   41: 
   42: : x@+/string ( xc-addr1 u1 -- xc-addr2 u2 xc )
   43:     \ !! check for errors?
   44:     over >r +x/string
   45:     r> xc@ ;
   46: 
   47: \ fixed-size versions of these words
   48: 
   49: : char- ( c-addr1 -- c-addr2 )
   50:     [ 1 chars ] literal - ;
   51: 
   52: : +string ( c-addr1 u1 -- c-addr2 u2 )
   53:     1 /string ;
   54: : string- ( c-addr1 u1 -- c-addr1 u2 )
   55:     1- ;
   56: 
   57: : c!+? ( c c-addr1 u1 -- c-addr2 u2 f )
   58:     dup 1 chars u< if \ or use < ?
   59: 	rot drop false
   60:     else
   61: 	>r dup >r c!
   62: 	r> r> 1 /string true
   63:     then ;
   64: 
   65: : c-size ( c -- 1 )
   66:     drop 1 ;
   67: 
   68: : set-encoding-fixed-width ( -- )
   69:     ['] emit is xemit
   70:     ['] key is xkey
   71:     ['] char+ is xchar+
   72:     ['] char- is xchar-
   73:     ['] +string is +x/string
   74:     ['] string- is x\string-
   75:     ['] c@ is xc@
   76:     ['] c!+? is xc!+?
   77:     ['] count is xc@+
   78:     ['] c-size is xc-size
   79:     ['] c-size is x-size
   80:     ['] nip IS x-width
   81:     ['] noop is -trailing-garbage
   82: ;