Diff for /gforth/struct.fs between versions 1.3 and 1.16

version 1.3, 1995/02/23 20:17:25 version 1.16, 2000/08/22 18:15:38
Line 1 Line 1
 \ $Id$  \ data structures (like C structs)
   
 \ Usage example:  \ Copyright (C) 1995, 1997 Free Software Foundation, Inc.
 \  
 \ struct  
 \     1 cells: field search-method  
 \     1 cells: field reveal-method  
 \ end-struct wordlist-map  
 \  
 \ The structure can then be extended in the following way  
 \ wordlist-map  
 \     1 cells: field enum-method  
 \ end-struct ext-wordlist-map \ with the fields search-method,...,enum-method  
   
 : nalign ( addr1 n -- addr2 )  \ This file is part of Gforth.
 \ addr2 is the aligned version of addr1 wrt the alignment size n  
   \ Gforth is free software; you can redistribute it and/or
   \ modify it under the terms of the GNU General Public License
   \ as published by the Free Software Foundation; either version 2
   \ of the License, or (at your option) any later version.
   
   \ This program is distributed in the hope that it will be useful,
   \ but WITHOUT ANY WARRANTY; without even the implied warranty of
   \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   \ GNU General Public License for more details.
   
   \ You should have received a copy of the GNU General Public License
   \ along with this program; if not, write to the Free Software
   \ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   
   : naligned ( addr1 n -- addr2 ) \ gforth
   \g @var{addr2} is the aligned version of @var{addr1} with respect to the
   \g alignment @var{n}.
  1- tuck +  swap invert and ;   1- tuck +  swap invert and ;
   
 : field ( offset1 align1 size align -- offset2 align2 )  ' naligned alias nalign \ old name, obsolete
 \ note: this version uses local variables  
      Header reveal -7 ( [ :dostruc ] Literal ) cfa,  
         >r rot r@ nalign  dup ,  ( align1 size offset )  
         + swap r> nalign ;  
   
 : end-struct ( size align -- )  
  2constant ;  
   
 0 1 chars end-struct struct  
   
 \ : field  ( offset1 align1 size align -- offset2 align2 )  
 \    create-field  
 \    does> ( addr1 -- addr2 )  
 \       @ + ;  
   
 \ I don't really like the "type:" syntax. Any other ideas? - anton  
 \ Also, this seems to be somewhat general. It probably belongs to some  
 \ other place  
 : cells: ( n -- size align )  
     cells cell ;  
   
 : doubles: ( n -- size align )  
     2* cells cell ;  
   
 : chars: ( n -- size align )  
     chars 1 chars ;  
   
 : floats: ( n -- size align )  
     floats 1 floats ;  
   
 \ dfoats and sfloats is not yet defined  
 \ : dfloats: ( n -- size align )  
 \     dfloats 1 dfloats ;  
 \   
 \ : sfloats: ( n -- size align )  
 \     sfloats 1 sfloats ;  
   
 : struct-align ( size align -- )  : dozerofield ( -- )
     dp @ swap nalign dp !      \ a field that makes no change
       \ to enable accessing the offset with "['] <field> >body @" this
       \ is not implemented with "['] noop alias"
       last @
       if
           immediate
       then
   does> ( name execution: -- )
     drop ;      drop ;
   
 : struct-allot ( size align -- addr )  : field, ( align1 offset1 align size --  align2 offset2 )
     over swap struct-align      swap rot over nalign dup , ( align1 size align offset )
       rot + >r nalign r> ;
   
   : create-field ( align1 offset1 align size --  align2 offset2 )
       create field, ;
   
   : field ( align1 offset1 align size "name" --  align2 offset2 ) \ gforth
       \g Create a field @var{name} with offset @var{offset1}, and the type
       \g given by @var{align size}. @var{offset2} is the offset of the
       \g next field, and @var{align2} is the alignment of all fields.@*
       \g @code{name} execution: @var{addr1} -- @var{addr2}.@*
       \g @var{addr2}=@var{addr1}+@var{offset1}
       2 pick 
       if \ field offset <> 0
           [IFDEF]  (Field)
               (Field)
           [ELSE]
               Header reveal dofield: cfa,
           [THEN]
       else
           create dozerofield
       then
       field, ;
   
   : end-struct ( align size "name" -- ) \ gforth
   \g Define a structure/type descriptor @var{name} with alignment
   \g @var{align} and size @var{size1} (@var{size} rounded up to be a
   \g multiple of @var{align}).@*
   \g @code{name} execution: -- @var{align size1}@*
       over nalign \ pad size to full alignment
       2constant ;
   
   1 chars 0 end-struct struct ( -- align size ) \ gforth
   \g An empty structure, used to start a structure definition.
   
   \ type descriptors
   1 aligned   1 cells   2constant cell% ( -- align size ) \ gforth
   1 chars     1 chars   2constant char% ( -- align size ) \ gforth
   1 faligned  1 floats  2constant float% ( -- align size ) \ gforth
   1 dfaligned 1 dfloats 2constant dfloat% ( -- align size ) \ gforth
   1 sfaligned 1 sfloats 2constant sfloat% ( -- align size ) \ gforth
   cell% 2*              2constant double% ( -- align size ) \ gforth
   
   \ memory allocation words
   ' drop alias %alignment ( align size -- align ) \ gforth
   \g The alignment of the structure.
   ' nip alias %size ( align size -- size ) \ gforth
   \g The size of the structure.
   
   : %align ( align size -- ) \ gforth
       \G Align the data space pointer to the alignment @var{align}. 
       drop here swap nalign here - allot ;
   
   : %allot ( align size -- addr ) \ gforth
       \g Allot @var{size} address units of data space with alignment
       \g @var{align}; the resulting block of data is found at
       \g @var{addr}.
       tuck %align
     here swap allot ;      here swap allot ;
   
 : struct-allocate ( size align -- addr )  : %allocate ( align size -- addr ior ) \ gforth
     drop allocate ;      \g Allocate @var{size} address units with alignment @var{align},
       \g similar to @code{allocate}.
       nip allocate ;
   
   : %alloc ( size align -- addr ) \ gforth
       \g Allocate @var{size} address units with alignment @var{align},
       \g giving a data block at @var{addr}; @code{throw} an ior code
       \g if not successful.
       %allocate throw ;

Removed from v.1.3  
changed lines
  Added in v.1.16


FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>