1: \ data structures (like C structs)
2:
3: \ Copyright (C) 1995 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., 675 Mass Ave, Cambridge, MA 02139, USA.
20:
21:
22: \ Usage example:
23: \
24: \ struct
25: \ 1 cells: field search-method
26: \ 1 cells: field reveal-method
27: \ end-struct wordlist-map
28: \
29: \ The structure can then be extended in the following way
30: \ wordlist-map
31: \ 1 cells: field enum-method
32: \ end-struct ext-wordlist-map \ with the fields search-method,...,enum-method
33:
34: : nalign ( addr1 n -- addr2 )
35: \ addr2 is the aligned version of addr1 wrt the alignment size n
36: 1- tuck + swap invert and ;
37:
38: : field ( offset1 align1 size align -- offset2 align2 )
39: \ note: this version uses local variables
40: Header reveal dofield: cfa,
41: >r rot r@ nalign dup , ( align1 size offset )
42: + swap r> nalign ;
43:
44: : end-struct ( size align -- )
45: 2constant ;
46:
47: 0 1 chars end-struct struct
48:
49: \ : field ( offset1 align1 size align -- offset2 align2 )
50: \ create-field
51: \ does> ( addr1 -- addr2 )
52: \ @ + ;
53:
54: \ I don't really like the "type:" syntax. Any other ideas? - anton
55: \ Also, this seems to be somewhat general. It probably belongs to some
56: \ other place
57: : cells: ( n -- size align )
58: cells cell ;
59:
60: : doubles: ( n -- size align )
61: 2* cells cell ;
62:
63: : chars: ( n -- size align )
64: chars 1 chars ;
65:
66: : floats: ( n -- size align )
67: floats 1 floats ;
68:
69: : dfloats: ( n -- size align )
70: dfloats 1 dfloats ;
71:
72: : sfloats: ( n -- size align )
73: sfloats 1 sfloats ;
74:
75: : struct-align ( size align -- )
76: dp @ swap nalign dp !
77: drop ;
78:
79: : struct-allot ( size align -- addr )
80: over swap struct-align
81: here swap allot ;
82:
83: : struct-allocate ( size align -- addr ior )
84: drop allocate ;
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