Annotation of gforth/compat/struct.fs, revision 1.2
1.1 anton 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:
1.2 ! anton 34: \ This is an ANS Forth program with an environmental dependency on
! 35: \ alignments that are powers of 2 (rewrite nalign for other systems)
! 36: \ and with an environmental dependence on case insensitivity (convert
! 37: \ everything to upper case for state sensitive systems).
! 38:
! 39: \ The program uses the following words
! 40: \ !!
! 41:
1.1 anton 42: : nalign ( addr1 n -- addr2 )
43: \ addr2 is the aligned version of addr1 wrt the alignment size n
44: 1- tuck + swap invert and ;
45:
1.2 ! anton 46: : dofield ( -- )
! 47: does> ( name execution: addr1 -- addr2 )
! 48: @ + ;
! 49:
! 50: : dozerofield ( -- )
! 51: immediate
! 52: does> ( name execution: -- )
! 53: drop ;
! 54:
! 55: : create-field ( offset1 align1 size align "name" -- offset2 align2 )
1.1 anton 56: create
1.2 ! anton 57: >r rot r@ nalign dup , ( align1 size offset R: align )
! 58: + swap r> nalign ;
! 59:
! 60: : field ( offset1 align1 size align "name" -- offset2 align2 )
! 61: \ name execution: addr1 -- addr2
! 62: 3 pick >r \ this uglyness is just for optimizing with dozerofield
! 63: create-field
! 64: r>
! 65: dup if
! 66: dofield
! 67: else
! 68: dozerofield
! 69: then ;
1.1 anton 70:
71: : end-struct ( size align -- )
1.2 ! anton 72: tuck nalign swap \ pad size to full alignment
! 73: 2constant ;
1.1 anton 74:
75: 0 1 chars end-struct struct
76:
77: \ I don't really like the "type:" syntax. Any other ideas? - anton
78: \ Also, this seems to be somewhat general. It probably belongs to some
79: \ other place
80: : cells: ( n -- size align )
1.2 ! anton 81: cells 1 aligned ;
1.1 anton 82:
83: : doubles: ( n -- size align )
1.2 ! anton 84: 2* cells 1 aligned ;
1.1 anton 85:
86: : chars: ( n -- size align )
87: chars 1 chars ;
88:
89: : floats: ( n -- size align )
1.2 ! anton 90: floats 1 faligned ;
1.1 anton 91:
92: : dfloats: ( n -- size align )
1.2 ! anton 93: dfloats 1 dfaligned ;
1.1 anton 94:
95: : sfloats: ( n -- size align )
1.2 ! anton 96: sfloats 1 sfaligned ;
1.1 anton 97:
98: : struct-align ( size align -- )
99: here swap nalign here - allot
100: drop ;
101:
102: : struct-allot ( size align -- addr )
103: over swap struct-align
104: here swap allot ;
105:
106: : struct-allocate ( size align -- addr ior )
107: drop allocate ;
1.2 ! anton 108:
! 109: : struct-alloc ( size align -- addr )
! 110: struct-allocate throw ;
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