version 1.6, 1995/09/06 21:00:30
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version 1.13, 1998/04/14 16:43:07
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\ $Id$ |
\ data structures (like C structs) |
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\ Usage example: |
\ Copyright (C) 1995, 1997 Free Software Foundation, Inc. |
\ |
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\ struct |
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\ 1 cells: field search-method |
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\ 1 cells: field reveal-method |
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\ end-struct wordlist-map |
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\ |
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\ The structure can then be extended in the following way |
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\ wordlist-map |
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\ 1 cells: field enum-method |
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\ end-struct ext-wordlist-map \ with the fields search-method,...,enum-method |
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: nalign ( addr1 n -- addr2 ) |
\ This file is part of Gforth. |
\ addr2 is the aligned version of addr1 wrt the alignment size n |
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1- tuck + swap invert and ; |
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: field ( offset1 align1 size align -- offset2 align2 ) |
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\ note: this version uses local variables |
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Header reveal -7 ( [ :dostruc ] Literal ) cfa, |
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>r rot r@ nalign dup , ( align1 size offset ) |
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+ swap r> nalign ; |
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: end-struct ( size align -- ) |
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2constant ; |
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0 1 chars end-struct struct |
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\ : field ( offset1 align1 size align -- offset2 align2 ) |
\ Gforth is free software; you can redistribute it and/or |
\ create-field |
\ modify it under the terms of the GNU General Public License |
\ does> ( addr1 -- addr2 ) |
\ as published by the Free Software Foundation; either version 2 |
\ @ + ; |
\ of the License, or (at your option) any later version. |
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\ I don't really like the "type:" syntax. Any other ideas? - anton |
\ This program is distributed in the hope that it will be useful, |
\ Also, this seems to be somewhat general. It probably belongs to some |
\ but WITHOUT ANY WARRANTY; without even the implied warranty of |
\ other place |
\ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
: cells: ( n -- size align ) |
\ GNU General Public License for more details. |
cells cell ; |
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: doubles: ( n -- size align ) |
\ You should have received a copy of the GNU General Public License |
2* cells cell ; |
\ along with this program; if not, write to the Free Software |
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\ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
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: chars: ( n -- size align ) |
: nalign ( addr1 n -- addr2 ) \ gforth |
chars 1 chars ; |
\g @code{addr2} is the aligned version of @code{addr1} wrt the |
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\g alignment @code{n}. |
: floats: ( n -- size align ) |
1- tuck + swap invert and ; |
floats 1 floats ; |
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: dfloats: ( n -- size align ) |
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dfloats 1 dfloats ; |
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: sfloats: ( n -- size align ) |
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sfloats 1 sfloats ; |
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: struct-align ( size align -- ) |
: dozerofield ( -- ) |
dp @ swap nalign dp ! |
\ a field that makes no change |
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\ to enable accessing the offset with "['] <field> >body @" this |
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\ is not implemented with "['] noop alias" |
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last @ |
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if |
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immediate |
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then |
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does> ( name execution: -- ) |
drop ; |
drop ; |
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: 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 ) |
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rot + >r nalign r> ; |
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: create-field ( align1 offset1 align size -- align2 offset2 ) |
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create field, ; |
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: field ( align1 offset1 align size "name" -- align2 offset2 ) \ gforth |
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\G name execution: ( addr1 -- addr2 ) |
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2 pick |
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if \ field offset <> 0 |
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[IFDEF] (Field) |
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(Field) |
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[ELSE] |
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Header reveal dofield: cfa, |
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[THEN] |
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else |
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create dozerofield |
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then |
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field, ; |
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: end-struct ( align size "name" -- ) \ gforth |
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\g @code{name} execution: @code{addr1 -- addr1+offset1}@* |
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\g create a field @code{name} with offset @code{offset1}, and the type |
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\g given by @code{size align}. @code{offset2} is the offset of the |
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\g next field, and @code{align2} is the alignment of all fields. |
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over nalign \ pad size to full alignment |
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2constant ; |
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1 chars 0 end-struct struct ( -- align size ) \ gforth |
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\g an empty structure, used to start a structure definition. |
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\ type descriptors |
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1 aligned 1 cells 2constant cell% ( -- align size ) \ gforth |
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1 chars 1 chars 2constant char% ( -- align size ) \ gforth |
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1 faligned 1 floats 2constant float% ( -- align size ) \ gforth |
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1 dfaligned 1 dfloats 2constant dfloat% ( -- align size ) \ gforth |
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1 sfaligned 1 sfloats 2constant sfloat% ( -- align size ) \ gforth |
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cell% 2* 2constant double% ( -- align size ) \ gforth |
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\ memory allocation words |
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' drop alias %alignment ( align size -- align ) \ gforth |
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\g the alignment of the structure |
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' nip alias %size ( align size -- size ) \ gforth |
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\g the size of the structure |
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: %align ( align size -- ) \ gforth |
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\G align the data space pointer to the alignment @code{align}. |
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drop here swap nalign here - allot ; |
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: %allot ( align size -- addr ) \ gforth |
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\g allot @code{size} address units of data space with alignment |
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\g @code{align}; the resulting block of data is found at |
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\g @code{addr}. |
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tuck %align |
here swap allot ; |
here swap allot ; |
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: struct-allocate ( size align -- addr ior ) |
: %allocate ( align size -- addr ior ) \ gforth |
drop allocate ; |
\g allocate @code{size} address units with alignment @code{align}, |
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\g similar to @code{allocate}. |
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nip allocate ; |
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: %alloc ( size align -- addr ) \ gforth |
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\g allocate @code{size} address units with alignment @code{align}, |
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\g giving a data block at @code{addr}; @code{throw}s an ior code |
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\g if not successful. |
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%allocate throw ; |