| \ data structures (like C structs) |
\ data structures (like C structs) |
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| \ Copyright (C) 1995 Free Software Foundation, Inc. |
\ Copyright (C) 1995, 1997 Free Software Foundation, Inc. |
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| \ This file is part of Gforth. |
\ This file is part of Gforth. |
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|
| \ along with this program; if not, write to the Free Software |
\ along with this program; if not, write to the Free Software |
| \ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
\ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
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: naligned ( addr1 n -- addr2 ) \ gforth |
| \ Usage example: |
\g @var{addr2} is the aligned version of @var{addr1} with respect to the |
| \ |
\g alignment @var{n}. |
| \ 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 ) |
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| \ addr2 is the aligned version of addr1 wrt the alignment size n |
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| 1- tuck + swap invert and ; |
1- tuck + swap invert and ; |
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| : field ( offset1 align1 size align -- offset2 align2 ) |
' naligned alias nalign \ old name, obsolete |
| \ note: this version uses local variables |
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| [IFDEF] (Field) (Field) [ELSE] Header reveal dofield: cfa, [THEN] |
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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 ) |
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| \ create-field |
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| \ does> ( addr1 -- addr2 ) |
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| \ @ + ; |
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| \ I don't really like the "type:" syntax. Any other ideas? - anton |
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| \ Also, this seems to be somewhat general. It probably belongs to some |
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| \ other place |
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| : cells: ( n -- size align ) |
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| cells cell ; |
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| : doubles: ( n -- size align ) |
: dozerofield ( -- ) |
| 2* cells cell ; |
\ a field that makes no change |
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\ to enable accessing the offset with "['] <field> >body @" this |
| : chars: ( n -- size align ) |
\ is not implemented with "['] noop alias" |
| chars 1 chars ; |
last @ |
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if |
| : floats: ( n -- size align ) |
immediate |
| floats 1 floats ; |
then |
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does> ( name execution: -- ) |
| : dfloats: ( n -- size align ) |
drop ; |
| dfloats 1 dfloats ; |
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| : sfloats: ( n -- size align ) |
: field, ( align1 offset1 align size -- align2 offset2 ) |
| sfloats 1 sfloats ; |
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 @code{name} execution: @var{addr1} -- @var{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: @var{addr1} -- @var{addr1+offset1}@* |
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\g Create a field @var{name} with offset @var{offset1}, and the type |
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\g given by @var{size align}. @var{offset2} is the offset of the |
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\g next field, and @var{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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| : struct-align ( size align -- ) |
1 chars 0 end-struct struct ( -- align size ) \ gforth |
| dp @ swap nalign dp ! |
\g An empty structure, used to start a structure definition. |
| drop ; |
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| : struct-allot ( size align -- addr ) |
\ type descriptors |
| over swap struct-align |
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 @var{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 @var{size} address units of data space with alignment |
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\g @var{align}; the resulting block of data is found at |
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\g @var{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 @var{size} address units with alignment @var{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 @var{size} address units with alignment @var{align}, |
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\g giving a data block at @var{addr}; @code{throw} an ior code |
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\g if not successful. |
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%allocate throw ; |
