version 1.10, 1997/03/21 12:21:13
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version 1.18, 2000/09/23 15:46:59
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\ data structures (like C structs) |
\ data structures (like C structs) |
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\ Copyright (C) 1995 Free Software Foundation, Inc. |
\ Copyright (C) 1995,1997,2000 Free Software Foundation, Inc. |
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\ This file is part of Gforth. |
\ This file is part of Gforth. |
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\ You should have received a copy of the GNU General Public License |
\ You should have received a copy of the GNU General Public License |
\ 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., 59 Temple Place, Suite 330, Boston, MA 02111, 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 |
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\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 ) |
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2* cells cell ; |
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: chars: ( n -- size align ) |
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chars 1 chars ; |
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: floats: ( n -- size align ) |
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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 Create a field @var{name} with offset @var{offset1}, and the type |
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\g given by @var{align size}. @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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\g @code{name} execution: @var{addr1} -- @var{addr2}.@* |
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\g @var{addr2}=@var{addr1}+@var{offset1} |
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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 Define a structure/type descriptor @var{name} with alignment |
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\g @var{align} and size @var{size1} (@var{size} rounded up to be a |
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\g multiple of @var{align}).@* |
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\g @code{name} execution: -- @var{align size1}@* |
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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 @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 ; |