GForth structs

sllist-less-comments.fs

https://gist.github.com/tkurtbond/b629cdff2d70e31b0e1527f1ead14462

https://gforth.org/manual/Gforth-structs.html

\ sllist-less-comments.fs - Реализация односвязного списка в forth с использованием структур gforth, и немного комментариев.

struct
    cell% field node-text               \ address of counted string - адрес строки
    cell% field node-next               \ address of next node      - адрес следующей ноды.
end-struct node%

: node-init ( text-addr next-addr node-addr -- ) tuck   node-next !   node-text ! ;

: node-type ( node-addr -- )   node-text @ count type ;

: node-traverse ( first-addr -- ) 
    begin dup @ 0<> while cr dup @ node-type @ node-next repeat drop
;

: node-text-compare ( node1-addr node2-addr -- flag )
    node-text @ count rot node-text @ count 2swap compare
;

: node-insert ( new-node-addr p-addr )
    dup @ 0= if ! exit then             
    2dup @ node-text-compare -1 = if 2dup @   swap node-next !   !   exit then
    begin
        dup @ node-next @ 0<>
    while 
        2dup @ node-text-compare 1 =
    while
        @ node-next
    repeat then
    2dup   @ node-next @  swap  
    node-next ! 
    @ node-next !
;

\ Build the initial list manually.
\ Create some strings.
create s1 ," one"
create s2 ," two"
create s3 ," three"

s1   ok 1
.s <1> 139881123671816  ok 1
count  ok 2
.s <2> 139881123671817 3  ok 2
type one ok

\ Create some nodes and initialize them, making links between them.
node% %allot constant n1
node% %allot constant n2
node% %allot constant n3

\ ( text-addr next-addr node-addr -- )
s3  0 n3 node-init
s2 n3 n2 node-init
s1 n2 n1 node-init

\ указатель на список (на первый элемент списка)
variable l1
n1 l1 !

\ создал ноду
node% %allot constant n4

\ : node-init ( text-addr next-addr node-addr -- ) tuck   node-next !   node-text ! ;

\ запись данных
 0 n4 node-next !
s1 n4 node-text !

\ получение данных
\ ( node-addr -- ) <имя поля> @ 
n4 node-next @ .

n4 node-text @ count type