private vocabulary chains

variable this
variable that
: chain create here !that 0 , here !this 2 allot ;
: +link here push @this , @last , pop !this @@last !last ;
: seal @this @that ! ;

variable flag
variable xt
variable str
: zdrop ( n-n | nz-z ) dup 0 =if 2drop 0 then ;
: (search) ( a-fa )
  repeat
    @ 0; dup 1+ @ zdrop 0;
    d->name @str compare if flag on dup 1+ @ zdrop 0; d->xt @ !xt drop ;then
  again ;
: search-chain ( a$- )
  !str 0 !xt 0 !flag
  (search) @xt @flag ;

( ~~~~~~~~~~~~~~~~~~~~~~ TEST STUFF ~~~~~~~~~~~~~~~~~~~~~~~~ )

: walk ( a- ) repeat @ 0; dup 1+ @ zdrop 0; d->name type space again ;

chain oo
  : foo 1 . ; +link
  : bar 1 . ; +link
  : biz 1 . ; +link
  : bag 1 . ; +link
seal

oo walk

oo " bar" search-chain .s reset
oo " zdabar" search-chain .s reset