WIP solution to JohnEarnest's Forth Warrior. It looks, acts upon what is there, if it is a floor or stairs it will add that to the 'walkables' var. At 'move' it asks if it needs to think or not (if there's more than one possible path or not) and moves accordingly.

warrior.fs

( Current ToDo:
    * Fix direction bug when picking up gem
    * Figure out how to have it decide where to go when it has more than 1 path
)

: allot loop 0 , 1- dup while drop ;
create walkables 4 allot
create from -1 ,
var n-dirs

: rot  >r swap r> swap         ; ( a b c -- c b a )
: abs  dup 0< if -1 / then     ; ( n -- |n| )
: add  abs n-dirs @ + n-dirs ! ; ( flag --  )
: resetVars 0 n-dirs !         ; ( -- )
: walks@    walkables + @      ; ( dir -- flag )
: walks!    walkables + !      ; ( dir flag -- )

# Looking words
: from?   from @    =                  ; ( dir  -- flag )
: attack? SLIME     =                  ; ( type -- flag )
: take?   dup GEM   = swap KEY    = or ; ( type -- flag )
: walk?   dup FLOOR = swap STAIRS = or ; ( type -- flag )
: do?     dup take?   swap attack?  or ; ( type -- flag )

: act ( dir -- )
    dup from?   if 0 swap walks! exit then
    dup look
    dup do? if
        dup attack? if attack then
        dup take?   if take   then FLOOR then
    dup walk? dup add rot walks! drop
;

: search ( -- )
    N act
    E act
    S act
    W act
;

# Moving words
: opp    2 + 4 mod      ; ( dir -- opp ) # Opposite
: from!  opp from !     ; ( dir -- )
: Walk   dup from! walk ; ( dir -- )

: one-move ( -- )
    N walks@ if N Walk exit then
    S walks@ if S Walk exit then
    E walks@ if E Walk exit then
    W walks@ if W Walk exit then
;
: multi-move one-move ; # Placeholder

: move ( -- )
    n-dirs @
    dup 1> if multi-move else
    dup 1= if one-move   else
    -1 from ! then then  drop
;

# Test loop
: brain
    loop
        search
        move
        resetVars
    again
;