Reverse last n items on the stack

stack.fs

: create-stack
  dup
  1 + cells allocate throw dup 0 swap !
  over over swap cells erase
  swap drop
; 

: write-on-top ( address n -- address )  swap dup dup @ 1 + cells + rot swap ! ;

: move-cursor ( address n -- address ) over dup @ rot + swap ! ;

: push ( address n -- address )
  write-on-top
  1 move-cursor
;

: pop ( address -- n address )
  dup dup @ cells + @  swap -1 move-cursor  ;

: is-empty ( address -- address flag )
  dup @ 0= ;


: reverse-stack { i } ( n1 n2 ... ni i -- ni ni-1 ... n2 n1 )
		
  i create-stack

  i 0 do
    swap push
  loop

  i create-stack
  
  i 0 do
    over pop drop push
  loop

  swap

  free throw

  i 0 do
    pop
  loop

  free throw
;


1 2 3 4 5

.s cr

5 reverse-stack

.s cr

5 reverse-stack

.s cr

bye