item usage code

Axe
 tree->PUT air, give wood AND saplings
shovel
 dirt->PUT air, give dirt
 sand->PUT air, give sand
bucket
 water->PUT air, replace water bucket
water bucket
 air->PUT water, replace bucket
pickaxe
 stone->PUT air, give stone
 ore->PUT air, give stone AND ore
 crystals->PUT air, give stone AND crystals

Y1
 *define LIST of pickupable items here*
 wall
 floor

Y2
 tree w/ fruit->PUT tree, give fruit

IF ITEM==#AXE THEN
 IF TILE==#TREE THEN
  GIVEITEM #WOOD,3
  GIVEITEM #SAPLING,1
  RETURN 0
 ENDIF
ELSEIF ITEM==#SHOVEL THEN
 IF TILE==#DIRT THEN
  GIVEITEM #DIRT,1
  RETURN 0
 ELSEIF TILE==#SAND THEN
  GIVEITEM #SAND,1
  RETURN 0
 ENDIF
ELSEIF ITEM==#BUCKET THEN
 IF TILE==#WATER THEN
  GIVEITEM #WATERBUCKET
  RETURN 0
 ENDIF
ELSEIF ITEM==#WATERBUCKET
 IF TILE==#AIR THEN