Refactored nature classic global functions

nature_classic/global_function.lua

 local NODE_YOUNG = "young"
 
+local SETTING_TRUE = "true"
+local SETTING_FALSE = "false"
+
+local YOUTH_DELAY = 5
+
 nature = {}
 
 local function set_young_node(pos)
     local meta = minetest.get_meta(pos)
 
-    meta:set_string(NODE_YOUNG, "true")
-    minetest.after(5,
-	function(pos)
-	    local meta = minetest.get_meta(pos)
-	    meta:set_string(NODE_YOUNG, "false")
-	end,
+    meta:set_string(NODE_YOUNG, SETTING_TRUE)
+    minetest.after(YOUTH_DELAY,
+        function(pos)
+            local meta = minetest.get_meta(pos)
+            meta:set_string(NODE_YOUNG, SETTING_FALSE)
+        end,
     pos)
 end
 
@@ -18,26 +23,26 @@ local function is_not_young(pos)
     local meta = minetest.get_meta(pos)
 
     local young = meta:get_string(NODE_YOUNG)
-    return young ~= "true"
+    return young ~= SETTING_TRUE
 end
 
 function nature:grow_node(pos, nodename)
     if pos ~= nil then
-	local light_enough = minetest.get_node_light(pos, nil)
-		>= MINIMUM_GROWTH_LIGHT 
+        local light_enough = minetest.get_node_light(pos, nil)
+                >= MINIMUM_GROWTH_LIGHT 
 
-	if is_not_young(pos) and light_enough then
-	    minetest.remove_node(pos)
-	    minetest.set_node(pos, { name = nodename })
-	    set_young_node(pos)
+        if is_not_young(pos) and light_enough then
+            minetest.remove_node(pos)
+            minetest.set_node(pos, { name = nodename })
+            set_young_node(pos)
 
-	    minetest.log("info", nodename .. " has grown at " .. pos.x .. ","
-		.. pos.y .. "," .. pos.z)
-	end
+            minetest.log("info", nodename .. " has grown at " .. pos.x .. ","
+                .. pos.y .. "," .. pos.z)
+        end
     end
 end
 
 function nature:is_near_water(pos)
-    return minetest.find_node_near(pos, DISTANCE_FROM_WATER,
-	    { "default:water_source" }) ~= nil or DISTANCE_FROM_WATER == -1
+    return DISTANCE_FROM_WATER == -1 or minetest.find_node_near(pos, DISTANCE_FROM_WATER,
+            { "default:water_source" }) ~= nil
 end