Add IO component (like a ME interface)

IO.lua

@@ -0,0 +1,38 @@
+local d = require "luadash"
+local w = require "lib"
+
+local conf = w.load_config({
+    "chest",
+    "items"
+}, {
+    items = {}
+})
+
+w.init()
+
+local chest = peripheral.wrap(conf.chest)
+
+while true do
+    local stacks_stored = chest.list()
+    local items_stored = w.collate_stacks(stacks_stored)
+
+    for item_name, quantity_desired in pairs(conf.items) do
+        local quantity_stocked = items_stored[item_name] or 0
+        if quantity_desired > quantity_stocked then -- if we have fewer items than are desired, extract some from store
+            local request = w.string_to_item(item_name)
+            request.type = "extract"
+            request.destination_inventory = w.chest
+            w.query_by_type("storage", request)
+        end
+    end
+
+    for slot, item in pairs(stacks_stored) do
+        if not items[get_internal_identifier(item)] then -- if item is not in want list, send it back to storage
+            w.query_by_type("storage", {
+                type = "insert",
+                from_inventory = conf.chest,
+                from_slot = slot
+            })
+        end
+    end
+end

lib.lua

@@ -177,6 +177,13 @@ local function get_internal_identifier(item)
     return n
 end
 
+-- Inverse of get_internal_identifier - parses that kind of string into ID/meta/NBT
+local function string_to_item(s)
+    local mod, item, meta, NBT = string.match(s, "(%a+):(%a+):([0-9]+)#([0-9a-f]+)")
+    if not mod or not item or not meta then error(w.errors.make(w.errors.INTERNAL, "string did not match regex")) end
+    return { ID = mod .. ":" .. item, meta = meta, NBT = NBT }
+end
+
 -- GENERAL STUFF
 
 -- Converts a table of the form {"x", "x", "y"} into {x = 2, y = 1}