Using Multiple Variables to Reference a Sub-Sub-Sub Field in a Lua Dictionary - dictionary

Question

I'm new to Lua (like, yesterday new), so please bear with me...
I apologize for the convoluted nature of this question, but I had no better idea of how to demonstrate what I'm trying to do:
I have a Lua table being used as a dictionary. The tuples(?) are not numerically indexed, but use mostly string indices. Many of the indices actually relate to sub-tables that contain more detailed information, and some of the indices in those tables relate to still more tables - some of them three or four "levels" deep.
I need to make a function that can search for a specific item description from several "levels" into the dictionary's structure, without knowing ahead of time which keys/sub-keys/sub-sub-keys led me to it. I have tried to do this using variables and for loops, but have run into a problem where two keys in a row are being dynamically tested using these variables.
In the example below, I'm trying to get at the value:
myWarehouselist.Warehouse_North.departments.department_one["rjXO./SS"].item_description
But since I don't know ahead of time that I'm looking in "Warehouse_North", or in "department_one", I run through these alternatives using variables, searching for the specific Item ID "rjXO./SS", and so the reference to that value ends up looking like this:
myWarehouseList[warehouse_key].departments[department_key][myItemID]...?
Basically, the problem I'm having is when I need to put two variables back-to-back in the reference chain of a value being stored at level N of a dictionary. I can't seem to write it out as [x][y], or as [x[y]], or as [x.y] or as [x].[y]... I understand that in Lua, x.y is not the same as x[y] (the former directly references a key by string index "y", while the latter uses the value being stored in variable "y", which could be anything.)
I've tried many different ways and only gotten errors.
What's interesting is that if I use the exact same approach, but add an additional "level" to the dictionary with a constant value, such as ["items"] (under each specific department), it allows me to reference the value without issue, and my script runs fine...
myWarehouseList[warehouse_key].departments[department_key].items[item_key].item_description
Is this how Lua syntax is supposed to look? I've changed the table structure to include that extra layer of "items" under each department, but it seems redundant and unnecessary. Is there a syntactical change that I can make to allow me to use two variables back-to-back in a Lua table value reference chain?
Thanks in advance for any help!
myWarehouseList = {
["Warehouse_North"] = {
["description"] = "The northern warehouse"
,["departments"] = {
["department_one"] = {
["rjXO./SS"] = {
["item_description"] = "A description of item 'rjXO./SS'"
}
}
}
}
,["Warehouse_South"] = {
["description"] = "The southern warehouse"
,["departments"] = {
["department_one"] = {
["rjXO./SX"] = {
["item_description"] = "A description of item 'rjXO./SX'"
}
}
}
}
}
function get_item_description(item_id)
myItemID = item_id
for warehouse_key, warehouse_value in pairs(myWarehouseList) do
for department_key, department_value in pairs(myWarehouseList[warehouse_key].departments) do
for item_key, item_value in pairs(myWarehouseList[warehouse_key].departments[department_key]) do
if item_key == myItemID
then
print(myWarehouseList[warehouse_key].departments[department_key]...?)
-- [department_key[item_key]].item_description?
-- If I had another level above "department_X", with a constant key, I could do it like this:
-- print(
-- "\n\t" .. "Item ID " .. item_key .. " was found in warehouse '" .. warehouse_key .. "'" ..
-- "\n\t" .. "In the department: '" .. dapartment_key .. "'" ..
-- "\n\t" .. "With the description: '" .. myWarehouseList[warehouse_key].departments[department_key].items[item_key].item_description .. "'")
-- but without that extra, constant "level", I can't figure it out :)
else
end
end
end
end
end

Answer 1

If you make full use of your looping variables, you don't need those long index chains. You appear to be relying only on the key variables, but it's actually the value variables that have most of the information you need:
function get_item_description(item_id)
for warehouse_key, warehouse_value in pairs(myWarehouseList) do
for department_key, department_value in pairs(warehouse_value.departments) do
for item_key, item_value in pairs(department_value) do
if item_key == item_id then
print(warehouse_key, department_key, item_value.item_description)
end
end
end
end
end
get_item_description'rjXO./SS'
get_item_description'rjXO./SX'