How do I procedurally iterate through similar variables in Lua?

Question

I have a lot of variables that seem to lend themselves to be referenced a lot easier, but I'm not sure how to do it; the variable names are related to entries on a coordinate system, and where they are written to is also coordinate based. I have tried searching google, I've gone through the Lua documentation, but as I'm not sure what I'm looking for I think that is hindering my search. Here is how the variables look in an excerpt of my code:

-- Bank 1

local Object111 =  sItem.getTargetDetails("-4,3,-4")
local Object112 =  sItem.getTargetDetails("-5,3,-4")
local Object113 =  sItem.getTargetDetails("-6,3,-4")
local Object114 =  sItem.getTargetDetails("-7,3,-4")
local Object115 =  sItem.getTargetDetails("-8,3,-4")

local Object121 =  sItem.getTargetDetails("-4,4,-4")
local Object122 =  sItem.getTargetDetails("-5,4,-4")
local Object123 =  sItem.getTargetDetails("-6,4,-4")
local Object124 =  sItem.getTargetDetails("-7,4,-4")
local Object125 =  sItem.getTargetDetails("-8,4,-4")

local Object131 =  sItem.getTargetDetails("-4,5,-4")
local Object132 =  sItem.getTargetDetails("-5,5,-4")
local Object133 =  sItem.getTargetDetails("-6,5,-4")
local Object134 =  sItem.getTargetDetails("-7,5,-4")
local Object135 =  sItem.getTargetDetails("-8,5,-4")

-- Bank 2

local Object211 =  sItem.getTargetDetails("-4,3,1")
local Object212 =  sItem.getTargetDetails("-5,3,1")
local Object213 =  sItem.getTargetDetails("-6,3,1")
local Object214 =  sItem.getTargetDetails("-7,3,1")
local Object215 =  sItem.getTargetDetails("-8,3,1")

local Object221 =  sItem.getTargetDetails("-4,4,1")
local Object222 =  sItem.getTargetDetails("-5,4,1")
local Object223 =  sItem.getTargetDetails("-6,4,1")
local Object224 =  sItem.getTargetDetails("-7,4,1")
local Object225 =  sItem.getTargetDetails("-8,4,1")

local Object231 =  sItem.getTargetDetails("-4,5,1")
local Object232 =  sItem.getTargetDetails("-5,5,1")
local Object233 =  sItem.getTargetDetails("-6,5,1")
local Object234 =  sItem.getTargetDetails("-7,5,1")
local Object235 =  sItem.getTargetDetails("-8,5,1")

I would then proceed to call each of these variables in a function, where the position on screen is a function of the numbers in the name, the first two numbers relating to x coords and the last number to the y coords:

mon.setCursorPos(4,4)
mon.write(Object111.StoredPercentage)
mon.setCursorPos(10,4)
mon.write(Object112.StoredPercentage)
mon.setCursorPos(16,4)
mon.write(Object113.StoredPercentage)
...
mon.setCursorPos(8,4)
mon.write(Object121.StoredPercentage)
mon.setCursorPos(8,4)
mon.write(Object121.StoredPercentage)
...
mon.setCursorPos(36,4)
mon.write(Object211.StoredPercentage)
mon.setCursorPos(42,4)
mon.write(Object212.StoredPercentage)
mon.setCursorPos(48,4)
mon.write(Object213.StoredPercentage)
etc....

I can see that this should be able to be generated on the fly, but I don't know where to start without calling it out manually; I would prefer it if my code was cleaner. At this stage I really just need to be taught how to fish; if anyone can point me to documents that explain how to do what I'm trying to I would be most grateful.

There is a way of accessing `local variables` in `Lua`. Check the [PiL: debug.getlocal()](http://www.lua.org/pil/23.1.1.html). Another similar already answered question is [here](http://stackoverflow.com/a/2835433/1150918). If I were You, I'd try to avoid this kind of clotting and put those objects into local scoped table. — Kamiccolo, Sep 01 '14 at 09:11
Yes! I really am showing my greeness... Tables are the first step to solving my problem; I have some reading to do. Can you give me some pointers on how to break down a associative array variable name so I can take the last number from Object111 to calculate the x coord, and the first two to calculate the y coord? Thanks! — fileinsert, Sep 01 '14 at 09:41
Don't worry... I got it! I'll post my results once I'm finished. Thanks again... you gave me all the little push I needed. — fileinsert, Sep 01 '14 at 10:27

fileinsert · Accepted Answer · 2014-09-02T10:13:20.883

3

Here's my final solution for anyone trying to achieve same:

local Banks = 2
local Rows = 3
local Columns = 5

function Objectstatus(bank,row,column)

    Id = bank .. row .. column
    worldx = "-" .. column+3
    worldy = row+2
    if bank == 1 then worldz = -4; end
    if bank == 2 then worldz = 1; end
    Object = {}
    Object[Id] = s.getTargetDetails(worldx..","..worldy..","..worldz)
    xcursor = (column*7)+3
    if bank == 1 then 
        ycursor = (row*4)+8
    end
    if bank == 2 then 
        ycursor = (row*4)+24
    end

    mon.setCursorPos(xcursor,ycursor)
    powertext(Object[Id].StoredPercentage) -- A function that sets Texts settings based on result
    mon.write(Object[Id].StoredPercentage) -- Actually writes the result
end

    for BankTemp = 1, Banks do
        for ColumnTemp = 1, Columns do
            for RowTemp = 1, Rows do
            Objectstatus(BankTemp,RowTemp,ColumnTemp)
            end
        end
    end

edited Sep 02 '14 at 10:13

answered Sep 01 '14 at 11:41

fileinsert

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4
22

one tiny suggestion - I'd make `Id`, `worldx`, `worldy`, `xcursor`, `ycursor` `local` ones too. This way it won't clog `global` space and perform a little bit faster. – Kamiccolo Sep 02 '14 at 09:12
The way I have written my script means these variables are called outside the function, which I believe means they have to be global unless I am mistaken. But thanks for the continuing advice as it is warmly received. – fileinsert Sep 02 '14 at 10:10
1

uffff... it's not the best practice. You know, in Lua functions can return multiple values? Ref.: PiL5.1 - [multiple results](http://www.lua.org/pil/5.1.html) – Kamiccolo Sep 02 '14 at 13:27

How do I procedurally iterate through similar variables in Lua?

1 Answers1