variables and API's. How do I properly reference to them?

--[[
This API is created to provide Turtles functions to keep
track of their relative location while moving around.
Basically, after moving or turning I would like to save this information in a file.
Just in case the server shuts down or the chunk unloads.
]]--

--current location--create variables
-- used to be "local x = 0" but that didn't work either
x = 0
y = 0
z = 0

--current direction
d = 0

--[[
support functions:
getLocation FromFile

]]--

--getLocation
function getLocation()
locationFile = fs.open("location", "r")
directionFile = fs.open("direction", "r")
d = tonumber(locationFile.readAll())
gx, gy, gz = locationFile.readAll():match("([^,]+),([^,]+), ([^,]+)")
x, y, z = tonumber(gx), tonumber(gy), tonumber(gz)
locationFile.close()
directionFile.close()
end

--setLocation and direction
function setLocation()
location = "" .. x .. "," .. y .. "," .. z      --this is line 33
direction = "" .. d
locationFile = fs.open("location", "w")
locationFile.write(location)
locationFile.close()

directionFile = fs.open("direction", "w")
directionFile.write(direction)
directionFile.close()
end


--movement functions
function registerMove(amount)
if d == 0 then
y = y+amount
elseif d == 1 then
x = x+amount
elseif d == 2 then
y = y-amount
elseif d == 3 then
x = x-amount
end
end

function move(amount)
for x = 0, amount-1, 1 do
getLocation()
if turtle.forward() then
registerMove()
setLocation()
end
end
end

function moveV(amount)
for x = 0, amount-1, 1 do
getLocation()
if turtle.forward() then
z = z+amount
setLocation()
end
end

end

function turnLaft()
getLocation()
turtle.turnLeft()
if d > 1 then
d = d-1
else
d = 4
end
setLocation()

end

function turnRaight()
getLocation()
turtle.turnRight()
if d < 4 then
d = d+1
else
d = 1
end
setLocation()
end

function init()
x = 0
y = 0
z = 0
d = 0
setLocation()
end

os.loadAPI("movementAPI")
movementAPI.init()
movementAPI.move(5)

location = "" .. x .. "," .. y .. "," .. z

Bomb Bloke, on 13 August 2014 - 08:20 PM said:

Nah, you're referring to them correctly. Odds are it's to do with the function above - if gx/gy/gz don't represent valid numbers for any reason, then tonumber(gx)/tonumber(gy)/tonumber(gz) will return nil.

location=textutils.serialize(locationfile.readall())

hilburn, on 13 August 2014 - 09:33 PM said:

why not do:

location=textutils.serialize(locationfile.readall())

much better to use vectors/tables for doing location stuff

gx, gy, gz = locationFile.readAll():match("([^,]+),([^,]+), ([^,]+)")

Crucidal, on 13 August 2014 - 09:06 PM said:

Actually, I didn't use that function yet.

hilburn, on 13 August 2014 - 09:33 PM said:

why not do:

local myVars = {["x"] = 0, ["y"] = 0, ["z"] = 0, ["d"] = 0}

--setLocation and direction
local function setLocation()
	local locationFile = fs.open("location", "w")
	locationFile.write(textutils.serialise(myVars))
	locationFile.close()
end

--getLocation
function getLocation()
	local locationFile = fs.open("location", "r")
	myVars = textutils.unserialise(locationFile.readAll())
	locationFile.close()
end

Crucidal, on 13 August 2014 - 10:34 PM said:

gx, gy, gz = locationFile.readAll():match("([^,]+),([^,]+), ([^,]+)")

this code doesn't seem to work but I don't know how else to do this… any ideas?

gx, gy, gz = locationFile.readAll():match("(.*%d*),(.*%d*),(.*%d*)")

Bomb Bloke, on 14 August 2014 - 03:40 AM said:

Crucidal, on 13 August 2014 - 10:34 PM said:

gx, gy, gz = locationFile.readAll():match("([^,]+),([^,]+), ([^,]+)")

this code doesn't seem to work but I don't know how else to do this… any ideas?

Something like this:

gx, gy, gz = locationFile.readAll():match("(.*%d*),(.*%d*),(.*%d*)")

The stuff outside the brackets has to be matched verbatim - that includes spaces, so be careful! Within the brackets, ".*" means "get everything until the next match", and "%d*" means "get all digits until the next match".

It may be that you can't apply "match" directly to "locationFile.readAll()". You may need to read the file contents into a variable, then apply "match" to that variable on the following line.

local str="1234567890"
local dot1,number1=str:match("(.*)(%d*)")
local dot2,number2=str:match("(.-)(%d+)")
print(dot1,"|",number1)
print(dot2,"|",number2)

natedogith1, on 14 August 2014 - 06:15 AM said:

I'd recomend using something along the lines of '.-(%d+),.-(%d+),.-(%d+)' , as it doesn't return the unnecessary white space characters.

Bomb Bloke, on 14 August 2014 - 06:58 AM said:

natedogith1, on 14 August 2014 - 06:15 AM said:

I'd recomend using something along the lines of '.-(%d+),.-(%d+),.-(%d+)' , as it doesn't return the unnecessary white space characters.

True, but there shouldn't be any white space. While I'm sure my expression can be improved (I've got a nagging feeling it doesn't need the %d*'s at all), it does have the benefit of being able to handle decimal points and negative values.

Though seriously, I'm no pattern expert. I just bashed stuff into repl.it according to this guide until it worked.

Bomb Bloke, on 14 August 2014 - 03:40 AM said:

Anyway, to elaborate on this, it'd work along these lines: First you'd initialise a table with your values in it:

natedogith1, on 14 August 2014 - 06:15 AM said:

Bomb Bloke, on 14 August 2014 - 03:40 AM said:

Crucidal, on 13 August 2014 - 10:34 PM said:

gx, gy, gz = locationFile.readAll():match("([^,]+),([^,]+), ([^,]+)")

this code doesn't seem to work but I don't know how else to do this… any ideas?

Something like this:

gx, gy, gz = locationFile.readAll():match("(.*%d*),(.*%d*),(.*%d*)")

The stuff outside the brackets has to be matched verbatim - that includes spaces, so be careful! Within the brackets, ".*" means "get everything until the next match", and "%d*" means "get all digits until the next match".

It may be that you can't apply "match" directly to "locationFile.readAll()". You may need to read the file contents into a variable, then apply "match" to that variable on the following line.

The stuff outside the brackets works in the funny way of regular expressions, it's the stuff inside that's more exact(I think), though it's more of an or(or a nor because of the begining '^').

I'd recomend using something along the lines of '.-(%d+),.-(%d+),.-(%d+)' , as it doesn't return the unnecessary white space characters. The difference between the '*' and the '-' is potentially very important as it's the difference between '12,12,12' returning three twos or three twelves in this case. The '*' is hungry, it eats the string and gives back what's needed, while the '-' isn't hungry, therefore it leaves behind as much of the string as it can.

local str="1234567890"
local dot1,number1=str:match("(.*)(%d*)")
local dot2,number2=str:match("(.-)(%d+)")
print(dot1,"|",number1)
print(dot2,"|",number2)

With the above, dot1 will contain the entire string, while number1 will be an empty string. However, with the second regular expression, dot2 will be an empty string and number2 will be the number, which is much closer to what we want.

Also, checking it out, it seems that your issue was an accidental space, as (I think) Bomb Bloke mentioned.