2 posts
Posted 09 December 2013 - 08:19 PM
I was playing FTB Mindcrack Pack (a minecraft mod pack with Computer Craft) and thought to myself, I really want some storage automation. I have minimal knowlege of lua and turtles, but i do know thier basic functions/Api (and the rednet API) and have looked at basic lua. I am a programmer; I have a lot of experience in c++, however, am hopeless every time i try lua and CC :)/> . However, I would like to know what the best way to tackle auto retrieving and pushing things to a storage system would be.
The way I would do it in c++ (i only understand c++, lua looks like gobbledeegook) :
// - double slash = comment in c++/java for lua-only people :)/>/>/>
// computer 1
string itemType = " "
string amount = " "
std::cout << "type Item type"; // standard c++ output
std::cin >> itemType; //standard c++ input
rednet.open ("right");
rednet.broadcast (itemType);
id, message = rednet.recieve();
if (message == "has item")
{
std::cout << "Amount?";
std::cin >> amount;
rednet.broadcast (amount);
id, message = rednet.recieve();
if (message == "has amount")
{
std::cout << "Everything clear. Will recieve items.";
}
if (message != "has item") // != is the not operator in c++ / any language w/ boolean operators
{
std::cout << "Not enough Items, sorry.";
}
}
if (message != "has item")
{
std::cout << "No item of that type in storage, sorry."
}
I have been using c++ for so long, I don't even begin to understand lua. Everything I try to write is semicoloned and with {} brackets :)/> If someone will give me pointers as to how i could convert this to lua, i would be very happy. Ty. :D/>
Edited on 09 December 2013 - 08:15 PM
7083 posts
Location
Tasmania (AU)
Posted 09 December 2013 - 10:26 PM
-- - double dash = A comment in Lua.
-- computer 1
local itemType,amount -- Data types can be changed at will and so aren't specified.
-- Variables are also globalised unless you specify otherwise, hence good practise is to localise them.
print("Type in the desired item type:") -- Standard Lua output.
itemType = read() -- ComputerCraft's general "get text from user" function.
rednet.open("right"); -- Note that semi-colons may be used, but are optional.
rednet.broadcast(itemType)
local id, message = rednet.receive() -- "Receive" is spelt with an "ei".
if message == "has item" then -- Brackets are optional (depending on the complexity of your conditional), braces aren't used, "then" is mandatory.
print("Amount?")
amount = tonumber(read()) -- "read()" returns strings. "tonumber()" converts type where possible.
rednet.broadcast (amount)
id, message = rednet.receive()
if message == "has amount" then
print("Everything clear. Will recieve items.")
elseif message ~= "has item" then -- Use "~=" instead of "!=".
print("Not enough Items, sorry.")
end -- For all intents and purposes, "end" is the same as "}".
-- Presumably the other system can return "has amount", "has item", or something else...?
else -- I'll assume you're familiar with "else" and "elseif".
print("No item of that type in storage, sorry.")
end
rednet.close("right")
7508 posts
Location
Australia
Posted 09 December 2013 - 10:33 PM
if (message == "has item")
Unrelated to the problem at hand but, technically in C++ shouldn't that be
if (strcmp(message, "has item"))
or
if (message.compare("has item"))
Everything I try to write is semicoloned
You can end lines in Lua with a semi-colon, it is valid syntax :)/>
2 posts
Posted 10 December 2013 - 05:17 PM
if (message == "has item")
Unrelated to the problem at hand but, technically in C++ shouldn't that be
if (strcmp(message, "has item"))
or
if (message.compare("has item"))
Everything I try to write is semicoloned
You can end lines in Lua with a semi-colon, it is valid syntax :)/>
Yay semicolons! :P/>
Thank you :)/> I now know some basic lua through your translation.
Thanks for the help, but it looks like i need a little more. For some reason it doesen't like my "end" statements even though i think i put enough:
function allTheThings ()
if numbItems > 64 then
turtle.suckUp()
numbItems = numbItems - 64
end
elseif numbItems < 64 then
turtle.suckUp()
itemCount = turtle.getItemCount(1)
amountBack = 64 - itemCount
turtle.dropUp(amountBack)
end
turtle.turnLeft()
turtle.turnLeft()
turtle.drop()
turtle.turnRight()
turtle.turnRight()
end
rednet.open("right")
id, message = rednet.recieve()
if id == "pc1" and message == "cobble" then
id, message = rednet.recieve()
if id == "pc1" then
numbItems = message
while numbItems > 0 do
allTheThings()
end
It thinks that there is no "end" to close the first function, I put one in there. Is there some special requirement rather than just putting it at the end?
621 posts
Location
U.S.A.
Posted 10 December 2013 - 10:59 PM
I doubt this is correct, but whenever I get that error, if I add 3 or 4 more 'end' statements, it works about 50% of the time. I'm interested in a proper answer to this as well.
7508 posts
Location
Australia
Posted 10 December 2013 - 11:26 PM
an
if statement doesn't need an end if there's an
elseif.
if [condition] then
-- statement
end
if [condition] then
-- statement
else
-- statement
end
if [condition] then
-- statement
elseif [condition] then
-- statement
end
131 posts
Posted 13 December 2013 - 12:03 AM
Remember that in Lua,
else if
is
different from
elseif
That was one of the things that got me when transitioning to Lua.
This is what it needs to look like if you leave that whitespace between
else and
if:
if [condition] then
-- statement
else
if [condition] then
-- statement
end
end
If you leave
any space, it treats the second
if as the opening of another branching statement, instead of the continuation of the previous branching statement.
Edited on 12 December 2013 - 11:06 PM