Adding strings together

local string1 = "a"
local string2 = "b"
local string3 = a..b --# concatenation operator is ..
print(string3) --# prints "ab" without quotes

MyString1 = "fu"
MyString2 = " manchu"
MyString3 = MyString1..Mystring2

Lyqyd, on 24 December 2013 - 10:20 PM said:

Did you mean to use string1 and string2 in you concatenation example? The code you've got there doesn't make any sense, since a and b would both be nil.

MrabEzreb, on 25 December 2013 - 08:50 AM said:

Okay, this I might not need but might be helpful. If "A".."A" = "AA", how do I make "AA" - "A" = "A"?

MrabEzreb, on 25 December 2013 - 09:53 AM said:

so you are saying that A: I need to know every "equation" beforehand and B: the easiest way to do this is with a lot of if's and elseif's?

MrabEzreb, on 25 December 2013 - 08:50 AM said:

Okay, this I might not need but might be helpful. If "A".."A" = "AA", how do I make "AA" - "A" = "A"?

Freack100, on 25 December 2013 - 10:18 AM said:

MrabEzreb, on 25 December 2013 - 08:50 AM said:

Okay, this I might not need but might be helpful. If "A".."A" = "AA", how do I make "AA" - "A" = "A"?

You would have to edit the strings metatable, but that's not possible without editing the bios.

local str = "AA"
--# lets get one A of!
local string = string.sub(str, 1, #str - 1)

local function string.strip(self, str)
	if type(str) ~= "string" then
		error("'String expected, got " .. type(str), 2)
	end

	 local newStr = ""
	 local stripped = true
	 for i = 1, self:len() do
		   if str == self:sub(i, i) and not stripped then
				 stripped = true
		   else
				 newStr = newStr .. self:sub(i, i)
		   end
	 end
	 return newStr
end

--#usage
local str = "AA"
str = str:strip("A")

Engineer, on 25 December 2013 - 11:22 AM said:

-snip-

Engineer, on 25 December 2013 - 11:22 AM said:

local function string.strip(self, str)
	if type(str) ~= "string" then
		error("'String expected, got " .. type(str), 2)
	end

	 local newStr = ""
	 local stripped = true
	 for i = 1, self:len() do
		   if str == self:sub(i, i) and not stripped then
				 stripped = true
		   else
				 newStr = newStr .. self:sub(i, i)
		   end
	 end
	 return newStr
end

--#usage
local str = "AA"
str = str:strip("A")

local function string.strip(self, str) --#this defines a function, [s]I assume that it assigns the function ("strip" with the arguments of "self" and "str") to the "string" api. so that if for example I put this in the file "stripAPI" and then ran os.loadAPI("stripAPI"), I wouldn't type "stripAPI.strip()", I would type "string.strip()". also what type of arguments are these? "str" is a string (obvi), but what is "self"?[/s] scratch that, "string.strip(self, str)" is accually "(string = the string you are stripping from):strip([self = it tells the function that in "string.strip", the "string" is an argument], [str = what you are stripping off])

	if type(str) ~= "string" then --# this determines if "str" is a string or not, if not it runs the "error()" function (I happen to want to figure out how the error() function works btw).
		error("'String expected, got " .. type(str), 2)
	end

	 local newStr = "" -- #defines a empty string to the variable "newStr".
	 local stripped = true --#defines "stripped" as "true".
	 for i = 1, self:len() do -- #will run the following code and set "i" to "1", and then run until "i" is equal to "self:len()". I know what "self" is (the "string" in "string:strip"), but what is ":len()"? from your use of "self" as an argument, "len()" is a function and "self:len()" is "len()" with "self" as its "self" argument. (the function for len() is defined as X.len(self)?)
		   if str == self:sub(i, i) and not stripped then --#will set "stripped" to "true" if A: "stripped" is false and B: "str" is equal to "self:sub(i, i)". You mentioned "sub()" in a previous post, what is it? I assume it is again a function with a "self" argument.
				 stripped = true
		   else --#if "str" is not equal to "self:sub(i, i)" and/or "stripped" is true, "newStr" is set to "newStr" + "self:sub(i, i)"
				 newStr = newStr .. self:sub(i, i)
		   end
	 end
	 return newStr --#once "i" is equal to "self:len()", the function returns the data contained in "newStr" to the program running.
end

--#usage
local str = "AA"
str = str:strip("A")

LBPHacker, on 25 December 2013 - 12:07 PM said:

Engineer, on 25 December 2013 - 11:22 AM said:

-snip-

Well, you can't declare local functions inside a table. And you'd have to modify the string metatable anyway.

Engineer, on 25 December 2013 - 03:37 PM said:

LBPHacker, on 25 December 2013 - 12:07 PM said:

Engineer, on 25 December 2013 - 11:22 AM said:

-snip-

Well, you can't declare local functions inside a table. And you'd have to modify the string metatable anyway.

Been long since I used Lua, as you might know :P/>

I would explain it, but I'm on a phone right now so it's a bit unhandy to explain.
As soon as I'm onto a computer I'm going to fix the code and try to explain it.

vennMessage = "Not implemented, showing canvas"
os.loadAPI("button")
m = peripheral.wrap("top")
m.clear()
sBox = "Search"
modem = peripheral.wrap("right")
buttonSet = 1
modem.open(0)
modem.open(2)
peripheral.call("computer_6", "reboot")
m.setBackgroundColor(1)
m.setTextColor(32768)
function checkMoodFigure(l1, l2, l3, n1)
   if l1 == "A" or l1 == "E" or l1 == "I" or l1 == "O" then
	  if l2 == "A" or l2 == "E" or l2 == "I" or l2 == "O" then
		 if l3 == "A" or l3 == "E" or l3 == "I" or l3 == "O" then
		    if n1 == 1 or n1 == 2 or n1 == 3 or n1 == 4 then
			   encryptRedNet("true", send, modem, 2, 1)
			   return true
		    else
			   encryptRedNet("false", send, modem, 2, 1)
			   return false
		    end
		 else
		    encryptRedNet("false", send, modem, 2, 1)
		    return false
		 end
	  else
		 encryptRedNet("false", send, modem, 2, 1)
		 return false
	  end
   else
	  encryptRedNet("false", send, modem, 2, 1)
	  return false
   end
end
function getSyllogism(letter1, number1)
   if number1 == 1 then
	  if letter1 == "O" then
		 return "Some M are not P"
	  elseif letter1 == "A" then
		 return "All M are P"
	  elseif letter1 == "E" then
		 return "No M are P"
	  elseif letter1 == "I" then
		 return "Some M are P"
	  end
   end
eof()--right here it says I am calling nil but if I change it to "end" it says eof expected
--if I put an "end" here it says eof expected as well
   if number1 == 2 then
	  if letter1 == "O" then
		 letter1Str = "Some P are not M"
	  elseif letter1 == "A" then
		 letter1Str = "All P are M"
	  elseif letter1 == "E" then
		 letter1Str = "No P are M"
	  elseif letter1 == "I" then
		 letter1Str = "Some P are M"
	  end
   end
eof()
eof()
   if number1 == 3 then
	  if letter1 == "O" then
		 letter1Str = "Some M are not P"
	  elseif letter1 == "A" then
		 letter1Str = "All M are P"
	  elseif letter1 == "E" then
		 letter1Str = "No M are P"
	  elseif letter1 == "I" then
		 letter1Str = "Some M are P"
	  end
   end
eof()
   if number1 == 4 then
	  if letter1 == "O" then
		 letter1Str = "Some P are not M"
	  elseif letter1 == "A" then
		 letter1Str = "All P are M"
	  elseif letter1 == "E" then
		 letter1Str = "No P are M"
	  elseif letter1 == "I" then
		 letter1Str = "Some P are M"
	  end
   end
eof()
eof()
function sBoxFix(sBoX)
   if sBoX == nil then
	  return "Search"
   else
	  return sBoX
   end
end
function heading2(text, row)
   w, h = m.getSize()
   m.setCursorPos((w-string.len(text))/2+1, row)
   m.write(text)
end
function encryptRedNet(message, sndRec, modem, to, from)
   if sndRec == "send" then
	  encMessage = textutils.serialize(message)
	  modem.transmit(to, from, encMessage)
	  return true
   elseif sndRec == "recive" then
	  decMessage = textutils.unserialize(message)
	  return decMessage
   end
end
function fillTable()
   button.setTable("A", a, 10,20,3,5)
   button.setTable("E", e, 22,32,3,5)
   button.setTable("I", i, 10,20,8,10)
   button.setTable("O", o, 22,32,8,10)
   button.screen()
   m.setBackgroundColor(1)
   m.setTextColor(32768)
end
function fillTable2()
   button.unsetTable("A")
   button.unsetTable("E")
   button.unsetTable("I")
   button.unsetTable("O")
   button.setTable("figure1", f, 10,20,3,5)
   button.setTable("figure2", g, 22,32,3,5)
   button.setTable("figure3", h, 10,20,8,10)
   button.setTable("figure4", j, 22,32,8,10)
   button.screen()
   m.setBackgroundColor(1)
   m.setTextColor(32768)
end
function fillTable3()
   button.unsetTable("figure1")
   button.unsetTable("figure2")
   button.unsetTable("figure3")
   button.unsetTable("figure4")
   button.setTable("Back", back, 10,20,8,10)
   button.setTable("Generate", Venn, 22,32,8,10)
   button.screen()
   m.setBackgroundColor(1)
   m.setTextColor(32768)
end
function unFillTable2()
   button.unsetTable("figure1")
   button.unsetTable("figure2")
   button.unsetTable("figure3")
   button.unsetTable("figure4")
   m.setBackgroundColor(1)
   m.setTextColor(32768)
end
function getClick()
   event234,side,x,y = os.pullEvent("monitor_touch")
   button.checkxy(x,y)
   return event234
end
function a()
   button.flash("A")
   encryptRedNet("A", "send", modem, 0, 0)
end
function e()
   button.flash("E")
   encryptRedNet("E", "send", modem, 0, 0)
end
function i()
   button.flash("I")
   encryptRedNet("I", "send", modem, 0, 0)
end
function o()
   button.flash("O")
   encryptRedNet("O", "send", modem, 0, 0)
end
function f()
   button.flash("figure1")
   encryptRedNet("1", "send", modem, 0, 0)
end
function g()
   button.flash("figure2")
   encryptRedNet("2", "send", modem, 0, 0)
end
function h()
   button.flash("figure3")
   encryptRedNet("3", "send", modem, 0, 0)
end
function j()
   button.flash("figure4")
   encryptRedNet("4", "send", modem, 0, 0)
end
function back()
   button.flash("Back")
   os.reboot()
end
function Venn()
   m.clear()
   m.setBackgroundColor(1)
   m.setTextColor(32768)
   button.heading(vennMessage)
   term.redirect(m)
   VennDiagramGraphic = paintutils.loadImage("canvas")
   paintutils.drawImage(VennDiagramGraphic, 1, 2)
   m.setBackgroundColor(1)
   m.setTextColor(32768)
   term.restore()
   m.setCursorPos(7, 9)
   m.write("S")
   m.setCursorPos(20, 9)
   m.write("M")
   m.setCursorPos(13, 14)
   m.write("P")
   while true do
	  event534 = os.pullEvent("monitor_touch")
	  if event534 == "monitor_touch" then
		 event534 = nil
		 os.reboot()
	  end
   end
end  
while true do
   button.heading(sBox)
   button.label(1,5,"Logic!")
   if buttonSet == 1 then
	  m.clear()
	  fillTable()
	  button.heading(sBox)
	  button.label(1,5,"Logic!")
	  m.setBackgroundColor(1)
	  m.setTextColor(32768)
   elseif buttonSet == 2 then
	  m.clear()
	  fillTable2()
	  button.heading(sBox)
	  button.label(1,5,"Logic!")
	  m.clear()
	  fillTable2()
	  button.heading(sBox)
	  button.label(1,5,"Logic!")
	  m.setBackgroundColor(1)
	  m.setTextColor(32768)
   elseif buttonSet == 3 then
	  m.clear()
	  fillTable3()
	  button.heading(sBox)
	  button.label(1,5,"Logic!")
	  m.setBackgroundColor(1)
	  m.setTextColor(32768)
   end
   button.screen()
   clickButton = getClick()
   if clickButton == "monitor_touch" then
	  event234 = nil
   event, side, chan, rchan, message, distance = os.pullEvent("modem_message")
   sSBox = encryptRedNet(message, "recive", modem, 0, 0)
   buttonSet = sSBox["bSet"]
   if sSBox["type"] == "string" then
	  sBox = sSBox["sent"]
	  sSBox = nil
	  m.setBackgroundColor(1)
	  m.setTextColor(32768)
   elseif sSBox["type"] == "number" then
	  m.clear()
	  fillTable2()
	  sBox = sSBox["sent"]
	  buttonSet = 2
	  sSBox = nil
	  m.setBackgroundColor(1)
	  m.setTextColor(32768)
   elseif sSBox["type"] == "table" then
	  m.clear()
	  m.setBackgroundColor(1)
	  m.setTextColor(32768)
	  sBox = sSBox["letterMood"].." - "..sSBox["numberFigure"]
	  button.heading(sBox)
	  button.label(1,5,"Logic!")
	  heading2("Computing...", 2)
	  VennDiagram = sSBox["letterMood"]..sSBox["numberFigure"]
	  sSBox = nil
	  os.sleep(2)
	  --encryptRedNet("compute", "send", modem, 0, 0)
	  m.setBackgroundColor(1)
	  m.setTextColor(32768)
   elseif sSBox["type"] == "compute" then
	  m.clear()
	  m.setBackgroundColor(1)
	  m.setTextColor(32768)
	  button.heading(sBox)
	  majPrem = sSBox["letterMood1"]
	  minPrem = sSBox["letterMood2"]
	  finCon = sSBox["letterMood3"]
	  numberFigure = sSBox["numberFigure"]
	  sBox = majPrem..minPrem..finCon.."-"..numberFigure
	  thisthat = {"gotThis!"}
	  encryptRedNet(thisthat, send, modem, 2, 1)
	  print(majPrem..minPrem..finCon..numberFigure)
	  button.heading(sBox)
	  button.label(1,5,"Logic!")
	  button.screen()
	  m.setBackgroundColor(1)
	  m.setTextColor(32768)
	  line2 = getSyllogism(majPrem, numberFigure)
	  print(line2)
	  line3 = getSyllogism(minPrem, numberFigure)
	  line4 = getSyllogism(finCon, numberFigure)
	  heading2(line2, 2)
	  --heading2(line3, 3)
	  --heading2(line4, 4)
   end --Line 380
end
end
eof()

something = something
if type(something) == string then
   print("YES")
else
   print("no")
end

if type(something) == "string" then
...

something = "Hello World!"
if type( something ) == "string" then -- Type returns a string and not a variable
	print("It was a string")
else
	print("Nope")
end

error(string, number?)

function testError(level)
   error("I am an error!", level)
end
testError(1) returns myAwesomeFile:4:
testError(2) returns testError:1: