Lua tips for TouchOSC scripting (Lua 5.1)

lua_tips_touchosc.md

• You can omit parenthesis in function calls, if your argument is a string or a table

myFunc"hello"
myFunc{1,2,3}

• Variable number of function arguments

function myFunc(...)
  local args = {...}
end

Example: Join n number of tables

function joinTables(...)
  local tables = {...}; local result = {};
  for _,t in pairs(tables) do
    for k,v in pairs(t) do table.insert(result,v) end
  end
  return result
end

--usage:
local joinedTables = joinTables({1,2,3},{4,5,6})
--output: {1,2,3,4,5,6}

• Extract part of a table into a new table

local partialTable = {table.unpack(myTable, from_index, to_index)}

• Assign multiple variables in one line

local x,y,z = 1,2,3

• Return multiple values from a function

function multipleReturns()
  local a = "foo"
  local b = "bar"
  return a,b
end

local r1,r2 = multipleReturns()
-- r1 = "foo", r2 = "bar"