lua string.split

The string.split function in Lua is not a built-in function, but it can be implemented using the following code:

function string.split(inputstr, sep)
    if sep == nil then
        sep = "%s"
    end
    local t = {}
    for str in string.gmatch(inputstr, "([^"..sep.."]+)") do
        table.insert(t, str)
    end
    return t
end

Let's break down the steps of this code:

1. The function string.split is defined, which takes two parameters: inputstr and sep.
2. Inside the function, there is a check to see if the sep parameter is nil. If it is, then the default value is set to "%s", which represents any whitespace character.
3. A table t is created to store the split strings.
4. A for loop is used to iterate over the strings that match the pattern ([^"..sep.."]+) in the inputstr using the string.gmatch function.
5. In each iteration of the loop, the matched string str is inserted into the table t using the table.insert function.
6. Finally, the table t is returned, which contains all the split strings.

That's how the string.split function works in Lua. It takes a string and a separator, and returns a table containing the split strings.