Lua

Lua is a scripting Programming Language which is designed to be simple and can be easily embedded. It runs on a Virtual Machine. Variables are global by default, so local is used to declare a variable as local to the current scope. It starts index at 1 contrary to most programming languages.

There are eight types:

• nil
• boolean
• number
• string
• userdata (used to represent C data structures, or blocks of raw memory)
• function
• thread (used for coroutines)
• table (an associative array, and the sole data structure in Lua)

Binary search written in Lua:

function binary_search(array, value)
    local low = 1
    local high = #array -- # is the length operator

    while low <= high do
        -- library functions are accessed via the global table
        local mid = math.floor((low + high) / 2)
        local mid_value = array[mid]

        if mid_value < value then
            low = mid + 1
        elseif mid_value > value then
            high = mid - 1
        else
            return mid
        end
    end

    return nil
end

res = binary_search({2, 4, 6, 8, 9}, 6)
print(res)

3

• Lua: The Little Language That Could