Lua pattern replace uppercase letters

Question

I need a special Lua pattern that takes all the uppercase letters in a string, and replaces them with a space and the respective lowercase letter;

TestStringOne => test string one
this isA TestString => this is a test string

Can it be done?

Answer 1

Assuming only ASCII is used, this works:

function lowercase(str)
  return (str:gsub("%u", function(c) return ' ' .. c:lower() end))
end

print(lowercase("TestStringOne"))
print(lowercase("this isA TestString"))