A simple pattern/filter generator. Could be useful for a blacklist of words or something, probably.

Case Insensitive Pattern Generator.lua

function case_insensitive_pattern(pattern)
	local p = pattern:gsub("(%%?)(.)", function(percent, letter) -- match regex
		if percent ~= "" or not letter:match("%a") then
			-- if % is matched or 'letter' is not a letter
			return percent .. letter
		else
			return string.format("[%s%s]", letter:upper(), letter:lower())
		end
	end)
	return p
end

--[[
EXAMPLE
=======
pattern = case_insensitive_pattern("heck")
print(("heck HeCk HECK HECKIN"):gsub(pattern, "****")) --> **** **** **** ****IN
]]--

Really only useful if you're making like a chat filter or something