Find And Replace API [WIP]

function findAndReplace(string,data,replacedata)
if not type(string) == "string" and type(data) == "string" and type(replacedata) == "string" then error("All 3 vars must be strings") end
while true do
pos = string.find(string,data)
if pos==nil then break end
j=j or true
string=string..""
local offset=string.len(string)+string.len(replacedata)
offset=offset-string.len(data)
local lastpos=pos + string.len(replacedata)
string = string.sub(string, 1, pos-1)..replacedata..string.sub(string, lastpos,string.len(string)+offset)
end
return j and string
end