Module:Format ISBN

data = require("Module:Format ISBN/data") local p = {}

function errMsg(s) return ' Can&#x27;t format invalid ISBN: '..s..' ' end

function p.formatISBN(s, link) if link == nil then link = true end if (not s) or (#s == 0) then return '' end s = tostring(s) -- some other module may have fed us an unquoted number local test = require("Module:Check isxn").check_isbn({ args = { s, error = errMsg(s) }}) if #test > 0 then return test end local s = string.gsub(s, "[^%dX]", "") if #s == 10 then s = string.sub("978"..s, 1, 12) local n = 0 for i=1,12 do n = n + tonumber(string.sub(s,i,i)) * (3 - (i % 2) * 2) end s = s..((10-(n%10))%10) end for i=1,#data do		if s <= data[i][1] then local a = 4 local r = { string.sub(s,1,3) } for j=1,3 do				local n = data[i][2][j] r[j+1] = string.sub(s, a, a+n-1) a = a + n			end r[5] = string.sub(s,13) local sFmt = table.concat(r, "-") if link then return ..sFmt.. else return sFmt end end end return s -- should never actually be reached end

function p.main(frame) local args = require("Module:Arguments").getArgs(frame) local isbn = args[1] local link = string.sub(string.lower(args["link"] or "yes"), 1, 1) ~= "n" return p.formatISBN(isbn, link) end

return p