Module:BaseConvert

-- -- Converts numbers to a specified base between 2 and 36, for use in -- templates such as, undefined, undefined, etc. -- -- from - the base of the input. Defaults to 10 (or 16 if the input has a --  leading '0x'). Note that bases other than 10 are not supported if the --  input has a fractional part. -- precision - number of digits to be rendered after the radix point. Trailing --  zeros will be added if needed. If not specified, however many digits are --  needed will be shown, up to 10. -- width - minimum number of digits to be rendered before the radix point. --  Leading zeros will be added if needed. -- default - Value to return if n is empty or non-numeric. Defaults to the --  value of n. -- prefix/suffix - wikitext to add before/after the returned result. Will not --  be added if n is empty or non-numeric. For example, you might use a --  prefix of '0x' when converting to hex, or a suffix of '8' when --  converting to octal. --

local p = {}

local digits = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'

function normalizeFullWidthChars(s) return mw.ustring.gsub(s, '[！-～]', function(s)        return mw.ustring.char(mw.ustring.codepoint(s, 1) - 0xFEE0)     end) end

function p._convert(n, base, from, precision, width, default, prefix, suffix) n = '' .. n  -- convert to a string -- strip off any leading '0x' (unless x is a valid digit in the input base) from = tonumber(from) if not from or from < 34 then local c       n, c = n:gsub('^(-?)0[Xx]', '%1') if c > 0 and not from then from = 16 end end

-- check for a negative sign. Do this while the input is still in string form, -- because tonumber doesn't support negative numbers in non-10 bases. local sign = '' local c   n, c = n:gsub('^-', '') if c > 0 then sign = '-' end -- replace any full-width Unicode characters in the string with their ASCII equivalents n = normalizeFullWidthChars(n) -- handle scientific notation with whitespace around the 'e' e.g. '5 e7' n = n:gsub('%s*[eE]%s*', 'e') from = from or 10 local num = tonumber(n, from) base = tonumber(base) precision = tonumber(precision) width = tonumber(width) if not num or not base then return default or n end local i, f = math.modf(num)

local t = {} repeat local d = (i % base) + 1 i = math.floor(i / base) table.insert(t, 1, digits:sub(d, d)) until i == 0 while #t < (width or 0) do       table.insert(t, 1, '0') end local intPart = table.concat(t, '') -- compute the fractional part local tf = {} while f > 0 and #tf < (precision or 10) do       f = f * base i, f = math.modf(f) table.insert(tf, digits:sub(i + 1, i + 1)) end -- add trailing zeros if needed if precision and #tf < precision then for i = 1, precision - #tf do           table.insert(tf, '0') end end

fracPart = table.concat(tf, '') -- remove trailing zeros if not needed if not precision then fracPart = fracPart:gsub('0*$', '') end -- add the radix point if needed if #fracPart > 0 then fracPart = '.' .. fracPart end return (prefix or '') .. sign .. intPart .. fracPart .. (suffix or '') end

function p.convert(frame) local n = frame.args.n   local base = frame.args.base local from = frame.args.from local precision = frame.args.precision local width = frame.args.width local default = frame.args.default local prefix = frame.args.prefix local suffix = frame.args.suffix return p._convert(n, base, from, precision, width, default, prefix, suffix) end

return p