Module:Format price

local p = {} local names = { "million", "billion", "trillion", "quadrillion", "quintillion", "sextillion", "septillion", "octillion" }

-- two_decimals: boolean, whether to forbid a 1 d.p. result, so 2 becomes "2", --				 2.1 "2.10", and 2.123 "2.123" function p.decimal(val, length, two_decimals) local precision = math.max(0, math.ceil(length - 1 - math.log10(val))) if two_decimals and precision == 1 then precision = 2 end local result = ("%%.%uf"):format(precision):format(val) if two_decimals then result = result:gsub('%.0*$', ''):gsub('(%.[0-9][0-9][0-9]-)0+$', '%1') else result = result:gsub('%.?0*$', '') end result = mw.text.split(result, '%.') result[1] = result[1]:reverse:gsub('[0-9][0-9][0-9]', '%0,'):reverse:gsub('^,','') return table.concat(result, '.') end

function p.format(val, precision) local scale = math.floor(math.log10(val) / 3) - 1 if scale > 0 then scale = math.min(scale, #names) val = val / math.pow(10, 3 * (1 + scale)) return p.decimal(val, 3) .. '\194\160' .. names[scale] end

if precision <= 0 then val = math.floor(val / math.pow(10, -precision) + 0.5) val = val * math.pow(10, -precision) end return p.decimal(val, precision + 1, true) end

p[''] = function(frame) local val = tonumber(frame.args[1]) if not val or val < 0 then error('Format price error: cannot parse value "' .. (frame.args[1] or '') .. '"') end return p.format(val, tonumber(frame.args[2]) or 2) end

return p