# เกณฑ์สำหรับวัด:Roman

คู่มือการใช้งานมอดูล[สร้าง]
```-- This module implements {{Roman}}.

local p = {}

-- This function implements the {{overline}} template.
local function overline( s )
return mw.ustring.format( '<span style="text-decoration:overline;">%s</span>', s )
end

-- Gets the Roman numerals for a given numeral table. Returns both the string of
-- numerals and the value of the number after it is finished being processed.
local function getLetters( num, t )
local ret = {}
for _, v in ipairs( t ) do
local val, letter = unpack( v )
while num >= val do
num = num - val
table.insert( ret, letter )
end
end
return table.concat( ret ), num
end

-- The main control flow of the module.
local function _main( args )
-- Get input and exit displaying nothing if the input is bad.
local num = tonumber( args[ 1 ] )
if not num or num < 1 or num == math.huge then
return
end
num = math.floor( num )

-- Return a message for numbers too big to be expressed in Roman numerals.
if num >= 5000000 then
return args[ 2 ] or 'N/A'
end

local ret = ''
-- Find the Roman numerals for the large part of numbers 5000 and bigger.
-- The if statement is not strictly necessary, but makes the algorithm
-- more efficient for smaller numbers.
if num >= 5000 then
local bigRomans = {
{ 1000000, 'M' },
{ 900000, 'CM' }, { 500000, 'D' }, { 400000, 'CD' }, { 100000, 'C' },
{ 90000, 'XC' }, { 50000, 'L' }, { 40000, 'XL' }, { 10000, 'X' },
{ 5000, 'V' }
}
local bigLetters
bigLetters, num = getLetters( num, bigRomans )
ret = overline( bigLetters )
end

-- Find the Roman numerals for numbers 4999 or less.
local smallRomans = {
{1000, "M"},
{900, "CM"}, {500, "D"}, {400, "CD"}, {100, "C"},
{90, "XC"}, {50, "L"}, {40, "XL"}, {10, "X"},
{9, "IX"}, {5, "V"}, {4, "IV"}, {1, "I"}
}
local smallLetters = getLetters( num, smallRomans )
ret = ret .. smallLetters

return ret
end

function p.main( frame )
-- If called via #invoke, use the args passed into the invoking
-- template, or the args passed to #invoke if any exist. Otherwise
-- assume args are being passed directly in from the debug console
-- or from another Lua module.
local origArgs
if frame == mw.getCurrentFrame() then
origArgs = frame:getParent().args
for k, v in pairs( frame.args ) do
origArgs = frame.args
break
end
else
origArgs = frame
end
-- Trim whitespace and remove blank arguments.
local args = {}
for k, v in pairs( origArgs ) do
if type( v ) == 'string' then
v = mw.text.trim( v )
end
if v ~= '' then
args[k] = v
end
end
return _main( args )
end

return p
```