Gammon Forum

function WordtoNum (str)
	local P, V, Cf, C, Cg, Cc = lpeg.P, lpeg.V, lpeg.Cf, lpeg.C, lpeg.Cg, lpeg.Cc
	lpeg.locale(lpeg)
	local numvalues = {  one = 1, two = 2, three = 3, four = 4, five = 5,
				six = 6, seven = 7, eight = 8, nine= 9, ten = 10,
				eleven = 11, twelve = 12, thirteen = 13, fourteen = 14, fifteen = 15,
				sixteen = 16, seventeen = 17, eighteen = 18, nineteen = 19, twenty = 20,
				thirty = 30, forty = 40, fifty = 50, sixty = 60, seventy = 70, eighty = 80,
				ninety = 90, hundred = 10^2,
				thousand = 10^3,
				million = 10^6,
				billion = 10^9,
				trillion = 10^12,
				quadrillion = 10^15,
				--blah blah
				}

	local ndigit = P"twenty" + P"thirty" + P"forty" + P"fifty" + P"sixty" + P"seventy" + P"eighty" + P"ninety" +
			P'hundred' +
			P"ten" + P"eleven" + P"twelve" + P"thirteen" + P"fourteen" + P"fifteen" +
			P"sixteen" + P"seventeen" + P"eighteen" + P"nineteen" +
			P"one" + P"two" + P"three" + P"four" + P"five" + P"six" + P"seven" + P"eight" + P"nine"


	local powers =   P'vigintillion' + P'novemdecillion' + P'octodecillion' + P'septendecillion' +
				P'sexdecillion' + P'quindecillion' + P'quattuordecillion' + P'tredecillion' +
				P'duodecillion' + P'undecillion' + P'decillion' + P'nonillion' + P'octillion' +
				P'septillion' + P'sextillion' + P'quintillion' + P'quadrillion' + P'trillion' +
				P'billion' + P'million' + P'thousand'

	local function SumVals (seed, ...)
		local cypher = {...}
		local tmp = 0

		for x = 1, #cypher do
			if numvalues[cypher[x]] == 100 then
				if tmp == 0 then
					tmp = 100
				else
					tmp = tmp * 100
				end
			elseif powers:match(cypher[x] or "") then
				tmp = tmp * numvalues[cypher[x]]
			else
				tmp = tmp + numvalues[cypher[x]]
			end
		end
		return seed + tmp
	end

	local cypher = Cg( (C(ndigit) * lpeg.space^-1)^1 * ((C(powers) * lpeg.space^-1) + P(0)) )
	local number = Cf(Cc(0) * cypher^1, SumVals)

	return number:match(str)
end

[string "Immediate"]:41: bad argument #1 to 'match' (string expected, got nil)
stack traceback:
	[C]: in function 'match'
	[string "Immediate"]:41: in function <[string "Immediate"]:30>
	[C]: in function 'match'
	[string "Immediate"]:53: in function 'WordtoNum'
	[string "Immediate"]:56: in main chunk

[string "Immediate"]:44: attempt to perform arithmetic on field '?' (a nil value)
stack traceback:
	[string "Immediate"]:44: in function <[string "Immediate"]:30>
	[C]: in function 'match'
	[string "Immediate"]:53: in function 'WordtoNum'
	[string "Immediate"]:57: in main chunk

for i=...
   cypher[x]

print (string.rep ("-", 75))

for i = 1, 5000 do
  local s = ""
  for i = 1, math.floor (MtRand () * 10 + 1) do
    s = s .. math.floor (MtRand () * 10)
  end -- for
  
  print ("Converting: '" .. s .. "'")
  local words = assert (convert_numbers_to_words (s))
  print ("Result =", words)

  n2 = WordtoNum (words)
  print ("LPEG result was:", n2)

  assert (tostring (n2) == string.gsub (s, "^0+", ""), "LPEG conversion failed!")
end -- for