-- zero: word to use for value '0' (nil to use default)
-- use_one (boolean): false: 2+1/2 → "two and a half"; true: "two and one-half"
local function _numeral_to_english(num, numerator, denominator, capitalize, use_and, hyphenate, ordinal, plural, links, negative_word, round, zero, use_one)
if not negative_word then
if use_and then
-- TODO Should 'minus' be used when do not have sp=us?
-- If so, need to update testcases, and need to fix "minus zero".
-- negative_word = 'minus'
negative_word = 'negative'
else
negative_word = 'negative'
end
end
local status, fraction_text = fraction_to_english(num, numerator, denominator, not use_and, negative_word, use_one)
if status == 'unsupported' then
return nil
end
if status == 'finished' then
-- Input is a fraction with no whole number.
-- Hack to avoid executing stuff that depends on num being a number.
local s = fraction_text
if hyphenate then s = s:gsub("%s", "-") end
if capitalize then s = s:gsub("^%l", string.upper) end
return s
end
num = scientific_notation_to_decimal(num)
if round and round ~= '' then
if round ~= 'on' and round ~= 'up' and round ~= 'down' then
error("Invalid rounding mode")
end
num = round_for_english(num, round)
end  
-- Separate into negative sign, num (digits before decimal), decimal_places (digits after decimal)
local MINUS = '−' -- Unicode U+2212 MINUS SIGN (may be in values from Module:Convert)
if num:sub(1, #MINUS) == MINUS then
num = '-' .. num:sub(#MINUS + 1) -- replace MINUS with '-'
elseif num:sub(1, 1) == '+' then
num = num:sub(2) -- ignore any '+'
end
local negative = num:find("^%-")
local decimal_places, subs = num:gsub("^%-?%d*%.(%d+)$", "%1")
if subs == 0 then decimal_places = nil end
num, subs = num:gsub("^%-?(%d*)%.?%d*$", "%1")
if num == '' and decimal_places then num = '0' end
if subs == 0 or num == '' then error("Invalid decimal numeral") end  
-- For each group of 3 digits except the last one, print with appropriate group name (e.g. million)
local s = ''
while #num > 3 do
if s ~= '' then s = s .. ' ' end
local group_num = math.floor((#num - 1) / 3)
local group = groups[group_num]
local group_digits = #num - group_num*3
s = s .. numeral_to_english_less_1000(num:sub(1, group_digits), false, false, false, zero) .. ' '
if links and (((links == 'on' and group_num >= 3) or links:find(group)) and group_num <= 13) then
s = s .. * .. group .. *
else
s = s .. group
end
num = num:sub(1 + group_digits)
num = num:gsub("^0*", "") -- Trim leading zeros
end  
-- Handle final three digits of integer part
if s ~= * and num ~= * then
if #num <= 2 and use_and then
s = s .. ' and '
else
s = s .. ' '
end
end
if s == * or num ~= * then
s = s .. numeral_to_english_less_1000(num, use_and, ordinal, plural, zero)
elseif ordinal or plural then
-- Round numbers like "one million" take standard suffixes for ordinal/plural
s = s .. standard_suffix(ordinal, plural)
end  
-- For decimal places (if any) output "point" followed by spelling out digit by digit
if decimal_places then
s = s .. ' point'
for i = 1, #decimal_places do
s = s .. ' ' .. ones_position[tonumber(decimal_places:sub(i,i))]
end
end  
s = s:gsub("^%s*(.-)%s*$", "%1") -- Trim whitespace
if ordinal and plural then s = s .. 's' end -- s suffix works for all ordinals
if negative and s ~= zero then s = negative_word .. ' ' .. s end
s = s:gsub("negative zero", "zero")
s = s .. fraction_text
if hyphenate then s = s:gsub("%s", "-") end
if capitalize then s = s:gsub("^%l", string.upper) end
return s
end  
local function _numeral_to_english2(args)
local num = args.num  
if (not tonumber(num)) then
num = num:gsub("^%s*(.-)%s*$", "%1") -- Trim whitespace
num = num:gsub(",", "") -- Remove commas
num = num:gsub("^<span[^<>]*></span>", "") -- Generated by Template:age
if num ~= '' then -- a fraction may have an empty whole number
if not num:find("^%-?%d*%.?%d*%-?[Ee]?[+%-]?%d*$") then
-- Input not in a valid format, try to pass it through #expr to see
-- if that produces a number (e.g. "3 + 5" will become "8").
num = mw.getCurrentFrame:preprocess('')
end
end
end  
-- Pass args from to helper function
return _numeral_to_english(
num,
args['numerator'],
args['denominator'],
args['capitalize'],
args['use_and'],
args['hyphenate'],
args['ordinal'],
args['plural'],
args['links'],
args['negative_word'],
args['round'],
args['zero'],
args['use_one']
) or ''
end  
local p = { -- Functions that can be called from another module
roman_to_numeral = roman_to_numeral,
spell_number = _numeral_to_english,
spell_number2 = _numeral_to_english2,
english_to_ordinal = english_to_ordinal,
english_to_numeral = english_to_numeral,
}  
function p._roman_to_numeral -- Callable via
return roman_to_numeral(.args[1])
end  
function p._english_to_ordinal -- callable via
return english_to_ordinal(.args[1])
end  
function p._english_to_numeral -- callable via
return english_to_numeral(.args[1])
end  
function p.numeral_to_english
local args = .args
local num = args[1]
num = num:gsub("^%s*(.-)%s*$", "%1") -- Trim whitespace
num = num:gsub(",", "") -- Remove commas
num = num:gsub("^<span[^<>]*></span>", "") -- Generated by Template:age
if num ~= '' then -- a fraction may have an empty whole number
if not num:find("^%-?%d*%.?%d*%-?[Ee]?[+%-]?%d*$") then
-- Input not in a valid format, try to pass it through #expr to see
-- if that produces a number (e.g. "3 + 5" will become "8").
num = :preprocess('')
end
end  
-- Pass args from to helper function
return _numeral_to_english(
num,
args['numerator'],
args['denominator'],
args['case'] == 'U' or args['case'] == 'u',
args['sp'] ~= 'us',
args['adj'] == 'on',
args['ord'] == 'on',
args['pl'] == 'on',
args['lk'],
args['negative'],
args['round'],
args['zero'],
args['one'] == 'one' -- experiment: using '|one=one' makes fraction 2+1/2 give "two and one-half" instead of "two and a half"
) or ''
end  
---- recursive function for p.decToHex
local function decToHexDigit(dec)
local dig = {"0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F"}
local div = math.floor(dec/16)
local mod = dec-(16*div)
if div >= 1 then return decToHexDigit(div)..dig[mod+1] else return dig[mod+1] end
end -- I think this is supposed to be done with a tail call but first I want something that works at all  
---- finds all the decimal numbers in the input text and hexes each of them
function p.decToHex
local args=.args
local parent=.getParent
local pargs={}
if parent then pargs=parent.args end
local text=args[1] or pargs[1] or ""
local minlength=args.minlength or pargs.minlength or 1
minlength=tonumber(minlength)
local prowl=mw.ustring.gmatch(text,"(.-)(%d+)")
local output=""
repeat
local chaff,dec=prowl
if not(dec) then break end
local hex=decToHexDigit(dec)
while (mw.ustring.len(hex)<minlength) do hex="0"..hex end
output=output..chaff..hex
until false
local chaff=mw.ustring.match(text,"(%D+)$") or ""
return output..chaff
end  
return p