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-- Convert a value from one unit of measurement to another.-- Example: {{convert|123|lb|kg}} --> 123 pounds (56 kg)-- See [[:en:Template:Convert/Transwiki guide]] if copying to another wiki.local MINUS = '−'  -- Unicode U+2212 MINUS SIGN (UTF-8: e2 88 92)local abs = math.abslocal floor = math.floorlocal format = string.formatlocal log10 = math.log10local ustring = mw.ustringlocal ulen = ustring.lenlocal usub = ustring.sub-- Configuration options to keep magic values in one location.-- Conversion data and message text are defined in separate modules.local config, maxsigfiglocal numdot  -- must be '.' or ',' or a character which works in a regexlocal numsep, numsep_remove, numsep_remove2local data_code, all_unitslocal text_codelocal varname        -- can be a code to use variable names that depend on valuelocal from_en_table  -- to translate an output string of en digits to local languagelocal to_en_table    -- to translate an input string of digits in local language to en-- Use translation_table in convert/text to change the following.local en_default           -- true uses lang=en unless convert has lang=local or local digitslocal group_method = 3     -- code for how many digits are in a grouplocal per_word = 'per'     -- for units like "liters per kilometer"local plural_suffix = 's'  -- only other useful value is probably '' to disable plural unit nameslocal omitsep              -- true to omit separator before local symbol/name-- All units should be defined in the data module. However, to cater for quick changes-- and experiments, any unknown unit is looked up in an extra data module, if it exists.-- That module would be transcluded in only a small number of pages, so there should be-- little server overhead from making changes, and changes should propagate quickly.local extra_module  -- name of module with extra unitslocal extra_units   -- nil or table of extra units from extra_module-- Some options in the invoking template can set variables used later in the module.local currency_text  -- for a user-defined currency symbol: {{convert|12|$/ha|$=€}} (euro replaces dollar)local function from_en(text)	-- Input is a string representing a number in en digits with '.' decimal mark,	-- without digit grouping (which is done just after calling this).	-- Return the translation of the string with numdot and digits in local language.	if numdot ~= '.' then		text = text:gsub('%.', numdot)	end	if from_en_table then		text = text:gsub('%d', from_en_table)	end	return textendlocal function to_en(text)	-- Input is a string representing a number in the local language with	-- an optional numdot decimal mark and numsep digit grouping.	-- Return the translation of the string with '.' mark and en digits,	-- and no separators (they have to be removed here to handle cases like	-- numsep = '.' and numdot = ',' with input "1.234.567,8").	if to_en_table then		text = ustring.gsub(text, '%d', to_en_table)	end	if numsep_remove then		text = text:gsub(numsep_remove, '')	end	if numsep_remove2 then		text = text:gsub(numsep_remove2, '')	end	if numdot ~= '.' then		text = text:gsub(numdot, '.')	end	return textendlocal function decimal_mark(text)	-- Return ',' if text probably is using comma for decimal mark, or has no decimal mark.	-- Return '.' if text probably is using dot for decimal mark.	-- Otherwise return nothing (decimal mark not known).	if not text:find('[.,]') then return ',' end	text = text:gsub('^%-', ''):gsub('%+%d+/%d+$', ''):gsub('[Ee]%-?%d+$', '')	local decimal =		text:match('^0?([.,])%d+$') or		text:match('%d([.,])%d?%d?$') or		text:match('%d([.,])%d%d%d%d+$')	if decimal then return decimal end	if text:match('%.%d+%.') then return ',' end	if text:match('%,%d+,') then return '.' endendlocal add_warning, with_separator  -- forward declarationslocal function to_en_with_check(text, parms)	-- Version of to_en() for a wiki using numdot = ',' and numsep = '.' to check	-- text (an input number as a string) which might have been copied from enwiki.	-- For example, in '1.234' the '.' could be a decimal mark or a group separator.	-- From viwiki.	if to_en_table then		text = ustring.gsub(text, '%d', to_en_table)	end	if decimal_mark(text) == '.' then		local original = text		text = text:gsub(',', '')  -- for example, interpret "1,234.5" as an enwiki value		if parms then			add_warning(parms, 0, 'cvt_enwiki_num', original, with_separator({}, text))		end	else		if numsep_remove then			text = text:gsub(numsep_remove, '')		end		if numsep_remove2 then			text = text:gsub(numsep_remove2, '')		end		if numdot ~= '.' then			text = text:gsub(numdot, '.')		end	end	return textendlocal function omit_separator(id)	-- Return true if there should be no separator before id (a unit symbol or name).	-- For zhwiki, there should be no separator if id uses local characters.	-- The following kludge should be a sufficient test.	if omitsep then		if id:sub(1, 2) == '-{' then  -- for "-{...}-" content language variant			return true		end		if id:byte() > 127 then			local first = usub(id, 1, 1)			if first ~= 'Å' and first ~= '°' and first ~= 'µ' then				return true			end		end	end	return id:sub(1, 1) == '/'  -- no separator before units like "/ha"endlocal spell_module  -- name of module that can spell numberslocal speller       -- function from that module to handle spelling (set if needed)local wikidata_module, wikidata_data_module  -- names of Wikidata moduleslocal wikidata_code, wikidata_data  -- exported tables from those modules (set if needed)local function set_config(args)	-- Set configuration options from template #invoke or defaults.	config = args	maxsigfig = config.maxsigfig or 14  -- maximum number of significant figures	local data_module, text_module	local sandbox = config.sandbox and ('/' .. config.sandbox) or ''	data_module = "Module:Convert/data" .. sandbox	text_module = "Module:Convert/text" .. sandbox	extra_module = "Module:Convert/extra" .. sandbox	wikidata_module = "Module:Convert/wikidata" .. sandbox	wikidata_data_module = "Module:Convert/wikidata/data" .. sandbox	spell_module = "Module:ConvertNumeric"	data_code = mw.loadData(data_module)	text_code = mw.loadData(text_module)	all_units = data_code.all_units	local translation = text_code.translation_table	if translation then		numdot = translation.numdot		numsep = translation.numsep		if numdot == ',' and numsep == '.' then			if text_code.all_messages.cvt_enwiki_num then				to_en = to_en_with_check			end		end		if translation.group then			group_method = translation.group		end		if translation.per_word then			per_word = translation.per_word		end		if translation.plural_suffix then			plural_suffix = translation.plural_suffix		end		varname = translation.varname		from_en_table = translation.from_en		local use_workaround = true		if use_workaround then			-- 2013-07-05 workaround bug by making a copy of the required table.			-- mw.ustring.gsub fails with a table (to_en_table) as the replacement,			-- if the table is accessed via mw.loadData.			local source = translation.to_en			if source then				to_en_table = {}				for k, v in pairs(source) do					to_en_table[k] = v				end			end		else			to_en_table = translation.to_en		end		if translation.lang == 'en default' then			en_default = true  -- for hiwiki		end		omitsep = translation.omitsep  -- for zhwiki	end	numdot = config.numdot or numdot or '.'  -- decimal mark before fractional digits	numsep = config.numsep or numsep or ','  -- group separator for numbers	-- numsep should be ',' or '.' or '' or '&nbsp;' or a Unicode character.	-- numsep_remove must work in a regex to identify separators to be removed.	if numsep ~= '' then		numsep_remove = (numsep == '.') and '%.' or numsep	end	if numsep ~= ',' and numdot ~= ',' then		numsep_remove2 = ','  -- so numbers copied from enwiki will work	endendlocal function collection()	-- Return a table to hold items.	return {		n = 0,		add = function (self, item)			self.n = self.n + 1			self[self.n] = item		end,	}endlocal function divide(numerator, denominator)	-- Return integers quotient, remainder resulting from dividing the two	-- given numbers, which should be unsigned integers.	local quotient, remainder = floor(numerator / denominator), numerator % denominator	if not (0 <= remainder and remainder < denominator) then		-- Floating point limits may need this, as in {{convert|160.02|Ym|ydftin}}.		remainder = 0	end	return quotient, remainderendlocal function split(text, delimiter)	-- Return a numbered table with fields from splitting text.	-- The delimiter is used in a regex without escaping (for example, '.' would fail).	-- Each field has any leading/trailing whitespace removed.	local t = {}	text = text .. delimiter  -- to get last item	for item in text:gmatch('%s*(.-)%s*' .. delimiter) do		table.insert(t, item)	end	return tendlocal function strip(text)	-- If text is a string, return its content with no leading/trailing	-- whitespace. Otherwise return nil (a nil argument gives a nil result).	if type(text) == 'string' then		return text:match("^%s*(.-)%s*$")	endendlocal function table_len(t)	-- Return length (<100) of a numbered table to replace #t which is	-- documented to not work if t is accessed via mw.loadData().	for i = 1, 100 do		if t[i] == nil then			return i - 1		end	endendlocal function wanted_category(catkey, catsort, want_warning)	-- Return message category if it is wanted in current namespace,	-- otherwise return ''.	local cat	local title = mw.title.getCurrentTitle()	if title then		local nsdefault = '0'  -- default namespace: '0' = article; '0,10' = article and template		local namespace = title.namespace		for _, v in ipairs(split(config.nscat or nsdefault, ',')) do			if namespace == tonumber(v) then				cat = text_code.all_categories[want_warning and 'warning' or catkey]				if catsort and catsort ~= '' and cat:sub(-2) == ']]' then					cat = cat:sub(1, -3) .. '|' .. mw.text.nowiki(usub(catsort, 1, 20)) .. ']]'				end				break			end		end	end	return cat or ''endlocal function message(parms, mcode, is_warning)	-- Return wikitext for an error message, including category if specified	-- for the message type.	-- mcode = numbered table specifying the message:	--    mcode[1] = 'cvt_xxx' (string used as a key to get message info)	--    mcode[2] = 'parm1' (string to replace '$1' if any in message)	--    mcode[3] = 'parm2' (string to replace '$2' if any in message)	--    mcode[4] = 'parm3' (string to replace '$3' if any in message)	local msg	if type(mcode) == 'table' then		if mcode[1] == 'cvt_no_output' then			-- Some errors should cause convert to output an empty string,			-- for example, for an optional field in an infobox.			return ''		end		msg = text_code.all_messages[mcode[1]]	end	parms.have_problem = true	local function subparm(fmt, ...)		local rep = {}		for i, v in ipairs({...}) do			rep['$' .. i] = v		end		return (fmt:gsub('$%d+', rep))	end	if msg then		local parts = {}		local regex, replace = msg.regex, msg.replace		for i = 1, 3 do			local limit = 40			local s = mcode[i + 1]			if s then				if regex and replace then					s = s:gsub(regex, replace)					limit = nil  -- allow long "should be" messages				end				-- Escape user input so it does not break the message.				-- To avoid tags (like {{convert|1<math>23</math>|m}}) breaking				-- the mouseover title, any strip marker starting with char(127) is				-- replaced with '...' (text not needing i18n).				local append				local pos = s:find(string.char(127), 1, true)				if pos then					append = '...'					s = s:sub(1, pos - 1)				end				if limit and ulen(s) > limit then					s = usub(s, 1, limit)					append = '...'				end				s = mw.text.nowiki(s) .. (append or '')			else				s = '?'			end			parts['$' .. i] = s		end		local function ispreview()			-- Return true if a prominent message should be shown.			if parms.test == 'preview' or parms.test == 'nopreview' then				-- For testing, can preview a real message or simulate a preview				-- when running automated tests.				return parms.test == 'preview'			end			local success, revid = pcall(function ()				return (parms.frame):preprocess('{{REVISIONID}}') end)			return success and (revid == '')		end		local want_warning = is_warning and			not config.warnings and  -- show unobtrusive warnings if config.warnings not configured			not msg.nowarn           -- but use msg settings, not standard warning, if specified		local title = string.gsub(msg[1] or 'Missing message', '$%d+', parts)		local text = want_warning and '*' or msg[2] or 'Missing message'		local cat = wanted_category(msg[3], mcode[2], want_warning)		local anchor = msg[4] or ''		local fmtkey = ispreview() and 'cvt_format_preview' or			(want_warning and 'cvt_format2' or msg.format or 'cvt_format')		local fmt = text_code.all_messages[fmtkey] or 'convert: bug'		return subparm(fmt, title:gsub('"', '&quot;'), text, cat, anchor)	end	return 'Convert internal error: unknown message'endfunction add_warning(parms, level, key, text1, text2)  -- for forward declaration above	-- If enabled, add a warning that will be displayed after the convert result.	-- A higher level is more verbose: more kinds of warnings are displayed.	-- To reduce output noise, only the first warning is displayed.	if level <= (tonumber(config.warnings) or 1) then		if parms.warnings == nil then			parms.warnings = message(parms, { key, text1, text2 }, true)		end	endendlocal function spell_number(parms, inout, number, numerator, denominator)	-- Return result of spelling (number, numerator, denominator), or	-- return nil if spelling is not available or not supported for given text.	-- Examples (each value must be a string or nil):	--   number  numerator  denominator  output	--   ------  ---------  -----------  -------------------	--   "1.23"    nil        nil        one point two three	--    "1"      "2"        "3"        one and two thirds	--    nil      "2"        "3"        two thirds	if not speller then		local function get_speller(module)			return require(module).spell_number		end		local success		success, speller = pcall(get_speller, spell_module)		if not success or type(speller) ~= 'function' then			add_warning(parms, 1, 'cvt_no_spell', 'spell')			return nil		end	end	local case	if parms.spell_upper == inout then		case = true		parms.spell_upper = nil  -- only uppercase first word in a multiple unit	end	local sp = not parms.opt_sp_us	local adj = parms.opt_adjectival	return speller(number, numerator, denominator, case, sp, adj)end-------------------------------------------------------------------------- BEGIN: Code required only for built-in units.-- LATER: If need much more code, move to another module to simplify this module.local function speed_of_sound(altitude)	-- This is for the Mach built-in unit of speed.	-- Return speed of sound in metres per second at given altitude in feet.	-- If no altitude given, use default (zero altitude = sea level).	-- Table gives speed of sound in miles per hour at various altitudes:	--   altitude = -17,499 to 302,499 feet	-- mach_table[a + 4] = s where	--   a = (altitude / 5000) rounded to nearest integer (-3 to 60)	--   s = speed of sound (mph) at that altitude	-- LATER: Should calculate result from an interpolation between the next	-- lower and higher altitudes in table, rather than rounding to nearest.	-- From: http://www.aerospaceweb.org/question/atmosphere/q0112.shtml	local mach_table = {                                                       -- a =		799.5, 787.0, 774.2, 761.207051,                                       -- -3 to  0		748.0, 734.6, 721.0, 707.0, 692.8, 678.3, 663.5, 660.1, 660.1, 660.1,  --  1 to 10		660.1, 660.1, 660.1, 662.0, 664.3, 666.5, 668.9, 671.1, 673.4, 675.6,  -- 11 to 20		677.9, 683.7, 689.9, 696.0, 702.1, 708.1, 714.0, 719.9, 725.8, 731.6,  -- 21 to 30		737.3, 737.7, 737.7, 736.2, 730.5, 724.6, 718.8, 712.9, 707.0, 701.1,  -- 31 to 40		695.0, 688.9, 682.8, 676.6, 670.4, 664.1, 657.8, 652.9, 648.3, 643.7,  -- 41 to 50		639.1, 634.4, 629.6, 624.8, 620.0, 615.2, 613.2, 613.2, 613.2, 613.5,  -- 51 to 60	}	altitude = altitude or 0	local a = (altitude < 0) and -altitude or altitude	a = floor(a / 5000 + 0.5)	if altitude < 0 then		a = -a	end	if a < -3 then		a = -3	elseif a > 60 then		a = 60	end	return mach_table[a + 4] * 0.44704  -- mph converted to m/send-- END: Code required only for built-in units.------------------------------------------------------------------------local function add_style(parms, class)	-- Add selected template style to parms if not already present.	parms.templatestyles = parms.templatestyles or {}	if not parms.templatestyles[class] then		parms.templatestyles[class] = parms.frame:extensionTag({			name = 'templatestyles', args = { src = text_code.titles[class] }		})	endendlocal function get_styles(parms)	-- Return string of required template styles, empty if none.	if parms.templatestyles then		local t = {}		for _, v in pairs(parms.templatestyles) do			table.insert(t, v)		end		return table.concat(t)	end	return ''endlocal function get_range(word)	-- Return a range (string or table) corresponding to word (like "to"),	-- or return nil if not a range word.	local ranges = text_code.ranges	return ranges.types[word] or ranges.types[ranges.aliases[word]]endlocal function check_mismatch(unit1, unit2)	-- If unit1 cannot be converted to unit2, return an error message table.	-- This allows conversion between units of the same type, and between	-- Nm (normally torque) and ftlb (energy), as in gun-related articles.	-- This works because Nm is the base unit (scale = 1) for both the	-- primary type (torque), and the alternate type (energy, where Nm = J).	-- A match occurs if the primary types are the same, or if unit1 matches	-- the alternate type of unit2, and vice versa. That provides a whitelist	-- of which conversions are permitted between normally incompatible types.	if unit1.utype == unit2.utype or		(unit1.utype == unit2.alttype and unit1.alttype == unit2.utype) then		return nil	end	return { 'cvt_mismatch', unit1.utype, unit2.utype }endlocal function override_from(out_table, in_table, fields)	-- Copy the specified fields from in_table to out_table, but do not	-- copy nil fields (keep any corresponding field in out_table).	for _, field in ipairs(fields) do		if in_table[field] then			out_table[field] = in_table[field]		end	endendlocal function shallow_copy(t)	-- Return a shallow copy of table t.	-- Do not need the features and overhead of the Scribunto mw.clone().	local result = {}	for k, v in pairs(t) do		result[k] = v	end	return resultendlocal unit_mt = {	-- Metatable to get missing values for a unit that does not accept SI prefixes.	-- Warning: The boolean value 'false' is returned for any missing field	-- so __index is not called twice for the same field in a given unit.	__index = function (self, key)		local value		if key == 'name1' or key == 'sym_us' then			value = self.symbol		elseif key == 'name2' then			value = self.name1 .. plural_suffix		elseif key == 'name1_us' then			value = self.name1			if not rawget(self, 'name2_us') then				-- If name1_us is 'foot', do not make name2_us by appending plural_suffix.				self.name2_us = self.name2			end		elseif key == 'name2_us' then			local raw1_us = rawget(self, 'name1_us')			if raw1_us then				value = raw1_us .. plural_suffix			else				value = self.name2			end		elseif key == 'link' then			value = self.name1		else			value = false		end		rawset(self, key, value)		return value	end}local function prefixed_name(unit, name, index)	-- Return unit name with SI prefix inserted at correct position.	-- index = 1 (name1), 2 (name2), 3 (name1_us), 4 (name2_us).	-- The position is a byte (not character) index, so use Lua's sub().	local pos = rawget(unit, 'prefix_position')	if type(pos) == 'string' then		pos = tonumber(split(pos, ',')[index])	end	if pos then		return name:sub(1, pos - 1) .. unit.si_name .. name:sub(pos)	end	return unit.si_name .. nameendlocal unit_prefixed_mt = {	-- Metatable to get missing values for a unit that accepts SI prefixes.	-- Before use, fields si_name, si_prefix must be defined.	-- The unit must define _symbol, _name1 and	-- may define _sym_us, _name1_us, _name2_us	-- (_sym_us, _name2_us may be defined for a language using sp=us	-- to refer to a variant unrelated to U.S. units).	__index = function (self, key)		local value		if key == 'symbol' then			value = self.si_prefix .. self._symbol		elseif key == 'sym_us' then			value = rawget(self, '_sym_us')			if value then				value = self.si_prefix .. value			else				value = self.symbol			end		elseif key == 'name1' then			value = prefixed_name(self, self._name1, 1)		elseif key == 'name2' then			value = rawget(self, '_name2')			if value then				value = prefixed_name(self, value, 2)			else				value = self.name1 .. plural_suffix			end		elseif key == 'name1_us' then			value = rawget(self, '_name1_us')			if value then				value = prefixed_name(self, value, 3)			else				value = self.name1			end		elseif key == 'name2_us' then			value = rawget(self, '_name2_us')			if value then				value = prefixed_name(self, value, 4)			elseif rawget(self, '_name1_us') then				value = self.name1_us .. plural_suffix			else				value = self.name2			end		elseif key == 'link' then			value = self.name1		else			value = false		end		rawset(self, key, value)		return value	end}local unit_per_mt = {	-- Metatable to get values for a per unit of form "x/y".	-- This is never called to determine a unit name or link because per units	-- are handled as a special case.	-- Similarly, the default output is handled elsewhere, and for a symbol	-- this is only called from get_default() for default_exceptions.	__index = function (self, key)		local value		if key == 'symbol' then			local per = self.per			local unit1, unit2 = per[1], per[2]			if unit1 then				value = unit1[key] .. '/' .. unit2[key]			else				value = '/' .. unit2[key]			end		elseif key == 'sym_us' then			value = self.symbol		elseif key == 'scale' then			local per = self.per			local unit1, unit2 = per[1], per[2]			value = (unit1 and unit1.scale or 1) * self.scalemultiplier / unit2.scale		else			value = false		end		rawset(self, key, value)		return value	end}local function make_per(unitcode, unit_table, ulookup)	-- Return true, t where t is a per unit with unit codes expanded to unit tables,	-- or return false, t where t is an error message table.	local result = {		unitcode = unitcode,		utype = unit_table.utype,		per = {}	}	override_from(result, unit_table, { 'invert', 'iscomplex', 'default', 'link', 'symbol', 'symlink' })	result.symbol_raw = (result.symbol or false)  -- to distinguish between a defined exception and a metatable calculation	local prefix	for i, v in ipairs(unit_table.per) do		if i == 1 and v == '' then			-- First unit symbol can be empty; that gives a nil first unit table.		elseif i == 1 and text_code.currency[v] then			prefix = currency_text or v		else			local success, t = ulookup(v)			if not success then return false, t end			result.per[i] = t		end	end	local multiplier = unit_table.multiplier	if not result.utype then		-- Creating an automatic per unit.		local unit1 = result.per[1]		local utype = (unit1 and unit1.utype or prefix or '') .. '/' .. result.per[2].utype		local t = data_code.per_unit_fixups[utype]		if t then			if type(t) == 'table' then				utype = t.utype or utype				result.link = result.link or t.link				multiplier = multiplier or t.multiplier			else				utype = t			end		end		result.utype = utype	end	result.scalemultiplier = multiplier or 1	result.vprefix = prefix or false  -- set to non-nil to avoid calling __index	return true, setmetatable(result, unit_per_mt)endlocal function lookup(parms, unitcode, what, utable, fails, depth)	-- Return true, t where t is a copy of the unit's converter table,	-- or return false, t where t is an error message table.	-- Parameter 'what' determines whether combination units are accepted:	--   'no_combination'  : single unit only	--   'any_combination' : single unit or combination or output multiple	--   'only_multiple'   : single unit or output multiple only	-- Parameter unitcode is a symbol (like 'g'), with an optional SI prefix (like 'kg').	-- If, for example, 'kg' is in this table, that entry is used;	-- otherwise the prefix ('k') is applied to the base unit ('g').	-- If unitcode is a known combination code (and if allowed by what),	-- a table of output multiple unit tables is included in the result.	-- For compatibility with the old template, an underscore in a unitcode is	-- replaced with a space so usage like {{convert|350|board_feet}} works.	-- Wikignomes may also put two spaces or "&nbsp;" in combinations, so	-- replace underscore, "&nbsp;", and multiple spaces with a single space.	utable = utable or parms.unittable or all_units	fails = fails or {}	depth = depth and depth + 1 or 1	if depth > 9 then		-- There are ways to mistakenly define units which result in infinite		-- recursion when lookup() is called. That gives a long delay and very		-- confusing error messages, so the depth parameter is used as a guard.		return false, { 'cvt_lookup', unitcode }	end	if unitcode == nil or unitcode == '' then		return false, { 'cvt_no_unit' }	end	unitcode = unitcode:gsub('_', ' '):gsub('&nbsp;', ' '):gsub('  +', ' ')	local function call_make_per(t)		return make_per(unitcode, t,			function (ucode) return lookup(parms, ucode, 'no_combination', utable, fails, depth) end		)	end	local t = utable[unitcode]	if t then		if t.shouldbe then			return false, { 'cvt_should_be', t.shouldbe }		end		if t.sp_us then			parms.opt_sp_us = true		end		local target = t.target  -- nil, or unitcode is an alias for this target		if target then			local success, result = lookup(parms, target, what, utable, fails, depth)			if not success then return false, result end			override_from(result, t, { 'customary', 'default', 'link', 'symbol', 'symlink' })			local multiplier = t.multiplier			if multiplier then				result.multiplier = tostring(multiplier)				result.scale = result.scale * multiplier			end			return true, result		end		if t.per then			return call_make_per(t)		end		local combo = t.combination  -- nil or a table of unitcodes		if combo then			local multiple = t.multiple			if what == 'no_combination' or (what == 'only_multiple' and not multiple) then				return false, { 'cvt_bad_unit', unitcode }			end			-- Recursively create a combination table containing the			-- converter table of each unitcode.			local result = { utype = t.utype, multiple = multiple, combination = {} }			local cvt = result.combination			for i, v in ipairs(combo) do				local success, t = lookup(parms, v, multiple and 'no_combination' or 'only_multiple', utable, fails, depth)				if not success then return false, t end				cvt[i] = t			end			return true, result		end		local result = shallow_copy(t)		result.unitcode = unitcode		if result.prefixes then			result.si_name = ''			result.si_prefix = ''			return true, setmetatable(result, unit_prefixed_mt)		end		return true, setmetatable(result, unit_mt)	end	local SIprefixes = text_code.SIprefixes	for plen = SIprefixes[1] or 2, 1, -1 do		-- Look for an SI prefix; should never occur with an alias.		-- Check for longer prefix first ('dam' is decametre).		-- SIprefixes[1] = prefix maximum #characters (as seen by mw.ustring.sub).		local prefix = usub(unitcode, 1, plen)		local si = SIprefixes[prefix]		if si then			local t = utable[usub(unitcode, plen+1)]			if t and t.prefixes then				local result = shallow_copy(t)				result.unitcode = unitcode				result.si_name = parms.opt_sp_us and si.name_us or si.name				result.si_prefix = si.prefix or prefix				result.scale = t.scale * 10 ^ (si.exponent * t.prefixes)				return true, setmetatable(result, unit_prefixed_mt)			end		end	end	-- Accept user-defined combinations like "acre+m2+ha" or "acre m2 ha" for output.	-- If '+' is used, each unit code can include a space, and any error is fatal.	-- If ' ' is used and if each space-separated word is a unit code, it is a combo,	-- but errors are not fatal so the unit code can be looked up as an extra unit.	local err_is_fatal	local combo = collection()	if unitcode:find('+', 1, true) then		err_is_fatal = true		for item in (unitcode .. '+'):gmatch('%s*(.-)%s*%+') do			if item ~= '' then				combo:add(item)			end		end	elseif unitcode:find('%s') then		for item in unitcode:gmatch('%S+') do			combo:add(item)		end	end	if combo.n > 1 then		local function lookup_combo()			if what == 'no_combination' or what == 'only_multiple' then				return false, { 'cvt_bad_unit', unitcode }			end			local result = { combination = {} }			local cvt = result.combination			for i, v in ipairs(combo) do				local success, t = lookup(parms, v, 'only_multiple', utable, fails, depth)				if not success then return false, t end				if i == 1 then					result.utype = t.utype				else					local mismatch = check_mismatch(result, t)					if mismatch then						return false, mismatch					end				end				cvt[i] = t			end			return true, result		end		local success, result = lookup_combo()		if success or err_is_fatal then			return success, result		end	end	-- Accept any unit with an engineering notation prefix like "e6cuft"	-- (million cubic feet), but not chained prefixes like "e3e6cuft",	-- and not if the unit is a combination or multiple,	-- and not if the unit has an offset or is a built-in.	-- Only en digits are accepted.	local exponent, baseunit = unitcode:match('^e(%d+)(.*)')	if exponent then		local engscale = text_code.eng_scales[exponent]		if engscale then			local success, result = lookup(parms, baseunit, 'no_combination', utable, fails, depth)			if success and not (result.offset or result.builtin or result.engscale) then				result.unitcode = unitcode  -- 'e6cuft' not 'cuft'				result.defkey = unitcode  -- key to lookup default exception				result.engscale = engscale				result.scale = result.scale * 10 ^ tonumber(exponent)				return true, result			end		end	end	-- Look for x/y; split on right-most slash to get scale correct (x/y/z is x/y per z).	local top, bottom = unitcode:match('^(.-)/([^/]+)$')	if top and not unitcode:find('e%d') then		-- If valid, create an automatic per unit for an "x/y" unit code.		-- The unitcode must not include extraneous spaces.		-- Engineering notation (apart from at start and which has been stripped before here),		-- is not supported so do not make a per unit if find text like 'e3' in unitcode.		local success, result = call_make_per({ per = {top, bottom} })		if success then			return true, result		end	end	if not parms.opt_ignore_error and not get_range(unitcode) then		-- Want the "what links here" list for the extra_module to show only cases		-- where an extra unit is used, so do not require it if invoked from {{val}}		-- or if looking up a range word which cannot be a unit.		if not extra_units then			local success, extra = pcall(function () return require(extra_module).extra_units end)			if success and type(extra) == 'table' then				extra_units = extra			end		end		if extra_units then			-- A unit in one data table might refer to a unit in the other table, so			-- switch between them, relying on fails or depth to terminate loops.			if not fails[unitcode] then				fails[unitcode] = true				local other = (utable == all_units) and extra_units or all_units				local success, result = lookup(parms, unitcode, what, other, fails, depth)				if success then					return true, result				end			end		end	end	if to_en_table then		-- At fawiki it is common to translate all digits so a unit like "km2" becomes "km۲".		local en_code = ustring.gsub(unitcode, '%d', to_en_table)		if en_code ~= unitcode then			return lookup(parms, en_code, what, utable, fails, depth)		end	end	return false, { 'cvt_unknown', unitcode }endlocal function valid_number(num)	-- Return true if num is a valid number.	-- In Scribunto (different from some standard Lua), when expressed as a string,	-- overflow or other problems are indicated with text like "inf" or "nan"	-- which are regarded as invalid here (each contains "n").	if type(num) == 'number' and tostring(num):find('n', 1, true) == nil then		return true	endendlocal function hyphenated(name, parts)	-- Return a hyphenated form of given name (for adjectival usage).	-- The name may be linked and the target of the link must not be changed.	-- Hypothetical examples:	--   [[long ton|ton]]         →  [[long ton|ton]]          (no change)	--   [[tonne|long ton]]       →  [[tonne|long-ton]]	--   [[metric ton|long ton]]  →  [[metric ton|long-ton]]	--   [[long ton]]             →  [[long ton|long-ton]]	-- Input can also have multiple links in a single name like:	--   [[United States customary units|U.S.]] [[US gallon|gallon]]	--   [[mile]]s per [[United States customary units|U.S.]] [[quart]]	--   [[long ton]]s per [[short ton]]	-- Assume that links cannot be nested (never like "[[abc[[def]]ghi]]").	-- This uses a simple and efficient procedure that works for most cases.	-- Some units (if used) would require more, and can later think about	-- adding a method to handle exceptions.	-- The procedure is to replace each space with a hyphen, but	-- not a space after ')' [for "(pre-1954&nbsp;US) nautical mile"], and	-- not spaces immediately before '(' or in '(...)' [for cases like	-- "British thermal unit (ISO)" and "Calorie (International Steam Table)"].	if name:find(' ', 1, true) then		if parts then			local pos			if name:sub(1, 1) == '(' then				pos = name:find(')', 1, true)				if pos then					return name:sub(1, pos+1) .. name:sub(pos+2):gsub(' ', '-')				end			elseif name:sub(-1) == ')' then				pos = name:find('(', 1, true)				if pos then					return name:sub(1, pos-2):gsub(' ', '-') .. name:sub(pos-1)				end			end			return name:gsub(' ', '-')		end		parts = collection()		for before, item, after in name:gmatch('([^[]*)(%[%[[^[]*%]%])([^[]*)') do			if item:find(' ', 1, true) then				local prefix				local plen = item:find('|', 1, true)				if plen then					prefix = item:sub(1, plen)					item = item:sub(plen + 1, -3)				else					prefix = item:sub(1, -3) .. '|'					item = item:sub(3, -3)				end				item = prefix .. hyphenated(item, parts) .. ']]'			end			parts:add(before:gsub(' ', '-') .. item .. after:gsub(' ', '-'))		end		if parts.n == 0 then			-- No link like "[[...]]" was found in the original name.			parts:add(hyphenated(name, parts))		end		return table.concat(parts)	end	return nameendlocal function hyphenated_maybe(parms, want_name, sep, id, inout)	-- Return s, f where	--   s = id, possibly modified	--   f = true if hyphenated	-- Possible modifications: hyphenate; prepend '-'; append mid text.	if id == nil or id == '' then		return ''	end	local mid = (inout == (parms.opt_flip and 'out' or 'in')) and parms.mid or ''	if want_name then		if parms.opt_adjectival then			return '-' .. hyphenated(id) .. mid, true		end		if parms.opt_add_s and id:sub(-1) ~= 's' then			id = id .. 's'  -- for nowiki		end	end	return sep .. id .. midendlocal function use_minus(text)	-- Return text with Unicode minus instead of '-', if present.	if text:sub(1, 1) == '-' then		return MINUS .. text:sub(2)	end	return textendlocal function digit_groups(parms, text, method)	-- Return a numbered table of groups of digits (left-to-right, in local language).	-- Parameter method is a number or nil:	--   3 for 3-digit grouping (default), or	--   2 for 3-then-2 grouping (only for digits before decimal mark).	local len_right	local len_left = text:find('.', 1, true)	if len_left then		len_right = #text - len_left		len_left = len_left - 1	else		len_left = #text	end	local twos = method == 2 and len_left > 5	local groups = collection()	local run = len_left	local n	if run < 4 or (run == 4 and parms.opt_comma5) then		if parms.opt_gaps then			n = run		else			n = #text		end	elseif twos then		n = run % 2 == 0 and 1 or 2	else		n = run % 3 == 0 and 3 or run % 3	end	while run > 0 do		groups:add(n)		run = run - n		n = (twos and run > 3) and 2 or 3	end	if len_right then		if groups.n == 0 then			groups:add(0)		end		if parms.opt_gaps and len_right > 3 then			local want4 = not parms.opt_gaps3  -- true gives no gap before trailing single digit			local isfirst = true			run = len_right			while run > 0 do				n = (want4 and run == 4) and 4 or (run > 3 and 3 or run)				if isfirst then					isfirst = false					groups[groups.n] = groups[groups.n] + 1 + n				else					groups:add(n)				end				run = run - n			end		else			groups[groups.n] = groups[groups.n] + 1 + len_right		end	end	local pos = 1	for i, length in ipairs(groups) do		groups[i] = from_en(text:sub(pos, pos + length - 1))		pos = pos + length	end	return groupsendfunction with_separator(parms, text)  -- for forward declaration above	-- Input text is a number in en digits with optional '.' decimal mark.	-- Return an equivalent, formatted for display:	--   with a custom decimal mark instead of '.', if wanted	--   with thousand separators inserted, if wanted	--   digits in local language	-- The given text is like '123' or '123.' or '12345.6789'.	-- The text has no sign (caller inserts that later, if necessary).	-- When using gaps, they are inserted before and after the decimal mark.	-- Separators are inserted only before the decimal mark.	-- A trailing dot (as in '123.') is removed because their use appears to	-- be accidental, and such a number should be shown as '123' or '123.0'.	-- It is useful for convert to suppress the dot so, for example, '4000.'	-- is a simple way of indicating that all the digits are significant.	if text:sub(-1) == '.' then		text = text:sub(1, -2)	end	if #text < 4 or parms.opt_nocomma or numsep == '' then		return from_en(text)	end	local groups = digit_groups(parms, text, group_method)	if parms.opt_gaps then		if groups.n <= 1 then			return groups[1] or ''		end		local nowrap = '<span style="white-space: nowrap">'		local gap = '<span style="margin-left: 0.25em">'		local close = '</span>'		return nowrap .. groups[1] .. gap .. table.concat(groups, close .. gap, 2, groups.n) .. close .. close	end	return table.concat(groups, numsep)end-- An input value like 1.23e12 is displayed using scientific notation (1.23×10¹²).-- That also makes the output use scientific notation, except for small values.-- In addition, very small or very large output values use scientific notation.-- Use format(fmtpower, significand, '10', exponent) where each argument is a string.local fmtpower = '%s<span style="margin:0 .15em 0 .25em">×</span>%s<sup>%s</sup>'local function with_exponent(parms, show, exponent)	-- Return wikitext to display the implied value in scientific notation.	-- Input uses en digits; output uses digits in local language.	return format(fmtpower, with_separator(parms, show), from_en('10'), use_minus(from_en(tostring(exponent))))endlocal function make_sigfig(value, sigfig)	-- Return show, exponent that are equivalent to the result of	-- converting the number 'value' (where value >= 0) to a string,	-- rounded to 'sigfig' significant figures.	-- The returned items are:	--   show: a string of digits; no sign and no dot;	--         there is an implied dot before show.	--   exponent: a number (an integer) to shift the implied dot.	-- Resulting value = tonumber('.' .. show) * 10^exponent.	-- Examples:	--   make_sigfig(23.456, 3) returns '235', 2 (.235 * 10^2).	--   make_sigfig(0.0023456, 3) returns '235', -2 (.235 * 10^-2).	--   make_sigfig(0, 3) returns '000', 1 (.000 * 10^1).	if sigfig <= 0 then		sigfig = 1	elseif sigfig > maxsigfig then		sigfig = maxsigfig	end	if value == 0 then		return string.rep('0', sigfig), 1	end	local exp, fracpart = math.modf(log10(value))	if fracpart >= 0 then		fracpart = fracpart - 1		exp = exp + 1	end	local digits = format('%.0f', 10^(fracpart + sigfig))	if #digits > sigfig then		-- Overflow (for sigfig=3: like 0.9999 rounding to "1000"; need "100").		digits = digits:sub(1, sigfig)		exp = exp + 1	end	assert(#digits == sigfig, 'Bug: rounded number has wrong length')	return digits, expend-- Fraction output format.local fracfmt = {	{ -- Like {{frac}} (fraction slash).		'<span class="frac" role="math">{SIGN}<span class="num">{NUM}</span>&frasl;<span class="den">{DEN}</span></span>',  -- 1/2		'<span class="frac" role="math">{SIGN}{WHOLE}<span class="sr-only">+</span><span class="num">{NUM}</span>&frasl;<span class="den">{DEN}</span></span>',  -- 1+2/3		style = 'frac',	},	{ -- Like {{sfrac}} (stacked fraction, that is, horizontal bar).		'<span class="sfrac tion" role="math">{SIGN}<span class="num">{NUM}</span><span class="sr-only">/</span><span class="den">{DEN}</span></span>',  -- 1//2		'<span class="sfrac" role="math">{SIGN}{WHOLE}<span class="sr-only">+</span><span class="tion"><span class="num">{NUM}</span><span class="sr-only">/</span><span class="den">{DEN}</span></span></span>',  -- 1+2//3		style = 'sfrac',	},}local function format_fraction(parms, inout, negative, wholestr, numstr, denstr, do_spell, style)	-- Return wikitext for a fraction, possibly spelled.	-- Inputs use en digits and have no sign; output uses digits in local language.	local wikitext	if not style then		style = parms.opt_fraction_horizontal and 2 or 1	end	if wholestr == '' then		wholestr = nil	end	local substitute = {		SIGN = negative and MINUS or '',		WHOLE = wholestr and with_separator(parms, wholestr),		NUM = from_en(numstr),		DEN = from_en(denstr),	}	wikitext = fracfmt[style][wholestr and 2 or 1]:gsub('{(%u+)}', substitute)	if do_spell then		if negative then			if wholestr then				wholestr = '-' .. wholestr			else				numstr = '-' .. numstr			end		end		local s = spell_number(parms, inout, wholestr, numstr, denstr)		if s then			return s		end	end	add_style(parms, fracfmt[style].style)	return wikitextendlocal function format_number(parms, show, exponent, isnegative)	-- Parameter show is a string or a table containing strings.	-- Each string is a formatted number in en digits and optional '.' decimal mark.	-- A table represents a fraction: integer, numerator, denominator;	-- if a table is given, exponent must be nil.	-- Return t where t is a table with fields:	--   show = wikitext formatted to display implied value	--          (digits in local language)	--   is_scientific = true if show uses scientific notation	--   clean = unformatted show (possibly adjusted and with inserted '.')	--          (en digits)	--   sign = '' or MINUS	--   exponent = exponent (possibly adjusted)	-- The clean and exponent fields can be used to calculate the	-- rounded absolute value, if needed.	--	-- The value implied by the arguments is found from:	--   exponent is nil; and	--   show is a string of digits (no sign), with an optional dot;	--   show = '123.4' is value 123.4, '1234' is value 1234.0;	-- or:	--   exponent is an integer indicating where dot should be;	--   show is a string of digits (no sign and no dot);	--   there is an implied dot before show;	--   show does not start with '0';	--   show = '1234', exponent = 3 is value 0.1234*10^3 = 123.4.	--	-- The formatted result:	-- * Is for an output value and is spelled if wanted and possible.	-- * Includes a Unicode minus if isnegative and not spelled.	-- * Uses a custom decimal mark, if wanted.	-- * Has digits grouped where necessary, if wanted.	-- * Uses scientific notation if requested, or for very small or large values	--   (which forces result to not be spelled).	-- * Has no more than maxsigfig significant digits	--   (same as old template and {{#expr}}).	local xhi, xlo  -- these control when scientific notation (exponent) is used	if parms.opt_scientific then		xhi, xlo = 4, 2  -- default for output if input uses e-notation	elseif parms.opt_scientific_always then		xhi, xlo = 0, 0  -- always use scientific notation (experimental)	else		xhi, xlo = 10, 4  -- default	end	local sign = isnegative and MINUS or ''	local maxlen = maxsigfig	local tfrac	if type(show) == 'table' then		tfrac = show		show = tfrac.wholestr		assert(exponent == nil, 'Bug: exponent given with fraction')	end	if not tfrac and not exponent then		local integer, dot, decimals = show:match('^(%d*)(%.?)(.*)')		if integer == '0' or integer == '' then			local zeros, figs = decimals:match('^(0*)([^0]?.*)')			if #figs == 0 then				if #zeros > maxlen then					show = '0.' .. zeros:sub(1, maxlen)				end			elseif #zeros >= xlo then				show = figs				exponent = -#zeros			elseif #figs > maxlen then				show = '0.' .. zeros .. figs:sub(1, maxlen)			end		elseif #integer >= xhi then			show = integer .. decimals			exponent = #integer		else			maxlen = maxlen + #dot			if #show > maxlen then				show = show:sub(1, maxlen)			end		end	end	if exponent then		local function zeros(n)			return string.rep('0', n)		end		if #show > maxlen then			show = show:sub(1, maxlen)		end		if exponent > xhi or exponent <= -xlo or (exponent == xhi and show ~= '1' .. zeros(xhi - 1)) then			-- When xhi, xlo = 10, 4 (the default), scientific notation is used if the			-- rounded value satisfies: value >= 1e9 or value < 1e-4 (1e9 = 0.1e10),			-- except if show is '1000000000' (1e9), for example:			-- {{convert|1000000000|m|m|sigfig=10}} → 1,000,000,000 metres (1,000,000,000 m)			local significand			if #show > 1 then				significand = show:sub(1, 1) .. '.' .. show:sub(2)			else				significand = show			end			return {				clean = '.' .. show,				exponent = exponent,				sign = sign,				show = sign .. with_exponent(parms, significand, exponent-1),				is_scientific = true,			}		end		if exponent >= #show then			show = show .. zeros(exponent - #show)  -- result has no dot		elseif exponent <= 0 then			show = '0.' .. zeros(-exponent) .. show		else			show = show:sub(1, exponent) .. '.' .. show:sub(exponent+1)		end	end	local formatted_show	if tfrac then		show = tostring(tfrac.value)  -- to set clean in returned table		formatted_show = format_fraction(parms, 'out', isnegative, tfrac.wholestr, tfrac.numstr, tfrac.denstr, parms.opt_spell_out)	else		if isnegative and show:match('^0.?0*$') then			sign = ''  -- don't show minus if result is negative but rounds to zero		end		formatted_show = sign .. with_separator(parms, show)		if parms.opt_spell_out then			formatted_show = spell_number(parms, 'out', sign .. show) or formatted_show		end	end	return {		clean = show,		sign = sign,		show = formatted_show,		is_scientific = false,  -- to avoid calling __index	}endlocal function extract_fraction(parms, text, negative)	-- If text represents a fraction, return	--   value, altvalue, show, denominator	-- where	--   value is a number (value of the fraction in argument text)	--   altvalue is an alternate interpretation of any fraction for the hands	--        unit where "12.1+3/4" means 12 hands 1.75 inches	--   show is a string (formatted text for display of an input value,	--        and is spelled if wanted and possible)	--   denominator is value of the denominator in the fraction	-- Otherwise, return nil.	-- Input uses en digits and '.' decimal mark (input has been translated).	-- Output uses digits in local language and local decimal mark, if any.	------------------------------------------------------------------------	-- Originally this function accepted x+y/z where x, y, z were any valid	-- numbers, possibly with a sign. For example '1.23e+2+1.2/2.4' = 123.5,	-- and '2-3/8' = 1.625. However, such usages were found to be errors or	-- misunderstandings, so since August 2014 the following restrictions apply:	--   x (if present) is an integer or has a single digit after decimal mark	--   y and z are unsigned integers	--   e-notation is not accepted	-- The overall number can start with '+' or '-' (so '12+3/4' and '+12+3/4'	-- and '-12-3/4' are valid).	-- Any leading negative sign is removed by the caller, so only inputs	-- like the following are accepted here (may have whitespace):	--   negative = false       false        true (there was a leading '-')	--   text     = '2/3'       '+2/3'       '2/3'	--   text     = '1+2/3'     '+1+2/3'     '1-2/3'	--   text     = '12.3+1/2'  '+12.3+1/2'  '12.3-1/2'	-- Values like '12.3+1/2' are accepted, but are intended only for use	-- with the hands unit (not worth adding code to enforce that).	------------------------------------------------------------------------	local leading_plus, prefix, numstr, slashes, denstr =		text:match('^%s*(%+?)%s*(.-)%s*(%d+)%s*(/+)%s*(%d+)%s*$')	if not leading_plus then		-- Accept a single U+2044 fraction slash because that may be pasted.		leading_plus, prefix, numstr, denstr =			text:match('^%s*(%+?)%s*(.-)%s*(%d+)%s*⁄%s*(%d+)%s*$')		slashes = '/'	end	local numerator = tonumber(numstr)	local denominator = tonumber(denstr)	if numerator == nil or denominator == nil or (negative and leading_plus ~= '') then		return nil	end	local whole, wholestr	if prefix == '' then		wholestr = ''		whole = 0	else		-- Any prefix must be like '12+' or '12-' (whole number and fraction sign);		-- '12.3+' and '12.3-' are also accepted (single digit after decimal point)		-- because '12.3+1/2 hands' is valid (12 hands 3½ inches).		local num1, num2, frac_sign = prefix:match('^(%d+)(%.?%d?)%s*([+%-])$')		if num1 == nil then return nil end		if num2 == '' then  -- num2 must be '' or like '.1' but not '.' or '.12'			wholestr = num1		else			if #num2 ~= 2 then return nil end			wholestr = num1 .. num2		end		if frac_sign ~= (negative and '-' or '+') then return nil end		whole = tonumber(wholestr)		if whole == nil then return nil end	end	local value = whole + numerator / denominator	if not valid_number(value) then return nil end	local altvalue = whole + numerator / (denominator * 10)	local style = #slashes  -- kludge: 1 or 2 slashes can be used to select style	if style > 2 then style = 2 end	local wikitext = format_fraction(parms, 'in', negative, leading_plus .. wholestr, numstr, denstr, parms.opt_spell_in, style)	return value, altvalue, wikitext, denominatorendlocal function extract_number(parms, text, another, no_fraction)	-- Return true, info if can extract a number from text,	-- where info is a table with the result,	-- or return false, t where t is an error message table.	-- Input can use en digits or digits in local language and can	-- have references at the end. Accepting references is intended	-- for use in infoboxes with a field for a value passed to convert.	-- Parameter another = true if the expected value is not the first.	-- Before processing, the input text is cleaned:	-- * Any thousand separators (valid or not) are removed.	-- * Any sign is replaced with '-' (if negative) or '' (otherwise).	--   That replaces Unicode minus with '-'.	-- If successful, the returned info table contains named fields:	--   value    = a valid number	--   altvalue = a valid number, usually same as value but different	--              if fraction used (for hands unit)	--   singular = true if value is 1 or -1 (to use singular form of units)	--   clean    = cleaned text with any separators and sign removed	--              (en digits and '.' decimal mark)	--   show     = text formatted for output, possibly with ref strip markers	--              (digits in local language and custom decimal mark)	-- The resulting show:	-- * Is for an input value and is spelled if wanted and possible.	-- * Has a rounded value, if wanted.	-- * Has digits grouped where necessary, if wanted.	-- * If negative, a Unicode minus is used; otherwise the sign is	--   '+' (if the input text used '+'), or is '' (if no sign in input).	text = strip(text or '')	local reference	local pos = text:find('\127', 1, true)	if pos then		local before = text:sub(1, pos - 1)		local remainder = text:sub(pos)		local refs = {}		while #remainder > 0 do			local ref, spaces			ref, spaces, remainder = remainder:match('^(\127[^\127]*UNIQ[^\127]*%-ref[^\127]*\127)(%s*)(.*)')			if ref then				table.insert(refs, ref)			else				refs = {}				break			end		end		if #refs > 0 then			text = strip(before)			reference = table.concat(refs)		end	end	local clean = to_en(text, parms)	if clean == '' then		return false, { another and 'cvt_no_num2' or 'cvt_no_num' }	end	local isnegative, propersign = false, ''  -- most common case	local singular, show, denominator	local value = tonumber(clean)	local altvalue	if value then		local sign = clean:sub(1, 1)		if sign == '+' or sign == '-' then			propersign = (sign == '+') and '+' or MINUS			clean = clean:sub(2)		end		if value < 0 then			isnegative = true			value = -value		end	else		local valstr		for _, prefix in ipairs({ '-', MINUS, '&minus;' }) do			-- Including '-' sets isnegative in case input is a fraction like '-2-3/4'.			local plen = #prefix			if clean:sub(1, plen) == prefix then				valstr = clean:sub(plen + 1)				if valstr:match('^%s') then  -- "- 1" is invalid but "-1 - 1/2" is ok					return false, { 'cvt_bad_num', text }				end				break			end		end		if valstr then			isnegative = true			propersign = MINUS			clean = valstr			value = tonumber(clean)		end		if value == nil then			if not no_fraction then				value, altvalue, show, denominator = extract_fraction(parms, clean, isnegative)			end			if value == nil then				return false, { 'cvt_bad_num', text }			end			if value <= 1 then				singular = true  -- for example, "½ mile" or "one half mile" (singular unit)			end		end	end	if not valid_number(value) then  -- for example, "1e310" may overflow		return false, { 'cvt_invalid_num' }	end	if show == nil then		-- clean is a non-empty string with no spaces, and does not represent a fraction,		-- and value = tonumber(clean) is a number >= 0.		-- If the input uses e-notation, show will be displayed using a power of ten, but		-- we use the number as given so it might not be normalized scientific notation.		-- The input value is spelled if specified so any e-notation is ignored;		-- that allows input like 2e6 to be spelled as "two million" which works		-- because the spell module converts '2e6' to '2000000' before spelling.		local function rounded(value, default, exponent)			local precision = parms.opt_ri			if precision then				local fmt = '%.' .. format('%d', precision) .. 'f'				local result = fmt:format(tonumber(value) + 2e-14)  -- fudge for some common cases of bad rounding				if not exponent then					singular = (tonumber(result) == 1)				end				return result			end			return default		end		singular = (value == 1)		local scientific		local significand, exponent = clean:match('^([%d.]+)[Ee]([+%-]?%d+)')		if significand then			show = with_exponent(parms, rounded(significand, significand, exponent), exponent)			scientific = true		else			show = with_separator(parms, rounded(value, clean))		end		show = propersign .. show		if parms.opt_spell_in then			show = spell_number(parms, 'in', propersign .. rounded(value, clean)) or show			scientific = false		end		if scientific then			parms.opt_scientific = true		end	end	if isnegative and (value ~= 0) then		value = -value		altvalue = -(altvalue or value)	end	return true, {		value = value,		altvalue = altvalue or value,		singular = singular,		clean = clean,		show = show .. (reference or ''),		denominator = denominator,	}endlocal function get_number(text)	-- Return v, f where:	--   v = nil (text is not a number)	-- or	--   v = value of text (text is a number)	--   f = true if value is an integer	-- Input can use en digits or digits in local language,	-- but no separators, no Unicode minus, and no fraction.	if text then		local number = tonumber(to_en(text))		if number then			local _, fracpart = math.modf(number)			return number, (fracpart == 0)		end	endendlocal function gcd(a, b)	-- Return the greatest common denominator for the given values,	-- which are known to be positive integers.	if a > b then		a, b = b, a	end	if a <= 0 then		return b	end	local r = b % a	if r <= 0 then		return a	end	if r == 1 then		return 1	end	return gcd(r, a)endlocal function fraction_table(value, denominator)	-- Return value as a string or a table:	-- * If result is a string, there is no fraction, and the result	--   is value formatted as a string of en digits.	-- * If result is a table, it represents a fraction with named fields:	--   wholestr, numstr, denstr (strings of en digits for integer, numerator, denominator).	-- The result is rounded to the nearest multiple of (1/denominator).	-- If the multiple is zero, no fraction is included.	-- No fraction is included if value is very large as the fraction would	-- be unhelpful, particularly if scientific notation is required.	-- Input value is a non-negative number.	-- Input denominator is a positive integer for the desired fraction.	if value <= 0 then		return '0'	end	if denominator <= 0 or value > 1e8 then		return format('%.2f', value)	end	local integer, decimals = math.modf(value)	local numerator = floor((decimals * denominator) +		0.5 + 2e-14)  -- add fudge for some common cases of bad rounding	if numerator >= denominator then		integer = integer + 1		numerator = 0	end	local wholestr = tostring(integer)	if numerator > 0 then		local div = gcd(numerator, denominator)		if div > 1 then			numerator = numerator / div			denominator = denominator / div		end		return {			wholestr = (integer > 0) and wholestr or '',			numstr = tostring(numerator),			denstr = tostring(denominator),			value = value,		}	end	return wholestrendlocal function preunits(count, preunit1, preunit2)	-- If count is 1:	--     ignore preunit2	--     return p1	-- else:	--     preunit1 is used for preunit2 if the latter is empty	--     return p1, p2	-- where:	--     p1 is text to insert before the input unit	--     p2 is text to insert before the output unit	--     p1 or p2 may be nil to mean "no preunit"	-- Using '+' gives output like "5+ feet" (no space before, but space after).	local function withspace(text, wantboth)		-- Return text with space before and, if wantboth, after.		-- However, no space is added if there is a space or '&nbsp;' or '-'		-- at that position ('-' is for adjectival text).		-- There is also no space if text starts with '&'		-- (e.g. '&deg;' would display a degree symbol with no preceding space).		local char = text:sub(1, 1)		if char == '&' then			return text  -- an html entity can be used to specify the exact display		end		if not (char == ' ' or char == '-' or char == '+') then			text = ' ' .. text		end		if wantboth then			char = text:sub(-1, -1)			if not (char == ' ' or char == '-' or text:sub(-6, -1) == '&nbsp;') then				text = text .. ' '			end		end		return text	end	local PLUS = '+ '	preunit1 = preunit1 or ''	local trim1 = strip(preunit1)	if count == 1 then		if trim1 == '' then			return nil		end		if trim1 == '+' then			return PLUS		end		return withspace(preunit1, true)	end	preunit1 = withspace(preunit1)	preunit2 = preunit2 or ''	local trim2 = strip(preunit2)	if trim1 == '+' then		if trim2 == '' or trim2 == '+' then			return PLUS, PLUS		end		preunit1 = PLUS	end	if trim2 == '' then		if trim1 == '' then			return nil, nil		end		preunit2 = preunit1	elseif trim2 == '+' then		preunit2 = PLUS	elseif trim2 == '&#32;' then  -- trick to make preunit2 empty		preunit2 = nil	else		preunit2 = withspace(preunit2)	end	return preunit1, preunit2endlocal function range_text(range, want_name, parms, before, after, inout)	-- Return before .. rtext .. after	-- where rtext is the text that separates two values in a range.	local rtext, adj_text, exception	if type(range) == 'table' then		-- Table must specify range text for ('off' and 'on') or ('input' and 'output'),		-- and may specify range text for 'adj=on',		-- and may specify exception = true.		rtext = range[want_name and 'off' or 'on'] or				range[((inout == 'in') == (parms.opt_flip == true)) and 'output' or 'input']		adj_text = range['adj']		exception = range['exception']	else		rtext = range	end	if parms.opt_adjectival then		if want_name or (exception and parms.abbr_org == 'on') then			rtext = adj_text or rtext:gsub(' ', '-'):gsub('&nbsp;', '-')		end	end	if rtext == '–' and after:sub(1, #MINUS) == MINUS then		rtext = '&nbsp;– '	end	return before .. rtext .. afterendlocal function get_composite(parms, iparm, in_unit_table)	-- Look for a composite input unit. For example, {{convert|1|yd|2|ft|3|in}}	-- would result in a call to this function with	--   iparm = 3 (parms[iparm] = "2", just after the first unit)	--   in_unit_table = (unit table for "yd"; contains value 1 for number of yards)	-- Return true, iparm, unit where	--   iparm = index just after the composite units (7 in above example)	--   unit = composite unit table holding all input units,	-- or return true if no composite unit is present in parms,	-- or return false, t where t is an error message table.	local default, subinfo	local composite_units, count = { in_unit_table }, 1	local fixups = {}	local total = in_unit_table.valinfo[1].value	local subunit = in_unit_table	while subunit.subdivs do  -- subdivs is nil or a table of allowed subdivisions		local subcode = strip(parms[iparm+1])		local subdiv = subunit.subdivs[subcode] or subunit.subdivs[(all_units[subcode] or {}).target]		if not subdiv then			break		end		local success		success, subunit = lookup(parms, subcode, 'no_combination')		if not success then return false, subunit end  -- should never occur		success, subinfo = extract_number(parms, parms[iparm])		if not success then return false, subinfo end		iparm = iparm + 2		subunit.inout = 'in'		subunit.valinfo = { subinfo }		-- Recalculate total as a number of subdivisions.		-- subdiv[1] = number of subdivisions per previous unit (integer > 1).		total = total * subdiv[1] + subinfo.value		if not default then  -- set by the first subdiv with a default defined			default = subdiv.default		end		count = count + 1		composite_units[count] = subunit		if subdiv.unit or subdiv.name then			fixups[count] = { unit = subdiv.unit, name = subdiv.name, valinfo = subunit.valinfo }		end	end	if count == 1 then		return true  -- no error and no composite unit	end	for i, fixup in pairs(fixups) do		local unit = fixup.unit		local name = fixup.name		if not unit or (count > 2 and name) then			composite_units[i].fixed_name = name		else			local success, alternate = lookup(parms, unit, 'no_combination')			if not success then return false, alternate end  -- should never occur			alternate.inout = 'in'			alternate.valinfo = fixup.valinfo			composite_units[i] = alternate		end	end	return true, iparm, {		utype = in_unit_table.utype,		scale = subunit.scale,  -- scale of last (least significant) unit		valinfo = { { value = total, clean = subinfo.clean, denominator = subinfo.denominator } },		composite = composite_units,		default = default or in_unit_table.default	}endlocal function translate_parms(parms, kv_pairs)	-- Update fields in parms by translating each key:value in kv_pairs to terms	-- used by this module (may involve translating from local language to English).	-- Also, checks are performed which may display warnings, if enabled.	-- Return true if successful or return false, t where t is an error message table.	currency_text = nil  -- local testing can hold module in memory; must clear globals	local accept_any_text = {		input = true,		qid = true,		qual = true,		stylein = true,		styleout = true,		tracking = true,	}	if kv_pairs.adj and kv_pairs.sing then		-- For enwiki (before translation), warn if attempt to use adj and sing		-- as the latter is a deprecated alias for the former.		if kv_pairs.adj ~= kv_pairs.sing and kv_pairs.sing ~= '' then			add_warning(parms, 1, 'cvt_unknown_option', 'sing=' .. kv_pairs.sing)		end		kv_pairs.sing = nil	end	kv_pairs.comma = kv_pairs.comma or config.comma  -- for plwiki who want default comma=5	for loc_name, loc_value in pairs(kv_pairs) do		local en_name = text_code.en_option_name[loc_name]		if en_name then			local en_value			if en_name == '$' or en_name == 'frac' or en_name == 'sigfig' then				if loc_value == '' then					add_warning(parms, 2, 'cvt_empty_option', loc_name)				elseif en_name == '$' then					-- Value should be a single character like "€" for the euro currency symbol, but anything is accepted.					currency_text = (loc_value == 'euro') and '€' or loc_value				else					local minimum					local number, is_integer = get_number(loc_value)					if en_name == 'frac' then						minimum = 2						if number and number < 0 then							parms.opt_fraction_horizontal = true							number = -number						end					else						minimum = 1					end					if number and is_integer and number >= minimum then						en_value = number					else						add_warning(parms, 1, (en_name == 'frac' and 'cvt_bad_frac' or 'cvt_bad_sigfig'), loc_name .. '=' .. loc_value)					end				end			elseif accept_any_text[en_name] then				en_value = loc_value ~= '' and loc_value or nil  -- accept non-empty user text with no validation				if en_name == 'input' then					-- May have something like {{convert|input=}} (empty input) if source is an infobox					-- with optional fields. In that case, want to output nothing rather than an error.					parms.input_text = loc_value  -- keep input because parms.input is nil if loc_value == ''				end			else				en_value = text_code.en_option_value[en_name][loc_value]				if en_value and en_value:sub(-1) == '?' then					en_value = en_value:sub(1, -2)					add_warning(parms, -1, 'cvt_deprecated', loc_name .. '=' .. loc_value)				end				if en_value == nil then					if loc_value == '' then						add_warning(parms, 2, 'cvt_empty_option', loc_name)					else						add_warning(parms, 1, 'cvt_unknown_option', loc_name .. '=' .. loc_value)					end				elseif en_value == '' then					en_value = nil  -- an ignored option like adj=off				elseif type(en_value) == 'string' and en_value:sub(1, 4) == 'opt_' then					for _, v in ipairs(split(en_value, ',')) do						local lhs, rhs = v:match('^(.-)=(.+)$')						if rhs then							parms[lhs] = tonumber(rhs) or rhs						else							parms[v] = true						end					end					en_value = nil				end			end			parms[en_name] = en_value		else			add_warning(parms, 1, 'cvt_unknown_option', loc_name .. '=' .. loc_value)		end	end	local abbr_entered = parms.abbr	local cfg_abbr = config.abbr	if cfg_abbr then		-- Don't warn if invalid because every convert would show that warning.		if cfg_abbr == 'on always' then			parms.abbr = 'on'		elseif cfg_abbr == 'off always' then			parms.abbr = 'off'		elseif parms.abbr == nil then			if cfg_abbr == 'on default' then				parms.abbr = 'on'			elseif cfg_abbr == 'off default' then				parms.abbr = 'off'			end		end	end	if parms.abbr then		if parms.abbr == 'unit' then			parms.abbr = 'on'			parms.number_word = true		end		parms.abbr_org = parms.abbr  -- original abbr, before any flip	elseif parms.opt_hand_hh then		parms.abbr_org = 'on'		parms.abbr = 'on'	else		parms.abbr = 'out'  -- default is to abbreviate output only (use symbol, not name)	end	if parms.opt_order_out then		-- Disable options that do not work in a useful way with order=out.		parms.opt_flip = nil  -- override adj=flip		parms.opt_spell_in = nil		parms.opt_spell_out = nil		parms.opt_spell_upper = nil	end	if parms.opt_spell_out and not abbr_entered then		parms.abbr = 'off'  -- should show unit name when spelling the output value	end	if parms.opt_flip then		local function swap_in_out(option)			local value = parms[option]			if value == 'in' then				parms[option] = 'out'			elseif value == 'out' then				parms[option] = 'in'			end		end		swap_in_out('abbr')		swap_in_out('lk')		if parms.opt_spell_in and not parms.opt_spell_out then			-- For simplicity, and because it does not appear to be needed,			-- user cannot set an option to spell the output only.			parms.opt_spell_in = nil			parms.opt_spell_out = true		end	end	if parms.opt_spell_upper then		parms.spell_upper = parms.opt_flip and 'out' or 'in'	end	if parms.opt_table or parms.opt_tablecen then		if abbr_entered == nil and parms.lk == nil then			parms.opt_values = true		end		parms.table_align = parms.opt_table and 'right' or 'center'	end	if parms.table_align or parms.opt_sortable_on then		parms.need_table_or_sort = true	end	local disp_joins = text_code.disp_joins	local default_joins = disp_joins['b']	parms.join_between = default_joins[3] or '; '	local disp = parms.disp	if disp == nil then  -- special case for the most common setting		parms.joins = default_joins	elseif disp == 'x' then		-- Later, parms.joins is set from the input parameters.	else		-- Old template does this.		local abbr = parms.abbr		if disp == 'slash' then			if abbr_entered == nil then				disp = 'slash-nbsp'			elseif abbr == 'in' or abbr == 'out' then				disp = 'slash-sp'			else				disp = 'slash-nosp'			end		elseif disp == 'sqbr' then			if abbr == 'on' then				disp = 'sqbr-nbsp'			else				disp = 'sqbr-sp'			end		end		parms.joins = disp_joins[disp] or default_joins		parms.join_between = parms.joins[3] or parms.join_between		parms.wantname = parms.joins.wantname	end	if (en_default and not parms.opt_lang_local and (parms[1] or ''):find('%d')) or parms.opt_lang_en then		from_en_table = nil	end	if en_default and from_en_table then		-- For hiwiki: localized symbol/name is defined with the US symbol/name field,		-- and is used if output uses localized numbers.		parms.opt_sp_us = true	end	return trueendlocal function get_values(parms)	-- If successful, update parms and return true, v, i where	--   v = table of input values	--   i = index to next entry in parms after those processed here	-- or return false, t where t is an error message table.	local valinfo = collection()  -- numbered table of input values	local range = collection()  -- numbered table of range items (having, for example, 2 range items requires 3 input values)	local had_nocomma  -- true if removed "nocomma" kludge from second parameter (like "tonocomma")	local parm2 = strip(parms[2])	if parm2 and parm2:sub(-7, -1) == 'nocomma' then		parms[2] = strip(parm2:sub(1, -8))		parms.opt_nocomma = true		had_nocomma = true	end	local function extractor(i)		-- If the parameter is not a value, try unpacking it as a range ("1-23" for "1 to 23").		-- However, "-1-2/3" is a negative fraction (-1⅔), so it must be extracted first.		-- Do not unpack a parameter if it is like "3-1/2" which is sometimes incorrectly		-- used instead of "3+1/2" (and which should not be interpreted as "3 to ½").		-- Unpacked items are inserted into the parms table.		-- The tail recursion allows combinations like "1x2 to 3x4".		local valstr = strip(parms[i])  -- trim so any '-' as a negative sign will be at start		local success, result = extract_number(parms, valstr, i > 1)		if not success and valstr and i < 20 then  -- check i to limit abuse			local lhs, sep, rhs = valstr:match('^(%S+)%s+(%S+)%s+(%S.*)')			if lhs and not (sep == '-' and rhs:match('/')) then				if sep:find('%d') then					return success, result  -- to reject {{convert|1 234 567|m}} with a decent message (en only)				end				parms[i] = rhs				table.insert(parms, i, sep)				table.insert(parms, i, lhs)				return extractor(i)			end			if not valstr:match('%-.*/') then				for _, sep in ipairs(text_code.ranges.words) do					local start, stop = valstr:find(sep, 2, true)  -- start at 2 to skip any negative sign for range '-'					if start then						parms[i] = valstr:sub(stop + 1)						table.insert(parms, i, sep)						table.insert(parms, i, valstr:sub(1, start - 1))						return extractor(i)					end				end			end		end		return success, result	end	local i = 1	local is_change	while true do		local success, info = extractor(i)  -- need to set parms.opt_nocomma before calling this		if not success then return false, info end		i = i + 1		if is_change then			info.is_change = true  -- value is after "±" and so is a change (significant for range like {{convert|5|±|5|°C}})			is_change = nil		end		valinfo:add(info)		local range_item = get_range(strip(parms[i]))		if not range_item then			break		end		i = i + 1		range:add(range_item)		if type(range_item) == 'table' then			-- For range "x", if append unit to some values, append it to all.			parms.in_range_x = parms.in_range_x or range_item.in_range_x			parms.out_range_x = parms.out_range_x or range_item.out_range_x			parms.abbr_range_x = parms.abbr_range_x or range_item.abbr_range_x			is_change = range_item.is_range_change		end	end	if range.n > 0 then		if range.n > 30 then  -- limit abuse, although 4 is a more likely upper limit			return false, { 'cvt_invalid_num' }  -- misleading message but it will do		end		parms.range = range	elseif had_nocomma then		return false, { 'cvt_unknown', parm2 }	end	return true, valinfo, iendlocal function simple_get_values(parms)	-- If input is like "{{convert|valid_value|valid_unit|...}}",	-- return true, i, in_unit, in_unit_table	-- i = index in parms of what follows valid_unit, if anything.	-- The valid_value is not negative and does not use a fraction, and	-- no options requiring further processing of the input are used.	-- Otherwise, return nothing or return false, parm1 for caller to interpret.	-- Testing shows this function is successful for 96% of converts in articles,	-- and that on average it speeds up converts by 8%.	local clean = to_en(strip(parms[1] or ''), parms)	if parms.opt_ri or parms.opt_spell_in or #clean > 10 or not clean:match('^[0-9.]+$') then		return false, clean	end	local value = tonumber(clean)	if not value then return end	local info = {		value = value,		altvalue = value,		singular = (value == 1),		clean = clean,		show = with_separator(parms, clean),	}	local in_unit = strip(parms[2])	local success, in_unit_table = lookup(parms, in_unit, 'no_combination')	if not success then return end	in_unit_table.valinfo = { info }	return true, 3, in_unit, in_unit_tableendlocal function wikidata_call(parms, operation, ...)	-- Return true, s where s is the result of a Wikidata operation,	-- or return false, t where t is an error message table.	local function worker(...)		wikidata_code = wikidata_code or require(wikidata_module)		wikidata_data = wikidata_data or mw.loadData(wikidata_data_module)		return wikidata_code[operation](wikidata_data, ...)	end	local success, status, result = pcall(worker, ...)	if success then		return status, result	end	if parms.opt_sortable_debug then		-- Use debug=yes to crash if an error while accessing Wikidata.		error('Error accessing Wikidata: ' .. status, 0)	end	return false, { 'cvt_wd_fail' }endlocal function get_parms(parms, args)	-- If successful, update parms and return true, unit where	--   parms is a table of all arguments passed to the template	--        converted to named arguments, and	--   unit is the input unit table;	-- or return false, t where t is an error message table.	-- For special processing (not a convert), can also return	-- true, wikitext where wikitext is the final result.	-- The returned input unit table may be for a fake unit using the specified	-- unit code as the symbol and name, and with bad_mcode = message code table.	-- MediaWiki removes leading and trailing whitespace from the values of	-- named arguments. However, the values of numbered arguments include any	-- whitespace entered in the template, and whitespace is used by some	-- parameters (example: the numbered parameters associated with "disp=x").	local kv_pairs = {}  -- table of input key:value pairs where key is a name; needed because cannot iterate parms and add new fields to it	for k, v in pairs(args) do		if type(k) == 'number' or k == 'test' then  -- parameter "test" is reserved for testing and is not translated			parms[k] = v		else			kv_pairs[k] = v		end	end	if parms.test == 'wikidata' then		local ulookup = function (ucode)			-- Use empty table for parms so it does not accumulate results when used repeatedly.			return lookup({}, ucode, 'no_combination')		end		return wikidata_call(parms, '_listunits', ulookup)	end	local success, msg = translate_parms(parms, kv_pairs)	if not success then return false, msg end	if parms.input then		success, msg = wikidata_call(parms, '_adjustparameters', parms, 1)		if not success then return false, msg end	end	local success, i, in_unit, in_unit_table = simple_get_values(parms)	if not success then		if type(i) == 'string' and i:match('^NNN+$') then			-- Some infoboxes have examples like {{convert|NNN|m}} (3 or more "N").			-- Output an empty string for these.			return false, { 'cvt_no_output' }		end		local valinfo		success, valinfo, i = get_values(parms)		if not success then return false, valinfo end		in_unit = strip(parms[i])		i = i + 1		success, in_unit_table = lookup(parms, in_unit, 'no_combination')		if not success then			in_unit = in_unit or ''			if parms.opt_ignore_error then  -- display given unit code with no error (for use with {{val}})				in_unit_table = ''  -- suppress error message and prevent processing of output unit			end			in_unit_table = setmetatable({				symbol = in_unit, name2 = in_unit, utype = in_unit,				scale = 1, default = '', defkey = '', linkey = '',				bad_mcode = in_unit_table }, unit_mt)		end		in_unit_table.valinfo = valinfo	end	if parms.test == 'msg' then		-- Am testing the messages produced when no output unit is specified, and		-- the input unit has a missing or invalid default.		-- Set two units for testing that.		-- LATER: Remove this code.		if in_unit == 'chain' then			in_unit_table.default = nil  -- no default		elseif in_unit == 'rd' then			in_unit_table.default  = "ft!X!m"  -- an invalid expression		end	end	in_unit_table.inout = 'in'  -- this is an input unit	if not parms.range then		local success, inext, composite_unit = get_composite(parms, i, in_unit_table)		if not success then return false, inext end		if composite_unit then			in_unit_table = composite_unit			i = inext		end	end	if in_unit_table.builtin == 'mach' then		-- As with old template, a number following Mach as the input unit is the altitude,		-- and there is no way to specify an altitude for the output unit.		-- Could put more code in this function to get any output unit and check for		-- an altitude following that unit.		local success, info = extract_number(parms, parms[i], false, true)		if success then			i = i + 1			in_unit_table.altitude = info.value		end	end	local word = strip(parms[i])	i = i + 1	local precision, is_bad_precision	local function set_precision(text)		local number, is_integer = get_number(text)		if number then			if is_integer then				precision = number			else				precision = text				is_bad_precision = true			end			return true  -- text was used for precision, good or bad		end	end	if word and not set_precision(word) then		parms.out_unit = parms.out_unit or word		if set_precision(strip(parms[i])) then			i = i + 1		end	end	if parms.opt_adj_mid then		word = parms[i]		i = i + 1		if word then  -- mid-text words			if word:sub(1, 1) == '-' then				parms.mid = word			else				parms.mid = ' ' .. word			end		end	end	if parms.opt_one_preunit then		parms[parms.opt_flip and 'preunit2' or 'preunit1'] = preunits(1, parms[i])		i = i + 1	end	if parms.disp == 'x' then		-- Following is reasonably compatible with the old template.		local first = parms[i] or ''		local second = parms[i+1] or ''		i = i + 2		if strip(first) == '' then  -- user can enter '&#32;' rather than ' ' to avoid the default			first = ' [&nbsp;' .. first			second = '&nbsp;]' .. second		end		parms.joins = { first, second }	elseif parms.opt_two_preunits then		local p1, p2 = preunits(2, parms[i], parms[i+1])		i = i + 2		if parms.preunit1 then			-- To simplify documentation, allow unlikely use of adj=pre with disp=preunit			-- (however, an output unit must be specified with adj=pre and with disp=preunit).			parms.preunit1 = parms.preunit1 .. p1			parms.preunit2 = p2		else			parms.preunit1, parms.preunit2 = p1, p2		end	end	if precision == nil then		if set_precision(strip(parms[i])) then			i = i + 1		end	end	if is_bad_precision then		add_warning(parms, 1, 'cvt_bad_prec', precision)	else		parms.precision = precision	end	for j = i, i + 3 do		local parm = parms[j]  -- warn if find a non-empty extraneous parameter		if parm and parm:match('%S') then			add_warning(parms, 1, 'cvt_unknown_option', parm)			break		end	end	return true, in_unit_tableendlocal function record_default_precision(parms, out_current, precision)	-- If necessary, adjust parameters and return a possibly adjusted precision.	-- When converting a range of values where a default precision is required,	-- that default is calculated for each value because the result sometimes	-- depends on the precise input and output values. This function may cause	-- the entire convert process to be repeated in order to ensure that the	-- same default precision is used for each individual convert.	-- If that were not done, a range like 1000 to 1000.4 may give poor results	-- because the first output could be heavily rounded, while the second is not.	-- For range 1000.4 to 1000, this function can give the second convert the	-- same default precision that was used for the first.	if not parms.opt_round_each then		local maxdef = out_current.max_default_precision		if maxdef then			if maxdef < precision then				parms.do_convert_again = true				out_current.max_default_precision = precision			else				precision = out_current.max_default_precision			end		else			out_current.max_default_precision = precision		end	end	return precisionendlocal function default_precision(parms, invalue, inclean, denominator, outvalue, in_current, out_current, extra)	-- Return a default value for precision (an integer like 2, 0, -2).	-- If denominator is not nil, it is the value of the denominator in inclean.	-- Code follows procedures used in old template.	local fudge = 1e-14  -- {{Order of magnitude}} adds this, so we do too	local prec, minprec, adjust	local subunit_ignore_trailing_zero	local subunit_more_precision  -- kludge for "in" used in input like "|2|ft|6|in"	local composite = in_current.composite	if composite then		subunit_ignore_trailing_zero = true  -- input "|2|st|10|lb" has precision 0, not -1		if composite[#composite].exception == 'subunit_more_precision' then			subunit_more_precision = true  -- do not use standard precision with input like "|2|ft|6|in"		end	end	if denominator and denominator > 0 then		prec = math.max(log10(denominator), 1)	else		-- Count digits after decimal mark, handling cases like '12.345e6'.		local exponent		local integer, dot, decimals, expstr = inclean:match('^(%d*)(%.?)(%d*)(.*)')		local e = expstr:sub(1, 1)		if e == 'e' or e == 'E' then			exponent = tonumber(expstr:sub(2))		end		if dot == '' then			prec = subunit_ignore_trailing_zero and 0 or -integer:match('0*$'):len()		else			prec = #decimals		end		if exponent then			-- So '1230' and '1.23e3' both give prec = -1, and '0.00123' and '1.23e-3' give 5.			prec = prec - exponent		end	end	if in_current.istemperature and out_current.istemperature then		-- Converting between common temperatures (°C, °F, °R, K); not keVT.		-- Kelvin value can be almost zero, or small but negative due to precision problems.		-- Also, an input value like -300 C (below absolute zero) gives negative kelvins.		-- Calculate minimum precision from absolute value.		adjust = 0		local kelvin = abs((invalue - in_current.offset) * in_current.scale)		if kelvin < 1e-8 then  -- assume nonzero due to input or calculation precision problem			minprec = 2		else			minprec = 2 - floor(log10(kelvin) + fudge)  -- 3 sigfigs in kelvin		end	else		if invalue == 0 or outvalue <= 0 then			-- We are never called with a negative outvalue, but it might be zero.			-- This is special-cased to avoid calculation exceptions.			return record_default_precision(parms, out_current, 0)		end		if out_current.exception == 'integer_more_precision' and floor(invalue) == invalue then			-- With certain output units that sometimes give poor results			-- with default rounding, use more precision when the input			-- value is equal to an integer. An example of a poor result			-- is when input 50 gives a smaller output than input 49.5.			-- Experiment shows this helps, but it does not eliminate all			-- surprises because it is not clear whether "50" should be			-- interpreted as "from 45 to 55" or "from 49.5 to 50.5".			adjust = -log10(in_current.scale)		elseif subunit_more_precision then			-- Conversion like "{{convert|6|ft|1|in|cm}}" (where subunit is "in")			-- has a non-standard adjust value, to give more output precision.			adjust = log10(out_current.scale) + 2		else			adjust = log10(abs(invalue / outvalue))		end		adjust = adjust + log10(2)		-- Ensure that the output has at least two significant figures.		minprec = 1 - floor(log10(outvalue) + fudge)	end	if extra then		adjust = extra.adjust or adjust		minprec = extra.minprec or minprec	end	return record_default_precision(parms, out_current, math.max(floor(prec + adjust), minprec))endlocal function convert(parms, invalue, info, in_current, out_current)	-- Convert given input value from one unit to another.	-- Return output_value (a number) if a simple convert, or	-- return f, t where	--   f = true, t = table of information with results, or	--   f = false, t = error message table.	local inscale = in_current.scale	local outscale = out_current.scale	if not in_current.iscomplex and not out_current.iscomplex then		return invalue * (inscale / outscale)  -- minimize overhead for most common case	end	if in_current.invert or out_current.invert then		-- Inverted units, such as inverse length, inverse time, or		-- fuel efficiency. Built-in units do not have invert set.		if (in_current.invert or 1) * (out_current.invert or 1) < 0 then			return 1 / (invalue * inscale * outscale)		end		return invalue * (inscale / outscale)	elseif in_current.offset then		-- Temperature (there are no built-ins for this type of unit).		if info.is_change then			return invalue * (inscale / outscale)		end		return (invalue - in_current.offset) * (inscale / outscale) + out_current.offset	else		-- Built-in unit.		local in_builtin = in_current.builtin		local out_builtin = out_current.builtin		if in_builtin and out_builtin then			if in_builtin == out_builtin then				return invalue			end			-- There are no cases (yet) where need to convert from one			-- built-in unit to another, so this should never occur.			return false, { 'cvt_bug_convert' }		end		if in_builtin == 'mach' or out_builtin == 'mach' then			local adjust			if in_builtin == 'mach' then				inscale = speed_of_sound(in_current.altitude)				adjust = outscale / 0.1			else				outscale = speed_of_sound(out_current.altitude)				adjust = 0.1 / inscale			end			return true, {				outvalue = invalue * (inscale / outscale),				adjust = log10(adjust) + log10(2),			}		elseif in_builtin == 'hand' then			-- 1 hand = 4 inches; 1.2 hands = 6 inches.			-- Decimals of a hand are only defined for the first digit, and			-- the first fractional digit should be a number of inches (1, 2 or 3).			-- However, this code interprets the entire fractional part as the number			-- of inches / 10 (so 1.75 inches would be 0.175 hands).			-- A value like 12.3 hands is exactly 12*4 + 3 inches; base default precision on that.			local integer, fracpart = math.modf(invalue)			local inch_value = 4 * integer + 10 * fracpart  -- equivalent number of inches			local factor = inscale / outscale			if factor == 4 then				-- Am converting to inches: show exact result, and use "inches" not "in" by default.				if parms.abbr_org == nil then					out_current.usename = true				end				local show = format('%g', abs(inch_value))  -- show and clean are unsigned				if not show:find('e', 1, true) then					return true, {						invalue = inch_value,						outvalue = inch_value,						clean = show,						show = show,					}				end			end			local outvalue = (integer + 2.5 * fracpart) * factor			local fracstr = info.clean:match('%.(.*)') or ''			local fmt			if fracstr == '' then				fmt = '%.0f'			else				fmt = '%.' .. format('%d', #fracstr - 1) .. 'f'			end			return true, {				invalue = inch_value,				clean = format(fmt, inch_value),				outvalue = outvalue,				minprec = 0,			}		end	end	return false, { 'cvt_bug_convert' }  -- should never occurendlocal function user_style(parms, i)	-- Return text for a user-specified style for a table cell, or '' if none,	-- given i = 1 (input style) or 2 (output style).	local style = parms[(i == 1) and 'stylein' or 'styleout']	if style then		style = style:gsub('"', '')		if style ~= '' then			if style:sub(-1) ~= ';' then				style = style .. ';'			end			return style		end	end	return ''endlocal function make_table_or_sort(parms, invalue, info, in_current, scaled_top)	-- Set options to handle output for a table or a sort key, or both.	-- The text sort key is based on the value resulting from converting	-- the input to a fake base unit with scale = 1, and other properties	-- required for a conversion derived from the input unit.	-- For other modules, return the sort key in a hidden span element, and	-- the scaled value used to generate the sort key.	-- If scaled_top is set, it is the scaled value of the numerator of a per unit	-- to be combined with this unit (the denominator) to make the sort key.	-- Scaling only works with units that convert with a factor (not temperature).	local sortkey, scaled_value	if parms.opt_sortable_on then		local base = {  -- a fake unit with enough fields for a valid convert			scale = 1,			invert = in_current.invert and 1,			iscomplex = in_current.iscomplex,			offset = in_current.offset and 0,		}		local outvalue, extra = convert(parms, invalue, info, in_current, base)		if extra then			outvalue = extra.outvalue		end		if in_current.istemperature then			-- Have converted to kelvin; assume numbers close to zero have a			-- rounding error and should be zero.			if abs(outvalue) < 1e-12 then				outvalue = 0			end		end		if scaled_top and outvalue ~= 0 then			outvalue = scaled_top / outvalue		end		scaled_value = outvalue		if not valid_number(outvalue) then			if outvalue < 0 then				sortkey = '1000000000000000000'			else				sortkey = '9000000000000000000'			end		elseif outvalue == 0 then			sortkey = '5000000000000000000'		else			local mag = floor(log10(abs(outvalue)) + 1e-14)			local prefix			if outvalue > 0 then				prefix = 7000 + mag			else				prefix = 2999 - mag				outvalue = outvalue + 10^(mag+1)			end			sortkey = format('%d', prefix) .. format('%015.0f', floor(outvalue * 10^(14-mag)))		end	end	local sortspan	if sortkey and not parms.table_align then		sortspan = parms.opt_sortable_debug and			'<span data-sort-value="' .. sortkey .. '♠"><span style="border:1px solid">' .. sortkey .. '♠</span></span>' or			'<span data-sort-value="' .. sortkey .. '♠"></span>'		parms.join_before = sortspan	end	if parms.table_align then		local sort		if sortkey then			sort = ' data-sort-value="' .. sortkey .. '"'			if parms.opt_sortable_debug then				parms.join_before = '<span style="border:1px solid">' .. sortkey .. '</span>'			end		else			sort = ''		end		local style = 'style="text-align:' .. parms.table_align .. ';'		local joins = {}		for i = 1, 2 do			joins[i] = (i == 1 and '' or '\n|') .. style .. user_style(parms, i) .. '"' .. sort .. '|'		end		parms.table_joins = joins	end	return sortspan, scaled_valueendlocal cvt_to_handlocal function cvtround(parms, info, in_current, out_current)	-- Return true, t where t is a table with the conversion results; fields:	--   show = rounded, formatted string with the result of converting value in info,	--      using the rounding specified in parms.	--   singular = true if result (after rounding and ignoring any negative sign)	--      is "1", or like "1.00", or is a fraction with value < 1;	--   (and more fields shown below, and a calculated 'absvalue' field).	-- or return false, t where t is an error message table.	-- Input info.clean uses en digits (it has been translated, if necessary).	-- Output show uses en or non-en digits as appropriate, or can be spelled.	if out_current.builtin == 'hand' then		return cvt_to_hand(parms, info, in_current, out_current)	end	local invalue = in_current.builtin == 'hand' and info.altvalue or info.value	local outvalue, extra = convert(parms, invalue, info, in_current, out_current)	if parms.need_table_or_sort then		parms.need_table_or_sort = nil  -- process using first input value only		make_table_or_sort(parms, invalue, info, in_current)	end	if extra then		if not outvalue then return false, extra end		invalue = extra.invalue or invalue		outvalue = extra.outvalue	end	if not valid_number(outvalue) then		return false, { 'cvt_invalid_num' }	end	local isnegative	if outvalue < 0 then		isnegative = true		outvalue = -outvalue	end	local precision, show, exponent	local denominator = out_current.frac	if denominator then		show = fraction_table(outvalue, denominator)	else		precision = parms.precision		if not precision then			if parms.sigfig then				show, exponent = make_sigfig(outvalue, parms.sigfig)			elseif parms.opt_round then				local n = parms.opt_round				if n == 0.5 then					local integer, fracpart = math.modf(floor(2 * outvalue + 0.5) / 2)					if fracpart == 0 then						show = format('%.0f', integer)					else						show = format('%.1f', integer + fracpart)					end				else					show = format('%.0f', floor((outvalue / n) + 0.5) * n)				end			else				local inclean = info.clean				if extra then					inclean = extra.clean or inclean					show = extra.show				end				if not show then					precision = default_precision(parms, invalue, inclean, info.denominator, outvalue, in_current, out_current, extra)				end			end		end	end	if precision then		if precision >= 0 then			local fudge			if precision <= 8 then				-- Add a fudge to handle common cases of bad rounding due to inability				-- to precisely represent some values. This makes the following work:				-- {{convert|-100.1|C|K}} and {{convert|5555000|um|m|2}}.				-- Old template uses #expr round, which invokes PHP round().				-- LATER: Investigate how PHP round() works.				fudge = 2e-14			else				fudge = 0			end			local fmt = '%.' .. format('%d', precision) .. 'f'			local success			success, show = pcall(format, fmt, outvalue + fudge)			if not success then				return false, { 'cvt_big_prec', tostring(precision) }			end		else			precision = -precision  -- #digits to zero (in addition to any digits after dot)			local shift = 10 ^ precision			show = format('%.0f', outvalue/shift)			if show ~= '0' then				exponent = #show + precision			end		end	end	local t = format_number(parms, show, exponent, isnegative)	if type(show) == 'string' then		-- Set singular using match because on some systems 0.99999999999999999 is 1.0.		if exponent then			t.singular = (exponent == 1 and show:match('^10*$'))		else			t.singular = (show == '1' or show:match('^1%.0*$'))		end	else		t.fraction_table = show		t.singular = (outvalue <= 1)  -- cannot have 'fraction == 1', but if it were possible it would be singular	end	t.raw_absvalue = outvalue  -- absolute value before rounding	return true, setmetatable(t, {		__index = function (self, key)			if key == 'absvalue' then				-- Calculate absolute value after rounding, if needed.				local clean, exponent = rawget(self, 'clean'), rawget(self, 'exponent')				local value = tonumber(clean)  -- absolute value (any negative sign has been ignored)				if exponent then					value = value * 10^exponent				end				rawset(self, key, value)				return value			end		end })endfunction cvt_to_hand(parms, info, in_current, out_current)	-- Convert input to hands, inches.	-- Return true, t where t is a table with the conversion results;	-- or return false, t where t is an error message table.	if parms.abbr_org == nil then		out_current.usename = true  -- default is to show name not symbol	end	local precision = parms.precision	local frac = out_current.frac	if not frac and precision and precision > 1 then		frac = (precision == 2) and 2 or 4	end	local out_next = out_current.out_next	if out_next then		-- Use magic knowledge to determine whether the next unit is inches without requiring i18n.		-- The following ensures that when the output combination "hand in" is used, the inches		-- value is rounded to match the hands value. Also, displaying say "61½" instead of 61.5		-- is better as 61.5 implies the value is not 61.4.		if out_next.exception == 'subunit_more_precision' then			out_next.frac = frac		end	end	-- Convert to inches; calculate hands from that.	local dummy_unit_table = { scale = out_current.scale / 4, frac = frac }	local success, outinfo = cvtround(parms, info, in_current, dummy_unit_table)	if not success then return false, outinfo end	local tfrac = outinfo.fraction_table	local inches = outinfo.raw_absvalue	if tfrac then		inches = floor(inches)  -- integer part only; fraction added later	else		inches = floor(inches + 0.5)  -- a hands measurement never shows decimals of an inch	end	local hands, inches = divide(inches, 4)	outinfo.absvalue = hands + inches/4  -- supposed to be the absolute rounded value, but this is close enough	local inchstr = tostring(inches)  -- '0', '1', '2' or '3'	if precision and precision <= 0 then  -- using negative or 0 for precision rounds to nearest hand		hands = floor(outinfo.raw_absvalue/4 + 0.5)		inchstr = ''	elseif tfrac then		-- Always show an integer before fraction (like "15.0½") because "15½" means 15-and-a-half hands.		inchstr = numdot .. format_fraction(parms, 'out', false, inchstr, tfrac.numstr, tfrac.denstr)	else		inchstr = numdot .. from_en(inchstr)	end	outinfo.show = outinfo.sign .. with_separator(parms, format('%.0f', hands)) .. inchstr	return true, outinfoendlocal function evaluate_condition(value, condition)	-- Return true or false from applying a conditional expression to value,	-- or throw an error if invalid.	-- A very limited set of expressions is supported:	--    v < 9	--    v * 9 < 9	-- where	--    'v' is replaced with value	--    9 is any number (as defined by Lua tonumber)	--      only en digits are accepted	--    '<' can also be '<=' or '>' or '>='	-- In addition, the following form is supported:	--    LHS and RHS	-- where	--    LHS, RHS = any of above expressions.	local function compare(value, text)		local arithop, factor, compop, limit = text:match('^%s*v%s*([*]?)(.-)([<>]=?)(.*)$')		if arithop == nil then			error('Invalid default expression', 0)		elseif arithop == '*' then			factor = tonumber(factor)			if factor == nil then				error('Invalid default expression', 0)			end			value = value * factor		end		limit = tonumber(limit)		if limit == nil then			error('Invalid default expression', 0)		end		if compop == '<' then			return value < limit		elseif compop == '<=' then			return value <= limit		elseif compop == '>' then			return value > limit		elseif compop == '>=' then			return value >= limit		end		error('Invalid default expression', 0)  -- should not occur	end	local lhs, rhs = condition:match('^(.-%W)and(%W.*)')	if lhs == nil then		return compare(value, condition)	end	return compare(value, lhs) and compare(value, rhs)endlocal function get_default(value, unit_table)	-- Return true, s where s = name of unit's default output unit,	-- or return false, t where t is an error message table.	-- Some units have a default that depends on the input value	-- (the first value if a range of values is used).	-- If '!' is in the default, the first bang-delimited field is an	-- expression that uses 'v' to represent the input value.	-- Example: 'v < 120 ! small ! big ! suffix' (suffix is optional)	-- evaluates 'v < 120' as a boolean with result	-- 'smallsuffix' if (value < 120), or 'bigsuffix' otherwise.	-- Input must use en digits and '.' decimal mark.	local default = data_code.default_exceptions[unit_table.defkey or unit_table.symbol] or unit_table.default	if not default then		local per = unit_table.per		if per then			local function a_default(v, u)				local success, ucode = get_default(v, u)				if not success then					return '?'  -- an unlikely error has occurred; will cause lookup of default to fail				end				-- Attempt to use only the first unit if a combination or output multiple.				-- This is not bulletproof but should work for most cases.				-- Where it does not work, the convert will need to specify the wanted output unit.				local t = all_units[ucode]				if t then					local combo = t.combination					if combo then						-- For a multiple like ftin, the "first" unit (ft) is last in the combination.						local i = t.multiple and table_len(combo) or 1						ucode = combo[i]					end				else					-- Try for an automatically generated combination.					local item = ucode:match('^(.-)%+') or ucode:match('^(%S+)%s')					if all_units[item] then						return item					end				end				return ucode			end			local unit1, unit2 = per[1], per[2]			local def1 = (unit1 and a_default(value, unit1) or unit_table.vprefix or '')			local def2 = a_default(1, unit2)  -- 1 because per unit of denominator			return true, def1 .. '/' .. def2		end		return false, { 'cvt_no_default', unit_table.symbol }	end	if default:find('!', 1, true) == nil then		return true, default	end	local t = split(default, '!')	if #t == 3 or #t == 4 then		local success, result = pcall(evaluate_condition, value, t[1])		if success then			default = result and t[2] or t[3]			if #t == 4 then				default = default .. t[4]			end			return true, default		end	end	return false, { 'cvt_bad_default', unit_table.symbol }endlocal linked_pages  -- to record linked pages so will not link to the same page more than oncelocal function unlink(unit_table)	-- Forget that the given unit has previously been linked (if it has).	-- That is needed when processing a range of inputs or outputs when an id	-- for the first range value may have been evaluated, but only an id for	-- the last value is displayed, and that id may need to be linked.	linked_pages[unit_table.unitcode or unit_table] = nilendlocal function make_link(link, id, unit_table)	-- Return wikilink "[[link|id]]", possibly abbreviated as in examples:	--   [[Mile|mile]]  --> [[mile]]	--   [[Mile|miles]] --> [[mile]]s	-- However, just id is returned if:	-- * no link given (so caller does not need to check if a link was defined); or	-- * link has previously been used during the current convert (to avoid overlinking).	local link_key	if unit_table then		link_key = unit_table.unitcode or unit_table	else		link_key = link	end	if not link or link == '' or linked_pages[link_key] then		return id	end	linked_pages[link_key] = true	-- Following only works for language en, but it should be safe on other wikis,	-- and overhead of doing it generally does not seem worthwhile.	local l = link:sub(1, 1):lower() .. link:sub(2)	if link == id or l == id then		return '[[' .. id .. ']]'	elseif link .. 's' == id or l .. 's' == id then		return '[[' .. id:sub(1, -2) .. ']]s'	else		return '[[' .. link .. '|' .. id .. ']]'	endendlocal function variable_name(clean, unit_table)	-- For slwiki, a unit name depends on the value.	-- Parameter clean is the unsigned rounded value in en digits, as a string.	-- Value             Source    Example for "m"	-- integer 1:        name1     meter  (also is the name of the unit)	-- integer 2:        var{1}    metra	-- integer 3 and 4:  var{2}    metri	-- integer else:     var{3}    metrov (0 and 5 or more)	-- real/fraction:    var{4}    metra	-- var{i} means the i'th field in unit_table.varname if it exists and has	-- an i'th field, otherwise name2.	-- Fields are separated with "!" and are not empty.	-- A field for a unit using an SI prefix has the prefix name inserted,	-- replacing '#' if found, or before the field otherwise.	local vname	if clean == '1' then		vname = unit_table.name1	elseif unit_table.varname then		local i		if clean == '2' then			i = 1		elseif clean == '3' or clean == '4' then			i = 2		elseif clean:find('.', 1, true) then			i = 4		else			i = 3		end		if i > 1 and varname == 'pl' then			i = i - 1		end		vname = split(unit_table.varname, '!')[i]	end	if vname then		local si_name = rawget(unit_table, 'si_name') or ''		local pos = vname:find('#', 1, true)		if pos then			vname = vname:sub(1, pos - 1) .. si_name .. vname:sub(pos + 1)		else			vname = si_name .. vname		end		return vname	end	return unit_table.name2endlocal function linked_id(parms, unit_table, key_id, want_link, clean)	-- Return final unit id (symbol or name), optionally with a wikilink,	-- and update unit_table.sep if required.	-- key_id is one of: 'symbol', 'sym_us', 'name1', 'name1_us', 'name2', 'name2_us'.	local abbr_on = (key_id == 'symbol' or key_id == 'sym_us')	if abbr_on and want_link then		local symlink = rawget(unit_table, 'symlink')		if symlink then			return symlink  -- for exceptions that have the linked symbol built-in		end	end	local multiplier = rawget(unit_table, 'multiplier')	local per = unit_table.per	if per then		local paren1, paren2 = '', ''  -- possible parentheses around bottom unit		local unit1 = per[1]  -- top unit_table, or nil		local unit2 = per[2]  -- bottom unit_table		if abbr_on then			if not unit1 then				unit_table.sep = ''  -- no separator in "$2/acre"			end			if not want_link then				local symbol = unit_table.symbol_raw				if symbol then					return symbol  -- for exceptions that have the symbol built-in				end			end			if (unit2.symbol):find('⋅', 1, true) then				paren1, paren2 = '(', ')'			end		end		local key_id2  -- unit2 is always singular		if key_id == 'name2' then			key_id2 = 'name1'		elseif key_id == 'name2_us' then			key_id2 = 'name1_us'		else			key_id2 = key_id		end		local result		if abbr_on then			result = '/'		elseif omitsep then			result = per_word		elseif unit1 then			result = ' ' .. per_word .. ' '		else			result = per_word .. ' '		end		if want_link and unit_table.link then			if abbr_on or not varname then				result = (unit1 and linked_id(parms, unit1, key_id, false, clean) or '') .. result .. linked_id(parms, unit2, key_id2, false, '1')			else				result = (unit1 and variable_name(clean, unit1) or '') .. result .. variable_name('1', unit2)			end			if omit_separator(result) then				unit_table.sep = ''			end			return make_link(unit_table.link, result, unit_table)		end		if unit1 then			result = linked_id(parms, unit1, key_id, want_link, clean) .. result			if unit1.sep then				unit_table.sep = unit1.sep			end		elseif omitsep then			unit_table.sep = ''		end		return result .. paren1 .. linked_id(parms, unit2, key_id2, want_link, '1') .. paren2	end	if multiplier then		-- A multiplier (like "100" in "100km") forces the unit to be plural.		multiplier = from_en(multiplier)		if not omitsep then			multiplier = multiplier .. (abbr_on and '&nbsp;' or ' ')		end		if not abbr_on then			if key_id == 'name1' then				key_id = 'name2'			elseif key_id == 'name1_us' then				key_id = 'name2_us'			end		end	else		multiplier = ''	end	local id = unit_table.fixed_name or ((varname and not abbr_on) and variable_name(clean, unit_table) or unit_table[key_id])	if omit_separator(id) then		unit_table.sep = ''	end	if want_link then		local link = data_code.link_exceptions[unit_table.linkey or unit_table.symbol] or unit_table.link		if link then			local before = ''			local i = unit_table.customary			if i == 1 and parms.opt_sp_us then				i = 2  -- show "U.S." not "US"			end			if i == 3 and abbr_on then				i = 4  -- abbreviate "imperial" to "imp"			end			local customary = text_code.customary_units[i]			if customary then				-- LATER: This works for language en only, but it's esoteric so ignore for now.				local pertext				if id:sub(1, 1) == '/' then					-- Want unit "/USgal" to display as "/U.S. gal", not "U.S. /gal".					pertext = '/'					id = id:sub(2)				elseif id:sub(1, 4) == 'per ' then					-- Similarly want "per U.S. gallon", not "U.S. per gallon" (but in practice this is unlikely to be used).					pertext = 'per '					id = id:sub(5)				else					pertext = ''				end				-- Omit any "US"/"U.S."/"imp"/"imperial" from start of id since that will be inserted.				local removes = (i < 3) and { '&nbsp;Mỹ', ' Mỹ' } or { '&nbsp;Anh', ' Anh' }				for _, prefix in ipairs(removes) do					id = mw.ustring.gsub(prefix + "$", "")				end				before = pertext .. make_link(customary.link, customary[1]) .. ' '			end			id = before .. make_link(link, id, unit_table)		end	end	return multiplier .. idendlocal function make_id(parms, which, unit_table)	-- Return id, f where	--   id = unit name or symbol, possibly modified	--   f = true if id is a name, or false if id is a symbol	-- using the value for index 'which', and for 'in' or 'out' (unit_table.inout).	-- Result is '' if no symbol/name is to be used.	-- In addition, set unit_table.sep = ' ' or '&nbsp;' or ''	-- (the separator that caller will normally insert before the id).	if parms.opt_values then		unit_table.sep = ''		return ''	end	local inout = unit_table.inout	local info = unit_table.valinfo[which]	local abbr_org = parms.abbr_org	local adjectival = parms.opt_adjectival	local lk = parms.lk	local want_link = (lk == 'on' or lk == inout)	local usename = unit_table.usename	local singular = info.singular	local want_name	if usename then		want_name = true	else		if abbr_org == nil then			if parms.wantname then				want_name = true			end			if unit_table.usesymbol then				want_name = false			end		end		if want_name == nil then			local abbr = parms.abbr			if abbr == 'on' or abbr == inout or (abbr == 'mos' and inout == 'out') then				want_name = false			else				want_name = true			end		end	end	local key	if want_name then		if lk == nil and unit_table.builtin == 'hand' then			want_link = true		end		if parms.opt_use_nbsp then			unit_table.sep = '&nbsp;'		else			unit_table.sep = ' '		end		if parms.opt_singular then			local value			if inout == 'in' then				value = info.value			else				value = info.absvalue			end			if value then  -- some unusual units do not always set value field				value = abs(value)				singular = (0 < value and value < 1.0001)			end		end		if unit_table.engscale then			-- engscale: so "|1|e3kg" gives "1 thousand kilograms" (plural)			singular = false		end		key = (adjectival or singular) and 'name1' or 'name2'		if parms.opt_sp_us then			key = key .. '_us'		end	else		if unit_table.builtin == 'hand' then			if parms.opt_hand_hh then				unit_table.symbol = 'hh'  -- LATER: might want i18n applied to this			end		end		unit_table.sep = '&nbsp;'		key = parms.opt_sp_us and 'sym_us' or 'symbol'	end	return linked_id(parms, unit_table, key, want_link, info.clean), want_nameendlocal function decorate_value(parms, unit_table, which, number_word)	-- If needed, update unit_table so values will be shown with extra information.	-- For consistency with the old template (but different from fmtpower),	-- the style to display powers of 10 includes "display:none" to allow some	-- browsers to copy, for example, "10³" as "10^3", rather than as "103".	local info	local engscale = unit_table.engscale	local prefix = unit_table.vprefix	if engscale or prefix then		info = unit_table.valinfo[which]		if info.decorated then			return  -- do not redecorate if repeating convert		end		info.decorated = true		if engscale then			local inout = unit_table.inout			local abbr = parms.abbr			if (abbr == 'on' or abbr == inout) and not parms.number_word then				info.show = info.show ..					'<span style="margin-left:0.2em">×<span style="margin-left:0.1em">' ..					from_en('10') ..					'</span></span><s style="display:none">^</s><sup>' ..					from_en(tostring(engscale.exponent)) .. '</sup>'			elseif number_word then				local number_id				local lk = parms.lk				if lk == 'on' or lk == inout then					number_id = make_link(engscale.link, engscale[1])				else					number_id = engscale[1]				end				-- [[:en:WP:NUMERAL]] recommends "&nbsp;" in values like "12 million".				info.show = info.show .. (parms.opt_adjectival and '-' or '&nbsp;') .. number_id			end		end		if prefix then			info.show = prefix .. info.show		end	endendlocal function process_input(parms, in_current)	-- Processing required once per conversion.	-- Return block of text to represent input (value/unit).	if parms.opt_output_only or parms.opt_output_number_only or parms.opt_output_unit_only then		parms.joins = { '', '' }		return ''	end	local first_unit	local composite = in_current.composite  -- nil or table of units	if composite then		first_unit = composite[1]	else		first_unit = in_current	end	local id1, want_name = make_id(parms, 1, first_unit)	local sep = first_unit.sep  -- separator between value and unit, set by make_id	local preunit = parms.preunit1	if preunit then		sep = ''  -- any separator is included in preunit	else		preunit = ''	end	if parms.opt_input_unit_only then		parms.joins = { '', '' }		if composite then			local parts = { id1 }			for i, unit in ipairs(composite) do				if i > 1 then					table.insert(parts, (make_id(parms, 1, unit)))				end			end			id1 = table.concat(parts, ' ')		end		if want_name and parms.opt_adjectival then			return preunit .. hyphenated(id1)		end		return  preunit .. id1	end	if parms.opt_also_symbol and not composite and not parms.opt_flip then		local join1 = parms.joins[1]		if join1 == ' (' or join1 == ' [' then			parms.joins = { ' [' .. first_unit[parms.opt_sp_us and 'sym_us' or 'symbol'] .. ']' .. join1 , parms.joins[2] }		end	end	if in_current.builtin == 'mach' and first_unit.sep ~= '' then  -- '' means omitsep with non-enwiki name		local prefix = id1 .. '&nbsp;'		local range = parms.range		local valinfo = first_unit.valinfo		local result = prefix .. valinfo[1].show		if range then			-- For simplicity and because more not needed, handle one range item only.			local prefix2 = make_id(parms, 2, first_unit) .. '&nbsp;'			result = range_text(range[1], want_name, parms, result, prefix2 .. valinfo[2].show, 'in')		end		return preunit .. result	end	if composite then		-- Simplify: assume there is no range, and no decoration.		local mid = (not parms.opt_flip) and parms.mid or ''		local sep1 = '&nbsp;'		local sep2 = ' '		if parms.opt_adjectival and want_name then			sep1 = '-'			sep2 = '-'		end		if omitsep and sep == '' then			-- Testing the id of the most significant unit should be sufficient.			sep1 = ''			sep2 = ''		end		local parts = { first_unit.valinfo[1].show .. sep1 .. id1 }		for i, unit in ipairs(composite) do			if i > 1 then				table.insert(parts, unit.valinfo[1].show .. sep1 .. (make_id(parms, 1, unit)))			end		end		return table.concat(parts, sep2) .. mid	end	local add_unit = (parms.abbr == 'mos') or		parms[parms.opt_flip and 'out_range_x' or 'in_range_x'] or		(not want_name and parms.abbr_range_x)	local range = parms.range	if range and not add_unit then		unlink(first_unit)	end	local id = range and make_id(parms, range.n + 1, first_unit) or id1	local extra, was_hyphenated = hyphenated_maybe(parms, want_name, sep, id, 'in')	if was_hyphenated then		add_unit = false	end	local result	local valinfo = first_unit.valinfo	if range then		for i = 0, range.n do			local number_word			if i == range.n then				add_unit = false				number_word = true			end			decorate_value(parms, first_unit, i+1, number_word)			local show = valinfo[i+1].show			if add_unit then				show = show .. first_unit.sep .. (i == 0 and id1 or make_id(parms, i+1, first_unit))			end			if i == 0 then				result = show			else				result = range_text(range[i], want_name, parms, result, show, 'in')			end		end	else		decorate_value(parms, first_unit, 1, true)		result = valinfo[1].show	end	return result .. preunit .. extraendlocal function process_one_output(parms, out_current)	-- Processing required for each output unit.	-- Return block of text to represent output (value/unit).	local inout = out_current.inout  -- normally 'out' but can be 'in' for order=out	local id1, want_name = make_id(parms, 1, out_current)	local sep = out_current.sep  -- set by make_id	local preunit = parms.preunit2	if preunit then		sep = ''  -- any separator is included in preunit	else		preunit = ''	end	if parms.opt_output_unit_only then		if want_name and parms.opt_adjectival then			return preunit .. hyphenated(id1)		end		return preunit .. id1	end	if out_current.builtin == 'mach' and out_current.sep ~= '' then  -- '' means omitsep with non-enwiki name		local prefix = id1 .. '&nbsp;'		local range = parms.range		local valinfo = out_current.valinfo		local result = prefix .. valinfo[1].show		if range then			-- For simplicity and because more not needed, handle one range item only.			result = range_text(range[1], want_name, parms, result, prefix .. valinfo[2].show, inout)		end		return preunit .. result	end	local add_unit = (parms[parms.opt_flip and 'in_range_x' or 'out_range_x'] or		(not want_name and parms.abbr_range_x)) and		not parms.opt_output_number_only	local range = parms.range	if range and not add_unit then		unlink(out_current)	end	local id = range and make_id(parms, range.n + 1, out_current) or id1	local extra, was_hyphenated = hyphenated_maybe(parms, want_name, sep, id, inout)	if was_hyphenated then		add_unit = false	end	local result	local valinfo = out_current.valinfo	if range then		for i = 0, range.n do			local number_word			if i == range.n then				add_unit = false				number_word = true			end			decorate_value(parms, out_current, i+1, number_word)			local show = valinfo[i+1].show			if add_unit then				show = show .. out_current.sep .. (i == 0 and id1 or make_id(parms, i+1, out_current))			end			if i == 0 then				result = show			else				result = range_text(range[i], want_name, parms, result, show, inout)			end		end	else		decorate_value(parms, out_current, 1, true)		result = valinfo[1].show	end	if parms.opt_output_number_only then		return result	end	return result .. preunit .. extraendlocal function make_output_single(parms, in_unit_table, out_unit_table)	-- Return true, item where item = wikitext of the conversion result	-- for a single output (which is not a combination or a multiple);	-- or return false, t where t is an error message table.	if parms.opt_order_out and in_unit_table.unitcode == out_unit_table.unitcode then		out_unit_table.valinfo = in_unit_table.valinfo	else		out_unit_table.valinfo = collection()		for _, v in ipairs(in_unit_table.valinfo) do			local success, info = cvtround(parms, v, in_unit_table, out_unit_table)			if not success then return false, info end			out_unit_table.valinfo:add(info)		end	end	return true, process_one_output(parms, out_unit_table)endlocal function make_output_multiple(parms, in_unit_table, out_unit_table)	-- Return true, item where item = wikitext of the conversion result	-- for an output which is a multiple (like 'ftin');	-- or return false, t where t is an error message table.	local inout = out_unit_table.inout  -- normally 'out' but can be 'in' for order=out	local multiple = out_unit_table.multiple  -- table of scaling factors (will not be nil)	local combos = out_unit_table.combination  -- table of unit tables (will not be nil)	local abbr = parms.abbr	local abbr_org = parms.abbr_org	local disp = parms.disp	local want_name = (abbr_org == nil and (disp == 'or' or disp == 'slash')) or						not (abbr == 'on' or abbr == inout or abbr == 'mos')	local want_link = (parms.lk == 'on' or parms.lk == inout)	local mid = parms.opt_flip and parms.mid or ''	local sep1 = '&nbsp;'	local sep2 = ' '	if parms.opt_adjectival and want_name then		sep1 = '-'		sep2 = '-'	end	local do_spell = parms.opt_spell_out	parms.opt_spell_out = nil  -- so the call to cvtround does not spell the value	local function make_result(info, isfirst)		local fmt, outvalue, sign		local results = {}		for i = 1, #combos do			local tfrac, thisvalue, strforce			local out_current = combos[i]			out_current.inout = inout			local scale = multiple[i]			if i == 1 then  -- least significant unit ('in' from 'ftin')				local decimals				out_current.frac = out_unit_table.frac				local success, outinfo = cvtround(parms, info, in_unit_table, out_current)				if not success then return false, outinfo end				if isfirst then					out_unit_table.valinfo = { outinfo }  -- in case output value of first least significant unit is needed				end				sign = outinfo.sign				tfrac = outinfo.fraction_table				if outinfo.is_scientific then					strforce = outinfo.show					decimals = ''				elseif tfrac then					decimals = ''				else					local show = outinfo.show  -- number as a string in local language					local p1, p2 = show:find(numdot, 1, true)					decimals = p1 and show:sub(p2 + 1) or ''  -- text after numdot, if any				end				fmt = '%.' .. ulen(decimals) .. 'f'  -- to reproduce precision				if decimals == '' then					if tfrac then						outvalue = floor(outinfo.raw_absvalue)  -- integer part only; fraction added later					else						outvalue = floor(outinfo.raw_absvalue + 0.5)  -- keep all integer digits of least significant unit					end				else					outvalue = outinfo.absvalue				end			end			if scale then				outvalue, thisvalue = divide(outvalue, scale)			else				thisvalue = outvalue			end			local id			if want_name then				if varname then					local clean					if strforce or tfrac then						clean = '.1'  -- dummy value to force name for floating point					else						clean = format(fmt, thisvalue)					end					id = variable_name(clean, out_current)				else					local key = 'name2'					if parms.opt_adjectival then						key = 'name1'					elseif tfrac then						if thisvalue == 0 then							key = 'name1'						end					elseif parms.opt_singular then						if 0 < thisvalue and thisvalue < 1.0001 then							key = 'name1'						end					else						if thisvalue == 1 then							key = 'name1'						end					end					id = out_current[key]				end			else				id = out_current['symbol']			end			if i == 1 and omit_separator(id) then				-- Testing the id of the least significant unit should be sufficient.				sep1 = ''				sep2 = ''			end			if want_link then				local link = out_current.link				if link then					id = make_link(link, id, out_current)				end			end			local strval			local spell_inout = (i == #combos or outvalue == 0) and inout or ''  -- trick so the last value processed (first displayed) has uppercase, if requested			if strforce and outvalue == 0 then				sign = ''  -- any sign is in strforce				strval = strforce  -- show small values in scientific notation; will only use least significant unit			elseif tfrac then				local wholestr = (thisvalue > 0) and tostring(thisvalue) or nil				strval = format_fraction(parms, spell_inout, false, wholestr, tfrac.numstr, tfrac.denstr, do_spell)			else				strval = (thisvalue == 0) and from_en('0') or with_separator(parms, format(fmt, thisvalue))				if do_spell then					strval = spell_number(parms, spell_inout, strval) or strval				end			end			table.insert(results, strval .. sep1 .. id)			if outvalue == 0 then				break			end			fmt = '%.0f'  -- only least significant unit can have a non-integral value		end		local reversed, count = {}, #results		for i = 1, count do			reversed[i] = results[count + 1 - i]		end		return true, sign .. table.concat(reversed, sep2)	end	local valinfo = in_unit_table.valinfo	local success, result = make_result(valinfo[1], true)	if not success then return false, result end	local range = parms.range	if range then		for i = 1, range.n do			local success, result2 = make_result(valinfo[i+1])			if not success then return false, result2 end			result = range_text(range[i], want_name, parms, result, result2, inout)		end	end	return true, result .. midendlocal function process(parms, in_unit_table, out_unit_table)	-- Return true, s, outunit where s = final wikitext result,	-- or return false, t where t is an error message table.	linked_pages = {}	local success, bad_output	local bad_input_mcode = in_unit_table.bad_mcode  -- nil if input unit is a valid convert unit	local out_unit = parms.out_unit	if out_unit == nil or out_unit == '' or type(out_unit) == 'function' then		if bad_input_mcode or parms.opt_input_unit_only then			bad_output = ''		else			local getdef = type(out_unit) == 'function' and out_unit or get_default			success, out_unit = getdef(in_unit_table.valinfo[1].value, in_unit_table)			parms.out_unit = out_unit			if not success then				bad_output = out_unit			end		end	end	if not bad_output and not out_unit_table then		success, out_unit_table = lookup(parms, out_unit, 'any_combination')		if success then			local mismatch = check_mismatch(in_unit_table, out_unit_table)			if mismatch then				bad_output = mismatch			end		else			bad_output = out_unit_table		end	end	local lhs, rhs	local flipped = parms.opt_flip and not bad_input_mcode	if bad_output then		rhs = (bad_output == '') and '' or message(parms, bad_output)	elseif parms.opt_input_unit_only then		rhs = ''	else		local combos  -- nil (for 'ft' or 'ftin'), or table of unit tables (for 'm ft')		if not out_unit_table.multiple then  -- nil/false ('ft' or 'm ft'), or table of factors ('ftin')			combos = out_unit_table.combination		end		local frac = parms.frac  -- nil or denominator of fraction for output values		if frac then			-- Apply fraction to the unit (if only one), or to non-SI units (if a combination),			-- except that if a precision is also specified, the fraction only applies to			-- the hand unit; that allows the following result:			-- {{convert|156|cm|in hand|1|frac=2}} → 156 centimetres (61.4 in; 15.1½ hands)			-- However, the following is handled elsewhere as a special case:			-- {{convert|156|cm|hand in|1|frac=2}} → 156 centimetres (15.1½ hands; 61½ in)			if combos then				local precision = parms.precision				for _, unit in ipairs(combos) do					if unit.builtin == 'hand' or (not precision and not unit.prefixes) then						unit.frac = frac					end				end			else				out_unit_table.frac = frac			end		end		local outputs = {}		local imax = combos and #combos or 1  -- 1 (single unit) or number of unit tables		if imax == 1 then			parms.opt_order_out = nil  -- only useful with an output combination		end		if not flipped and not parms.opt_order_out then			-- Process left side first so any duplicate links (from lk=on) are suppressed			-- on right. Example: {{convert|28|e9pc|e9ly|abbr=off|lk=on}}			lhs = process_input(parms, in_unit_table)		end		for i = 1, imax do			local success, item			local out_current = combos and combos[i] or out_unit_table			out_current.inout = 'out'			if i == 1 then				if imax > 1 and out_current.builtin == 'hand' then					out_current.out_next = combos[2]  -- built-in hand can influence next unit in a combination				end				if parms.opt_order_out then					out_current.inout = 'in'				end			end			if out_current.multiple then				success, item = make_output_multiple(parms, in_unit_table, out_current)			else				success, item = make_output_single(parms, in_unit_table, out_current)			end			if not success then return false, item end			outputs[i] = item		end		if parms.opt_order_out then			lhs = outputs[1]			table.remove(outputs, 1)		end		local sep = parms.table_joins and parms.table_joins[2] or parms.join_between		rhs = table.concat(outputs, sep)	end	if flipped or not lhs then		local input = process_input(parms, in_unit_table)		if flipped then			lhs = rhs			rhs = input		else			lhs = input		end	end	if parms.join_before then		lhs = parms.join_before .. lhs	end	local wikitext	if bad_input_mcode then		if bad_input_mcode == '' then			wikitext = lhs		else			wikitext = lhs .. message(parms, bad_input_mcode)		end	elseif parms.table_joins then		wikitext = parms.table_joins[1] .. lhs .. parms.table_joins[2] .. rhs	else		wikitext = lhs .. parms.joins[1] .. rhs .. parms.joins[2]	end	if parms.warnings and not bad_input_mcode then		wikitext = wikitext .. parms.warnings	end	return true, get_styles(parms) .. wikitext, out_unit_tableendlocal function main_convert(frame)	-- Do convert, and if needed, do it again with higher default precision.	local parms = { frame = frame }  -- will hold template arguments, after translation	set_config(frame.args)	local success, result = get_parms(parms, frame:getParent().args)	if success then		if type(result) ~= 'table' then			return tostring(result)		end		local in_unit_table = result		local out_unit_table		for _ = 1, 2 do  -- use counter so cannot get stuck repeating convert			success, result, out_unit_table = process(parms, in_unit_table, out_unit_table)			if success and parms.do_convert_again then				parms.do_convert_again = false			else				break			end		end	end	-- If input=x gives a problem, the result should be just the user input	-- (if x is a property like P123 it has been replaced with '').	-- An unknown input unit would display the input and an error message	-- with success == true at this point.	-- Also, can have success == false with a message that outputs an empty string.	if parms.input_text then		if success and not parms.have_problem then			return result		end		local cat		if parms.tracking then			-- Add a tracking category using the given text as the category sort key.			-- There is currently only one type of tracking, but in principle multiple			-- items could be tracked, using different sort keys for convenience.			cat = wanted_category('tracking', parms.tracking)		end		return parms.input_text .. (cat or '')	end	return success and result or message(parms, result)endlocal function _unit(unitcode, options)	-- Helper function for Module:Val to look up a unit.	-- Parameter unitcode must be a string to identify the wanted unit.	-- Parameter options must be nil or a table with optional fields:	--   value = number (for sort key; default value is 1)	--   scaled_top = nil for a normal unit, or a number for a unit which is	--                the denominator of a per unit (for sort key)	--   si = { 'symbol', 'link' }	--                (a table with two strings) to make an SI unit	--                that will be used for the look up	--   link = true if result should be [[linked]]	--   sort = 'on' or 'debug' if result should include a sort key in a	--                span element ('debug' makes the key visible)	--   name = true for the name of the unit instead of the symbol	--   us = true for the US spelling of the unit, if any	-- Return nil if unitcode is not a non-empty string.	-- Otherwise return a table with fields:	--   text = requested symbol or name of unit, optionally linked	--   scaled_value = input value adjusted by unit scale; used for sort key	--   sortspan = span element with sort key like that provided by {{ntsh}},	--     calculated from the result of converting value	--     to a base unit with scale 1.	--   unknown = true if the unitcode was not known	unitcode = strip(unitcode)	if unitcode == nil or unitcode == '' then		return nil	end	set_config({})	linked_pages = {}	options = options or {}	local parms = {		abbr = options.name and 'off' or 'on',		lk = options.link and 'on' or nil,		opt_sp_us = options.us and true or nil,		opt_ignore_error = true,  -- do not add pages using this function to 'what links here' for Module:Convert/extra		opt_sortable_on = options.sort == 'on' or options.sort == 'debug',		opt_sortable_debug = options.sort == 'debug',	}	if options.si then		-- Make a dummy table of units (just one unit) for lookup to use.		-- This makes lookup recognize any SI prefix in the unitcode.		local symbol = options.si[1] or '?'		parms.unittable = { [symbol] = {			_name1 = symbol,			_name2 = symbol,			_symbol = symbol,			utype = symbol,			scale = symbol == 'g' and 0.001 or 1,			prefixes = 1,			default = symbol,			link = options.si[2],		}}	end	local success, unit_table = lookup(parms, unitcode, 'no_combination')	if not success then		unit_table = setmetatable({			symbol = unitcode, name2 = unitcode, utype = unitcode,			scale = 1, default = '', defkey = '', linkey = '' }, unit_mt)	end	local value = tonumber(options.value) or 1	local clean = tostring(abs(value))	local info = {		value = value,		altvalue = value,		singular = (clean == '1'),		clean = clean,		show = clean,	}	unit_table.inout = 'in'	unit_table.valinfo = { info }	local sortspan, scaled_value	if options.sort then		sortspan, scaled_value = make_table_or_sort(parms, value, info, unit_table, options.scaled_top)	end	return {		text = make_id(parms, 1, unit_table),		sortspan = sortspan,		scaled_value = scaled_value,		unknown = not success and true or nil,	}endreturn { convert = main_convert, _unit = _unit }