Module:Lang
--[=[
 
 Lua support for the {{lang}}, {{lang-xx}}, and {{transl}} templates and replacement of various supporting templates. 
 
 ]=]
 
 require('strict');
 
 local initial_style_state;														-- set by lang_xx_normal() and lang_xx_italic()
 
 local getArgs = require ('Module:Arguments').getArgs;
 local unicode = require (&quot;Module:Unicode data&quot;);								-- for is_latin() and is_rtl()
 local yesno = require ('Module:Yesno');
 
 local lang_name_table = mw.loadData ('Module:Language/name/data');
 
 local synonym_table = mw.loadData ('Module:Lang/ISO 639 synonyms');				-- ISO 639-2/639-2T code translation to 639-1 code
 
 local lang_data =  mw.loadData ('Module:Lang/data');							-- language name override and transliteration tool-tip tables
 
 local namespace = mw.title.getCurrentTitle().namespace;							-- used for categorization
 
 local this_wiki_lang = mw.language.getContentLanguage().code;					-- get this wiki's language
 
 local maint_cats = {};															-- maintenance categories go here
 local maint_msgs = {};															-- and their messages go here
 
 
 --[[--------------------------&lt; I S _ S E T &gt;------------------------------------------------------------------
 
 Returns true if argument is set; false otherwise. Argument is 'set' when it exists (not nil) or when it is not an empty string.
 
 ]]
 
 local function is_set( var )
 	return not (var == nil or var == '');
 end
 
 
 --[[--------------------------&lt; I N V E R T  _ I T A L I C S &gt;-------------------------------------------------
 
 This function attempts to invert the italic markup a args.text by adding/removing leading/trailing italic markup
 in args.text.  Like |italic=unset, |italic=invert disables automatic italic markup.  Individual leading/trailing
 apostrophes are converted to their html numeric entity equivalent so that the new italic markup doesn't become
 bold markup inadvertently.
 
 Leading and trailing wiki markup is extracted from args.text into separate table elements.  Addition, removal,
 replacement of wiki markup is handled by a string.gsub() replacement table operating only on these separate elements.
 In the string.gsub() matching pattern, '.*' matches empty string as well as the three expected wiki markup patterns.
 
 This function expects that markup in args.text is complete and correct; if it is not, oddness may result.
 
 ]]
 
 local function invert_italics (source)
 	local invert_pattern_table = {												-- leading/trailing markup add/remove/replace patterns
 		[&quot;&quot;]=&quot;\'\'&quot;,															-- empty string becomes italic markup
 		[&quot;\'\'&quot;]=&quot;&quot;,															-- italic markup becomes empty string
 		[&quot;\'\'\'&quot;]=&quot;\'\'\'\'\'&quot;,												-- bold becomes bold italic
 		[&quot;\'\'\'\'\'&quot;]=&quot;\'\'\'&quot;,												-- bold italic become bold
 		};
 	local seg = {};
 
 	source = source:gsub (&quot;%f[\']\'%f[^\']&quot;, '&amp;#39;');							-- protect single quote marks from being interpreted as bold markup
 
 	seg[1] = source:match ('^(\'\'+%f[^\']).+') or '';							-- get leading markup, if any; ignore single quote
 	seg[3] = source:match ('.+(%f[\']\'\'+)$') or '';							-- get trailing markup, if any; ignore single quote
 
 	if '' ~= seg[1] and '' ~= seg[3] then										-- extract the 'text' 
 		seg[2] = source:match ('^\'\'+%f[^\'](.+)%f[\']\'\'+$')					-- from between leading and trailing markup
 	elseif '' ~= seg[1] then
 		seg[2] = source:match ('^\'\'+%f[^\'](.+)')								-- following leading markup
 	elseif '' ~= seg[3] then
 		seg[2] = source:match ('(.+)%f[\']\'\'+$')								-- preceding trailing markup
 	else
 		seg[2] = source															-- when there is no markup
 	end
 
 	seg[1] = invert_pattern_table[seg[1]] or seg[1];							-- replace leading markup according to pattern table
 	seg[3] = invert_pattern_table[seg[3]] or seg[3];							-- replace leading markup according to pattern table
 
 	return table.concat (seg);													-- put it all back together and done
 end
 
 
 --[[--------------------------&lt; V A L I D A T E _ I T A L I C &gt;------------------------------------------------
 
 validates |italic= or |italics= assigned values.
 
 When |italic= is set and has an acceptible assigned value, return the matching css font-style property value or,
 for the special case 'default', return nil.
 
 When |italic= is not set, or has an unacceptible assigned value, return nil and a nil error message.
 
 When both |italic= and |italics= are set, returns nil and a 'conflicting' error message.
 
 The return value nil causes the calling lang, lang_xx, or transl function to set args.italic according to the template's
 defined default ('inherit' for {{lang}}, 'inherit' or 'italic' for {{lang-xx}} depending on
 the individual template's requirements, 'italic' for {{transl}}) or to the value appropriate to |script=, if set ({{lang}}
 and {{lang-xx}} only).
 
 Accepted values and the values that this function returns are are:
 	nil		-	when |italic= absent or not set; returns nil
 	default	-	for completeness, should rarely if ever be used; returns nil
 	yes		-	force args.text to be rendered in italic font; returns 'italic'
 	no		-	force args.text to be rendered in normal font; returns 'normal'
 	unset	-	disables font control so that font-style applied to text is dictated by markup inside or outside the template; returns 'inherit'
 	invert	-	disables font control so that font-style applied to text is dictated by markup outside or inverted inside the template; returns 'invert'
 
 ]]
 
 local function validate_italic (args)
 	local properties = {['yes'] = 'italic', ['no'] = 'normal', ['unset'] = 'inherit', ['invert'] = 'invert', ['default'] = nil};
 	
 	local count = 0
 	for _, arg in pairs {'italic', 'italics', 'i'} do
 		if args[arg] then
 			count = count + 1
 		end
 	end
 
 	if count &gt; 1 then															-- return nil and an error message if more than one is set 
 		return nil, 'only one of &amp;#124;italic=, &amp;#124;italics=, or &amp;#124;i= can be specified';
 	end
 	
 	return properties[args.italic or args.italics or args.i], nil;				-- return an appropriate value and a nil error message
 end
 
 
 --[=[--------------------------&lt; V A L I D A T E _ C A T _ A R G S &gt;----------------------------------------------------------
 
 Default behavior of the {{lang}} and {{lang-xx}} templates is to add categorization when the templates are used in mainspace.
 This default functionality may be suppressed by setting |nocat=yes or |cat=no.  This function selects one of these two parameters
 to control categorization.
 
 Because having two parameters with 'opposite' names and 'opposite' values is confusing, this function accepts only affirmative
 values for |nocat= and only negative values for |cat=; in both cases the 'other' sense (and non-sense) is not accepted and the
 parameter is treated as if it were not set in the template.
 
 Sets args.nocat to true if categorization is to be turned off; to nil if the default behavior should apply.
 
 Accepted values for |nocat= are the text strings:
 	'yes', 'y', 'true', 't', on, '1'		-- [[Module:Yesno]] returns logical true for all of these; false or nil else
 for |cat=
 	'no', 'n', 'false', 'f', 'off', '0'		-- [[Module:Yesno]] returns logical false for all of these; true or nil else
 
 ]=]
 
 local function validate_cat_args (args)
 	if not (args.nocat or args.cat) then										-- both are nil, so categorize
 		return;
 	end
 	
 	if false == yesno (args.cat) or true == yesno (args.nocat) then
 		args.nocat = true;														-- set to true when args.nocat is affirmative; nil else (as if the parameter were not set in the template)
 	else																		-- args.nocat is the parameter actually used.
 		args.nocat = nil;
 	end
 end
 
 
 --[[--------------------------&lt; I N _ A R R A Y &gt;--------------------------------------------------------------
 
 Whether needle is in haystack
 
 ]]
 
 local function in_array ( needle, haystack )
 	if needle == nil then
 		return false;
 	end
 	for n,v in ipairs( haystack ) do
 		if v == needle then
 			return n;
 		end
 	end
 	return false;
 end
 
 
 --[[--------------------------&lt; F O R M A T _ I E T F _ T A G &gt;------------------------------------------------
 
 prettify ietf tags to use recommended subtag formats:
 	code: lower case
 	script: sentence case
 	region: upper case
 	variant: lower case
 
 ]]
 
 local function format_ietf_tag (code, script, region, variant)
 	local out = {};
 
 	table.insert (out, code:lower());
 	if is_set (script) then
 		script = script:lower():gsub ('^%a', string.upper);
 		table.insert (out, script);
 	end
 
 	if is_set (region) then
 		table.insert (out, region:upper());
 	end
 	
 	if is_set (variant) then
 		table.insert (out, variant:lower());
 	end
 	
 	return table.concat (out, '-');
 end
 
 
 --[[--------------------------&lt; G E T _ I E T F _ P A R T S &gt;--------------------------------------------------
 
 extracts and returns IETF language tag parts:
 	primary language subtag (required) - 2 or 3 character IANA language code
 	script subtag - four character IANA script code
 	region subtag - two-letter or three digit IANA region code
 	variant subtag - four digit or 5-8 alnum variant code
 	private subtag - x- followed by 1-8 alnum private code; only supported with the primary language tag
 
 in any one of these forms
 	lang					lang-variant
 	lang-script				lang-script-variant
 	lang-region				lang-region-variant
 	lang-script-region		lang-script-region-variant
 	lang-x-private	
 	
 each of lang, script, region, variant, and private, when used, must be valid
 
 Languages with both two- and three-character code synonyms are promoted to the two-character synonym because
 the IANA registry file omits the synonymous three-character code; we cannot depend on browsers understanding
 the synonymous three-character codes in the lang= attribute.
 
 For {{lang-xx}} templates, the parameters |script=, |region=, and |variant= are supported (not supported in {{lang}}
 because those parameters are superfluous to the IETF subtags in |code=)
 
 returns six  values; all lower case.  Valid parts are returned as themselves; omitted parts are returned as empty strings, invalid
 parts are returned as nil; the sixth returned item is an error message (if an error detected) or nil.
 
 see http://www.rfc-editor.org/rfc/bcp/bcp47.txt section 2.1
 
 ]]
 
 local function get_ietf_parts (source, args_script, args_region, args_variant)
 	local code, script, region, variant, private;								-- ietf tag parts
 
 	if not is_set (source) then
 		return nil, nil, nil, nil, nil, 'missing language tag';
 	end
 
 	local pattern = {															-- table of tables holding acceptibe ietf tag patterns and short names of the ietf part captured by the pattern
 		{'^(%a%a%a?)%-(%a%a%a%a)%-(%a%a)%-(%d%d%d%d)$', 's', 'r', 'v'}, 				-- 1 -  ll-Ssss-RR-variant (where variant is 4 digits)
 		{'^(%a%a%a?)%-(%a%a%a%a)%-(%d%d%d)%-(%d%d%d%d)$', 's', 'r', 'v'},				-- 2 -  ll-Ssss-DDD-variant (where region is 3 digits; variant is 4 digits)
 		{'^(%a%a%a?)%-(%a%a%a%a)%-(%a%a)%-(%w%w%w%w%w%w?%w?%w?)$', 's', 'r', 'v'},		-- 3 -  ll-Ssss-RR-variant (where variant is 5-8 alnum characters)
 		{'^(%a%a%a?)%-(%a%a%a%a)%-(%d%d%d)%-(%w%w%w%w%w%w?%w?%w?)$', 's', 'r', 'v'},	-- 4 -  ll-Ssss-DDD-variant (where region is 3 digits; variant is 5-8 alnum characters)
 		
 		{'^(%a%a%a?)%-(%a%a%a%a)%-(%d%d%d%d)$', 's', 'v'},						-- 5 -  ll-Ssss-variant (where variant is 4 digits)
 		{'^(%a%a%a?)%-(%a%a%a%a)%-(%w%w%w%w%w%w?%w?%w?)$', 's', 'v'},			-- 6 -  ll-Ssss-variant (where variant is 5-8 alnum characters)
 		
 		{'^(%a%a%a?)%-(%a%a)%-(%d%d%d%d)$', 'r', 'v'},							-- 7 -  ll-RR-variant (where variant is 4 digits)
 		{'^(%a%a%a?)%-(%d%d%d)%-(%d%d%d%d)$', 'r', 'v'},						-- 8 -  ll-DDD-variant (where region is 3 digits; variant is 4 digits)
 		{'^(%a%a%a?)%-(%a%a)%-(%w%w%w%w%w%w?%w?%w?)$', 'r', 'v'},				-- 9 -  ll-RR-variant (where variant is 5-8 alnum characters)
 		{'^(%a%a%a?)%-(%d%d%d)%-(%w%w%w%w%w%w?%w?%w?)$', 'r', 'v'},				-- 10 - ll-DDD-variant (where region is 3 digits; variant is 5-8 alnum characters)
 		
 		{'^(%a%a%a?)%-(%d%d%d%d)$', 'v'},										-- 11 - ll-variant (where variant is 4 digits)
 		{'^(%a%a%a?)%-(%w%w%w%w%w%w?%w?%w?)$', 'v'},							-- 12 - ll-variant (where variant is 5-8 alnum characters)
 		
 		{'^(%a%a%a?)%-(%a%a%a%a)%-(%a%a)$', 's', 'r'},							-- 13 - ll-Ssss-RR
 		{'^(%a%a%a?)%-(%a%a%a%a)%-(%d%d%d)$', 's', 'r'},						-- 14 - ll-Ssss-DDD (region is 3 digits)
 		
 		{'^(%a%a%a?)%-(%a%a%a%a)$', 's'},										-- 15 - ll-Ssss
 		
 		{'^(%a%a%a?)%-(%a%a)$', 'r'},											-- 16 - ll-RR
 		{'^(%a%a%a?)%-(%d%d%d)$', 'r'},											-- 17 - ll-DDD (region is 3 digits)
 		
 		{'^(%a%a%a?)$'},														-- 18 - ll
 		
 		{'^(%a%a%a?)%-x%-(%w%w?%w?%w?%w?%w?%w?%w?)$', 'p'},						-- 19 - ll-x-pppppppp (private is 1-8 alnum characters)
 		}
 
 	local t = {};																-- table of captures; serves as a translator between captured ietf tag parts and named variables
 
 	for i, v in ipairs (pattern) do												-- spin through the pattern table looking for a match
 		local c1, c2, c3, c4;													-- captures in the 'pattern' from the pattern table go here
 	
 		c1, c2, c3, c4 = source:match (pattern[i][1]);							-- one or more captures set if source matches pattern[i])
 			if c1 then															-- c1 always set on match
 				code = c1;														-- first capture is always code
 				t = {
 					[pattern[i][2] or 'x'] = c2,								-- fill the table of captures with the rest of the captures
 					[pattern[i][3] or 'x'] = c3,								-- take index names from pattern table and assign sequential captures
 					[pattern[i][4] or 'x'] = c4,								-- index name may be nil in pattern[i] table so &quot;or 'x'&quot; spoofs a name for this index in this table
 					};
 				script = t.s or '';												-- translate table contents to named variables;
 				region = t.r or '';												-- absent table entries are nil so set named ietf parts to empty string for concatenation
 				variant= t.v or '';
 				private = t.p or '';
 				break;															-- and done
 			end
 	end
 
 	if not code then
 		return nil, nil, nil, nil, nil, table.concat ({'unrecognized language tag: ', source});		-- don't know what we got but it is malformed
 	end
 
 	code = code:lower();														-- ensure that we use and return lower case version of this
 	
 	if not (lang_data.override[code] or lang_name_table.lang[code]) then
 		return nil, nil, nil, nil, nil, table.concat ({'unrecognized language code: ', code});		-- invalid language code, don't know about the others (don't care?)
 	end
 	
 	if synonym_table[code] then													-- if 639-2/639-2T code has a 639-1 synonym
 		table.insert (maint_cats, table.concat ({'Lang and lang-xx code promoted to ISO 639-1|', code}));
 		table.insert (maint_msgs, table.concat ({'code: ', code, ' promoted to code: ', synonym_table[code]}));
 		code = synonym_table[code];												-- use the synonym
 	end
 
 	if is_set (script) then
 		if is_set (args_script) then
 			return code, nil, nil, nil, nil, 'redundant script tag';			-- both code with script and |script= not allowed
 		end
 	else
 		script = args_script or '';												-- use args.script if provided
 	end 
 
 	if is_set (script) then
 		script = script:lower();												-- ensure that we use and return lower case version of this
 		if not lang_name_table.script[script] then
 			return code, nil, nil, nil, nil, table.concat ({'unrecognized script: ', script, ' for code: ', code});	-- language code ok, invalid script, don't know about the others (don't care?)
 		end
 	end
 	if lang_name_table.suppressed[script] then									-- ensure that code-script does not use a suppressed script
 		if in_array (code, lang_name_table.suppressed[script]) then
 			return code, nil, nil, nil, nil, table.concat ({'script: ', script, ' not supported for code: ', code});	-- language code ok, script is suppressed for this code
 		end
 	end
 
 	if is_set (region) then
 		if is_set (args_region) then
 			return code, nil, nil, nil, nil, 'redundant region tag';			-- both code with region and |region= not allowed
 		end
 	else
 		region = args_region or '';												-- use args.region if provided
 	end 
 
 	if is_set (region) then
 		region = region:lower();												-- ensure that we use and return lower case version of this
 		if not lang_name_table.region[region] then
 			return code, script, nil, nil, nil, table.concat ({'unrecognized region: ', region, ' for code: ', code});
 		end
 	end
 	
 	if is_set (variant) then
 		if is_set (args_variant) then
 			return code, nil, nil, nil, nil, 'redundant variant tag';			-- both code with variant and |variant= not allowed
 		end
 	else
 		variant = args_variant or '';											-- use args.variant if provided
 	end 
 
 	if is_set (variant) then
 		variant = variant:lower();												-- ensure that we use and return lower case version of this
 		if not lang_name_table.variant[variant] then							-- make sure variant is valid
 			return code, script, region, nil, nil, table.concat ({'unrecognized variant: ', variant});
 		end																		-- does this duplicate/replace tests in lang() and lang_xx()?
 		if is_set (script) then													-- if script set it must be part of the 'prefix'
 			if not in_array (table.concat ({code, '-', script}), lang_name_table.variant[variant]['prefixes']) then
 				return code, script, region, nil, nil, table.concat ({'unrecognized variant: ', variant, ' for code-script pair: ', code, '-', script});
 			end
 		else
 			if not in_array (code, lang_name_table.variant[variant]['prefixes']) then
 				return code, script, region, nil, nil, table.concat ({'unrecognized variant: ', variant, ' for code: ', code});
 			end				
 		end
 	end
 	
 	if is_set (private) then
 		private = private:lower();												-- ensure that we use and return lower case version of this
 		if not lang_data.override[table.concat ({code, '-x-', private})] then	-- make sure private tag is valid; note that index 
 			return code, script, region, nil, nil, table.concat ({'unrecognized private tag: ', private});
 		end
 	end
 	return code, script, region, variant, private, nil;							-- return the good bits; make sure that msg is nil
 end
 
 
 --[[--------------------------&lt; M A K E _ E R R O R _ M S G &gt;--------------------------------------------------
 
 assembles an error message from template name, message text, help link, and error category.
 
 ]]
 
 local function make_error_msg (msg, args, template)
 	local out = {};
 	local category;
 	
 	if 'transl' == template then
 		category = 'transl';
 	else
 		category = 'lang and lang-xx'
 	end
 	
 	table.insert (out, table.concat ({'&amp;#x5B;', args.text or 'undefined', '&amp;#x5D; '}));	-- for error messages output args.text if available
 	table.insert (out, table.concat ({'&lt;span style=\&quot;font-size:100%; font-style:normal;\&quot; class=\&quot;error\&quot;&gt;error: {{', template, '}}: '}));
 	table.insert (out, msg);
 	table.insert (out, table.concat ({' ([[:பகுப்பு:', category, ' வார்ப்புரு பிழைகள்|உதவி]])'}));
 	table.insert (out, '&lt;/span&gt;');
 	
 	if (0 == namespace) and not args.nocat then						-- only categorize in article space
 		table.insert (out, table.concat ({'[[பகுப்பு:', category, ' வார்ப்புரு பிழைகள்]]'}));
 	end
 
 	return table.concat (out);
 end
 	
 
 --[=[-------------------------&lt; M A K E _ W I K I L I N K &gt;----------------------------------------------------
 
 Makes a wikilink; when both link and display text is provided, returns a wikilink in the form [[L|D]]; if only
 link is provided, returns a wikilink in the form [[L]]; if neither are provided or link is omitted, returns an
 empty string.
 
 ]=]
 
 local function make_wikilink (link, display)
 	if is_set (link) then
 		if is_set (display) then
 			return table.concat ({'[[', link, '|', display, ']]'});
 		else
 			return table.concat ({'[[', link, ']]'});
 		end
 	else
 		return '';
 	end
 end
 
 
 --[[--------------------------&lt; D I V _ M A R K U P _ A D D &gt;--------------------------------------------------
 
 adds &lt;i&gt; and &lt;/i&gt; tags to list-item text or to implied &lt;p&gt;..&lt;/p&gt; text.  mixed not supported
 
 ]]
 
 local function div_markup_add (text, style)
 local implied_p = {};
 
 	if text:find ('^\n[%*:;#]') then											-- look for list markup; list markup must begin at start of text
 		if 'italic' == style then
 			return mw.ustring.gsub (text, '(\n[%*:;#]+)([^\n]+)', '%1&lt;i&gt;%2&lt;/i&gt;');	-- insert italic markup at each list item
 		else
 			return text;
 		end
 	end
 
 	if text:find ('\n+') then													-- look for any number of \n characters in text
 		text = text:gsub ('([^\n])\n([^\n])', '%1 %2');							-- replace single newline characters with a space character which mimics mediawiki
 
 		if 'italic' == style then
 			text = text:gsub('[^\n]+', '&lt;p&gt;&lt;i&gt;%1&lt;/i&gt;&lt;/p&gt;');						-- insert p and italic markup tags at each impled p (two or more consecutive '\n\n' sequences)
 		else
 			text = text:gsub ('[^\n]+', '&lt;p&gt;%1&lt;/p&gt;');							-- insert p markup at each impled p
 			text = text:gsub ('\n', '');										-- strip newline characters
 		end
 	end
 
 	return text;
 end
 
 
 --[[--------------------------&lt; M A K E _ T E X T _ H T M L &gt;--------------------------------------------------
 
 Add the html markup to text according to the type of content that it is: &lt;span&gt; or &lt;i&gt; tags for inline content or
 &lt;div&gt; tags for block content
 
 ]]
 
 local function make_text_html (code, text, tag, rtl, style, size, language)
 	local html = {};
 	local style_added = '';
 
 	if text:match ('^%*') then
 		table.insert (html, '&amp;#42;');											-- move proto language text prefix outside of italic markup if any; use numeric entity because plain splat confuses MediaWiki
 		text = text:gsub ('^%*', '');											-- remove the splat from the text
 	end
 
 	if 'span' == tag then														-- default html tag for inline content
 		if 'italic' == style then												-- but if italic
 			tag = 'i';															-- change to &lt;i&gt; tags
 		end
 	else																		-- must be div so go
 		text = div_markup_add (text, style);									-- handle implied &lt;p&gt;, implied &lt;p&gt; with &lt;i&gt;, and list markup (*;:#) with &lt;i&gt;
 	end
 
 	table.insert (html, table.concat ({'&lt;', tag}));								-- open the &lt;i&gt;, &lt;span&gt;, or &lt;div&gt; html tag
 	table.insert (html, table.concat ({' lang=&quot;', code, '\&quot;'}));				-- add language attribute
 
 	if rtl or unicode.is_rtl(text) then
 		table.insert (html, ' dir=&quot;rtl&quot;');										-- add direction attribute for right to left languages
 	end
 
 	if 'normal' == style then													-- when |italic=no
 		table.insert (html, ' style=\&quot;font-style:normal;');						-- override external markup, if any
 		style_added = '\&quot;';														-- remember that style attribute added and is not yet closed
 	end
 
 	if is_set (size) then														-- when |size=&lt;something&gt;
 		if is_set (style_added) then
 			table.insert (html, table.concat ({' font-size:', size, ';'}));		-- add when style attribute already inserted
 		else
 			table.insert (html, table.concat ({' style=\&quot;font-size:', size, ';'}));	-- create style attribute
 			style_added = '\&quot;';													-- remember that style attribute added and is not yet closed
 		end
 	end
 
 	if is_set (language) then
 		table.insert (html, table.concat ({style_added, ' title=\&quot;', language}));	--start the title text
 		if language:find ('languages') then
 			table.insert (html, ' collective text\&quot;');							-- for collective languages
 		else
 			table.insert (html, ' language text\&quot;');							-- for individual languages
 		end
 		table.insert (html, '&gt;');												-- close the opening html tag
 	else
 		table.insert (html, table.concat ({style_added, '&gt;'}));					-- close the style attribute and close opening html tag
 	end
 	table.insert (html, text);													-- insert the text
 
 	table.insert (html, table.concat ({'&lt;/', tag, '&gt;'}));						-- close the &lt;i&gt;, &lt;span&gt;, or &lt;div&gt; html tag
 
 	if rtl then																	-- legacy; shouldn't be necessary because all of the rtl text is wrapped inside an html tag with dir=&quot;rtl&quot; attribute 
 		table.insert (html, '&amp;lrm;');											-- make sure the browser knows that we're at the end of the rtl
 	end
 	
 	return table.concat (html);													-- put it all together and done
 end
 
 
 --[=[-------------------------&lt; M A K E _ C A T E G O R Y &gt;----------------------------------------------------
 
 For individual language, &lt;language&gt;, returns:
 	[[Category:Articles containing &lt;language&gt;-language text]]
 
 for English:
 	[[Category:Articles containing explicitly cited English-language text]]
 	
 for artificial languages (code: art)
 	[[Category:Articles containing constructed-language text]]
 
 for ISO 639-2 collective languages (and for 639-1 bh):
 	[[Category:Articles with text from the &lt;language&gt; languages collective]]
 
 ]=]
 
 local function make_category (code, language_name, nocat)
 	local cat = {};
 	
 	if (0 ~= namespace) or nocat then											-- only categorize in article space
 		return '';																-- return empty string for concatenation
 	end
 	
 	if language_name:find ('languages') then
 		return table.concat ({'[[பகுப்பு:Articles with text from the ', language_name, ' collective]]'});
 	end
 		
 	table.insert (cat, '[[பகுப்பு:');
 	
 	if 'ta' == code then
 		table.insert (cat, 'வெளிப்படையாக தமிழ் மொழி');
 	elseif 'art' == code then
 		table.insert (cat, 'constructed')
 	else
 		table.insert (cat, language_name);
 	end
 	
 	table.insert (cat, ' வார்த்தைகளைக் கொண்ட கட்டுரைகள்]]');
 
 	return table.concat (cat);	
 end
 
 
 --[[--------------------------&lt; M A K E _ T R A N S L I T &gt;----------------------------------------------------
 
 return translit &lt;i lang=xx-Latn&gt;...&lt;/i&gt; where xx is the language code; else return empty string
 
 The value |script= is not used in {{transl}} for this purpose; instead it uses |code.  Because language scripts
 are listed in the {{transl}} switches they are included in the data tables.  The script parameter is introduced
 at {{Language with name and transliteration}}.  If |script= is set, this function uses it in preference to code.
 
 To avoid confusion, in this module and the templates that use it, the transliteration script parameter is renamed
 to be |translit-script= (in this function, tscript)
 
 This function is used by both lang_xx() and transl()
 	lang_xx() always provides code, language_name, and translit; may provide tscript; never provides style
 	transl() always provides language_name, translit, and one of code or tscript, never both; always provides style
 
 For {{transl}}, style only applies when a language code is provided
 ]]
 
 local function make_translit (code, language_name, translit, std, tscript, style)
 	local title;
 	local tout = {};
 	local title_table = lang_data.translit_title_table;							-- table of transliteration standards and the language codes and scripts that apply to those standards
 	
 	if is_set (code) then														-- when a language code is provided (always with {{lang-xx}} templates, not always with {{transl}})
 		if not style then														-- nil for the default italic style
 			table.insert (tout, &quot;&lt;i lang=\&quot;&quot;);									-- so use &lt;i&gt; tag
 		else
 			table.insert (tout, table.concat ({'&lt;span style=\&quot;font-style:', style, '\&quot; lang=\&quot;'}));	-- non-standard style, construct a span tag for it
 		end
 		table.insert (tout, code);
 		table.insert (tout, &quot;-Latn\&quot; title=\&quot;&quot;);								-- transliterations are always Latin script
 	else
 		table.insert (tout, &quot;&lt;span title=\&quot;&quot;);									-- when no language code: no lang= attribute, not italic ({{transl}} only)
 	end
 	
 	std = std and std:lower();													-- lower case for table indexing
 	
 	if not is_set (std) and not is_set (tscript) then							-- when neither standard nor script specified
 		table.insert (tout, language_name);										-- write a generic tool tip
 		if not language_name:find ('மொழி') then							-- collective language names (plural 'languages' is part of the name)
 			table.insert (tout)									-- skip this text (individual and macro languages only)
 		end
 		table.insert (tout, ' romanization');									-- finish the tool tip; use romanization when neither script nor standard supplied
 	elseif is_set (std) and is_set (tscript) then								-- when both are specified
 		if title_table[std] then												-- and if standard is legitimate
 			if title_table[std][tscript] then									-- and if script for that standard is legitimate
 				table.insert (tout, table.concat ({title_table[std][tscript:lower()], ' (', lang_name_table.script[tscript][1], ' script) transliteration'}));	-- add the appropriate text to the tool tip
 			else
 				table.insert (tout, title_table[std]['default']);				-- use the default if script not in std table; TODO: maint cat? error message because script not found for this standard?
 			end
 		else
 			return '';															-- invalid standard, setup for error message
 		end
 
 	elseif is_set (std) then													-- translit-script not set, use language code
 		if not title_table[std] then return ''; end								-- invalid standard, setup for error message
 		
 		if title_table[std][code] then											-- if language code is in the table (transl may not provide a language code)
 			table.insert (tout, table.concat ({title_table[std][code:lower()], ' (', lang_name_table.lang[code][1], ' language) transliteration'}));	-- add the appropriate text to the tool tip
 		else																	-- code doesn't match
 			table.insert (tout, title_table[std]['default']);					-- so use the standard's default
 		end
 	else																		-- here if translit-script set but translit-std not set
 		if title_table['no_std'][tscript] then
 			table.insert (tout, title_table['no_std'][tscript]);				-- use translit-script if set
 		elseif title_table['no_std'][code] then
 			table.insert (tout, title_table['no_std'][code]);					-- use language code
 		else
 			if is_set (tscript) then
 				table.insert (tout, table.concat ({language_name, '-script transliteration'}));	-- write a script tool tip
 			elseif is_set (code) then
 				if not language_name:find ('மொழி') then					-- collective language names (plural 'languages' is part of the name)
 					table.insert (tout)							-- skip this text (individual and macro languages only)
 				end
 				table.insert (tout, ' transliteration');						-- finish the tool tip
 			else
 				table.insert (tout, ' transliteration');						-- generic tool tip (can we ever get here?)
 			end
 		end
 	end
 
 	table.insert (tout, '&quot;&gt;');
 	table.insert (tout, translit);
 	if is_set (code) and not style then											-- when a language code is provided (always with {{lang-xx}} templates, not always with {{transl}})
 		table.insert (tout, &quot;&lt;/i&gt;&quot;);											-- close the italic tag
 	else
 		table.insert (tout, &quot;&lt;/span&gt;&quot;);											-- no language code so close the span tag
 	end
 	return table.concat (tout);
 end
 
 
 --[[--------------------------&lt; V A L I D A T E _ T E X T &gt;----------------------------------------------------
 
 This function checks the content of args.text and returns empty string if nothing is amiss else it returns an
 error message.  The tests are for empty or missing text and for improper or disallowed use of apostrophe markup.
 
 Italic rendering is controlled by the |italic= template parameter so italic markup should never appear in args.text
 either as ''itself'' or as '''''bold italic''''' unless |italic=unset or |italic=invert.
 
 ]]
 
 local function validate_text (template, args)
 	if not is_set (args.text) then
 		return make_error_msg ('no text', args, template);
 	end
 
 	if args.text:find (&quot;%f[\']\'\'\'\'%f[^\']&quot;) or args.text:find (&quot;\'\'\'\'\'[\']+&quot;) then	-- because we're looking, look for 4 appostrophes or 6+ appostrophes
 		return make_error_msg ('text has malformed markup', args, template);
 	end
 
 	local style = args.italic;
 
 	if ('unset' ~= style) and ('invert' ~=style) then
 		if args.text:find (&quot;%f[\']\'\'%f[^\']&quot;) or args.text:find (&quot;%f[\']\'\'\'\'\'%f[^\']&quot;) then	-- italic but not bold, or bold italic
 			return make_error_msg ('text has italic markup', args, template);
 		end
 	end
 end
 
 
 --[[--------------------------&lt; R E N D E R _ M A I N T &gt;------------------------------------------------------
 
 render mainenance messages and categories
 
 ]]
 
 local function render_maint(nocat)
 	local maint = {};
 	
 	if 0 &lt; #maint_msgs then														-- when there are maintenance messages
 		table.insert (maint, table.concat ({'&lt;span class=&quot;lang-comment&quot; style=&quot;font-style:normal; display:none; color:#33aa33; margin-left:0.3em&quot;&gt;'}));	-- opening &lt;span&gt; tag
 		for _, msg in ipairs (maint_msgs) do
 			table.insert (maint, table.concat ({msg, ' '}));					-- add message strings
 		end
 		table.insert (maint, '&lt;/span&gt;');										-- close the span
 	end
 	
 	if (0 &lt; #maint_cats) and (0 == namespace) and not nocat then				-- when there are maintenance categories; article namespace only
 		for _, cat in ipairs (maint_cats) do
 			table.insert (maint, table.concat ({'[[பகுப்பு:', cat, ']]'}));	-- format and add the categories
 		end
 	end
 	
 	return table.concat (maint);
 end
 
 
 --[[--------------------------&lt; P R O T O _ P R E F I X &gt;------------------------------------------------------
 
 for proto languages, text is prefixed with a splat.  We do that here as a flag for make_text_html() so that a splat
 will be rendered outside of italic markup (if used).  If the first character in text here is already a splat, we
 do nothing
 
 proto_param is boolean or nil; true adds splat prefix regardless of language name; false removes and / or inhibits
 regardless of language name; nil does nothing; presumes that the value in text is correct but removes extra splac
 
 ]]
 
 local function proto_prefix (text, language_name, proto_param)
 	if false == proto_param then												-- when forced by |proto=no
 		return text:gsub ('^%**', '');											-- return text without splat prefix regardless of language name or existing splat prefix in text
 	elseif (language_name:find ('^Proto%-') or (true == proto_param)) then		-- language is a proto or forced by |proto=yes
 		return text:gsub ('^%**', '*');											-- prefix proto-language text with a splat; also removes duplicate prefixing splats
 	end
 	
 	return text:gsub ('^%*+', '*');												-- return text unmolested except multiple splats reduced to one splat
 end
 
 
 --[[--------------------------&lt; H A S _ P O E M _ T A G &gt;------------------------------------------------------
 
 looks for a poem strip marker in text; returns true when found; false else
 
 auto-italic detection disabled when text has poem stripmarker because it is not possible for this code to know
 the content that will replace the stripmarker.
 
 ]]
 
 local function has_poem_tag (text)
 	return text:find ('\127[^\127]*UNIQ%-%-poem%-[%a%d]+%-QINU[^\127]*\127') and true or false;
 end
 
 
 --[[--------------------------&lt; H T M L _ T A G _ S E L E C T &gt;------------------------------------------------
 
 Inspects content of and selectively trims text.  Returns text and the name of an appropriate html tag for text.
 
 If text contains:
 	\n\n	text has implied &lt;p&gt;..&lt;/p&gt; tags - trim leading and trailing whitespace and return 
 If text begins with list markup:
 	\n*		unordered
 	\n;		definition
 	\n:		definition
 	\n#		ordered
 trim all leading whitespace except  \n and trim all trailing whitespace
 
 If text contains &lt;poem&gt;...&lt;/poem&gt; stripmarker, return text unmodified and choose &lt;div&gt;..&lt;/div&gt; tags because 
 the stripmarker is replaced with text wrapped in &lt;div&gt;..&lt;/div&gt; tags.
 
 ]]
 
 local function html_tag_select (text)
 	local tag;
 	
 	if has_poem_tag (text) then													-- contains poem stripmarker (we can't know the content of that)
 		tag = 'div';															-- poem replacement is in div tags so lang must use div tags
 	elseif mw.text.trim (text):find ('\n\n+') then								-- contains implied p tags
 		text = mw.text.trim (text);												-- trim leading and trailing whitespace characters
 		tag = 'div';															-- must be div because span may not contain p tags (added later by MediaWiki); poem replacement is in div tags
 	elseif text:find ('\n[%*:;%#]') then										-- if text has list markup
 		text = text:gsub ('^[\t\r\f ]*', ''):gsub ('%s*$', '');					-- trim all whitespace except leading newline character '\n'
 		tag = 'div';															-- must be div because span may not contain ul, dd, dl, ol tags (added later by MediaWiki)
 	else
 		text = mw.text.trim (text);												-- plain text
 		tag = 'span';															-- so span is fine
 	end
 	
 	return text, tag;
 end
 
 
 --[[--------------------------&lt; V A L I D A T E _ P R O T O &gt;--------------------------------------------------
 
 validates value assigned to |proto=; permitted values are yes and no; yes returns as true, no returns as false,
 empty string (or parameter omitted) returns as nil; any other value returns as nil with a second return value of
 true indicating that some other value has been assigned to |proto=
 
 ]]
 
 local function validate_proto (proto_param)
 	if 'yes' == proto_param then
 		return true;
 	elseif 'no' == proto_param then
 		return false;
 	elseif is_set (proto_param) then
 		return nil, true;														-- |proto= something other than 'yes' or 'no'
 	else
 		return nil;																-- missing or empty
 	end
 end
 
 
 --[[--------------------------&lt; L A N G &gt;----------------------------------------------------------------------
 
 entry point for {{lang}}
 
 there should be no reason to set parameters in the {{lang}} {{#invoke:}}
 	&lt;includeonly&gt;{{#invoke:lang|lang}}&lt;/includeonly&gt;
 
 parameters are received from the template's frame (parent frame)
 
 ]]
 
 local function _lang (args)
 	local out = {};
 	local language_name;														-- used to make category names
 	local subtags = {};															-- IETF subtags script, region, variant, and private
 	local code;																	-- the language code
 	local msg;																	-- for error messages
 	local tag = 'span';															-- initial value for make_text_html()
 	local template = args.template or 'lang';
 
 	if args[1] and args.code then
 		return make_error_msg ('conflicting: {{{1}}} and &amp;#124;code=', args, template);
 	else
 		args.code = args[1] or args.code;										-- prefer args.code
 	end
 
 	if args[2] and args.text then
 		return make_error_msg ('conflicting: {{{2}}} and &amp;#124;text=', args, template);
 	else
 		args.text = args[2] or args.text;										-- prefer args.text
 	end
 	
 	msg = validate_text (template, args);											-- ensure that |text= is set
 	if is_set (msg) then														-- msg is an already-formatted error message
 		return msg;
 	end
 	
 	args.text, tag = html_tag_select (args.text);								-- inspects text; returns appropriate html tag with text trimmed accordingly
 
 	validate_cat_args (args);													-- determine if categorization should be suppressed
 
 	args.rtl = args.rtl == 'yes';												-- convert to boolean: 'yes' -&gt; true, other values -&gt; false
 
 	args.proto, msg = validate_proto (args.proto);								-- return boolean, or nil, or nil and error message flag
 	if msg then
 		return make_error_msg (table.concat ({'invalid &amp;#124;proto=: ', args.proto}), args, template);
 	end
 
 	code, subtags.script, subtags.region, subtags.variant, subtags.private, msg = get_ietf_parts (args.code);	-- |script=, |region=, |variant= not supported because they should be part of args.code ({{{1}}} in {{lang}})
 
 	if msg then
 		return make_error_msg ( msg, args, template);
 	end
 
 	args.italic, msg = validate_italic (args);
 	if msg then
 		return make_error_msg (msg, args, template);
 	end
 
 	if nil == args.italic then													-- nil when |italic= absent or not set or |italic=default; args.italic controls
 		if ('latn' == subtags.script) or								 		-- script is latn
 			(this_wiki_lang ~= code and not is_set (subtags.script) and not has_poem_tag (args.text) and unicode.is_Latin (args.text)) then -- text not this wiki's language, no script specified and not in poem markup but is wholly latn script (auto-italics)
 				args.italic = 'italic';											-- DEFAULT for {{lang}} templates is upright; but if latn script set for font-style:italic
 		else
 			args.italic = 'inherit';											-- italic not set; script not latn; inherit current style
 		end
 	end
 	
 	if is_set (subtags.script) then												-- if script set, override rtl setting
 		if in_array (subtags.script, lang_data.rtl_scripts) then
 			args.rtl = true;													-- script is an rtl script
 		else
 			args.rtl = false;													-- script is not an rtl script
 		end
 	end
 
 	args.code = format_ietf_tag (code, subtags.script, subtags.region, subtags.variant);	-- format to recommended subtag styles; private omitted because private
 
 	subtags.private = subtags.private and table.concat ({code, '-x-', subtags.private}) or nil;		-- assemble a complete private ietf subtag; args.code does not get private subtag
 
 	if is_set (subtags.private) and lang_data.override[subtags.private] then	-- get the language name for categorization
 		language_name = lang_data.override[subtags.private][1];					-- first look for private use tag language name
 	elseif lang_data.override[code] then
 		language_name = lang_data.override[code][1]								-- then language names taken from the override table
 	elseif lang_name_table.lang[code] then
 		language_name = lang_name_table.lang[code][1];							-- table entries sometimes have multiple names, always take the first one
 	end
 
 	if 'invert' == args.italic and 'span' == tag then							-- invert only supported for in-line content
 		args.text = invert_italics (args.text)
 	end
 
 	args.text = proto_prefix (args.text, language_name, args.proto);			-- prefix proto-language text with a splat
 
 	table.insert (out, make_text_html (args.code, args.text, tag, args.rtl, args.italic, args.size, language_name));
 	table.insert (out, make_category (code, language_name, args.nocat));
 	table.insert (out, render_maint(args.nocat));								-- maintenance messages and categories
 
 	return table.concat (out);													-- put it all together and done
 end
 
 
 --[[--------------------------&lt; L A N G &gt;----------------------------------------------------------------------
 
 entry point for {{lang}}
 
 there should be no reason to set parameters in the {{lang}} {{#invoke:}}
 	&lt;includeonly&gt;{{#invoke:lang|lang}}&lt;/includeonly&gt;
 
 parameters are received from the template's frame (parent frame)
 
 ]]
 
 local function lang (frame)
 	local args = getArgs (frame, {												-- this code so that we can detect and handle wiki list markup in text
 		valueFunc = function (key, value)
 			if 2 == key or 'text' == key then									-- the 'text' parameter; do not trim wite space
 				return value;													-- return untrimmed 'text'
 			elseif value then													-- all other values: if the value is not nil
 				value = mw.text.trim (value);									-- trim whitespace
 				if '' ~= value then												-- empty string when value was only whitespace
 					return value;
 				end
 			end
 			return nil;															-- value was empty or contained only whitespace
 		end																		-- end of valueFunc
 		});
 
 	return _lang (args);
 end
 
 
 --[[--------------------------&lt; L A N G _ X X &gt;----------------------------------------------------------------
 
 For the {{lang-xx}} templates, the only parameter required to be set in the template is the language code.  All
 other parameters can, usually should, be written in the template call.  For {{lang-xx}} templates for languages
 that can have multiple writing systems, it may be appropriate to set |script= as well.
 
 For each {{lang-xx}} template choose the appropriate entry-point function so that this function knows the default
 styling that should be applied to text.
 
 For normal, upright style:
 	&lt;includeonly&gt;{{#invoke:lang|lang_xx_inherit|code=xx}}&lt;/includeonly&gt;
 For italic style:
 	&lt;includeonly&gt;{{#invoke:lang|lang_xx_italic|code=xx}}&lt;/includeonly&gt;
 
 All other parameters should be received from the template's frame (parent frame)
 
 Supported parameters are:
 	|code = (required) the IANA language code
 	|script = IANA script code; especially for use with languages that use multiple writing systems
 	|region = IANA region code
 	|variant = IANA variant code
 	|text = (required) the displayed text in language specified by code
 	|link = boolean false ('no') does not link code-spcified language name to associated language article
 	|rtl = boolean true ('yes') identifies the language specified by code as a right-to-left language
 	|nocat = boolean true ('yes') inhibits normal categorization; error categories are not affected
 	|cat = boolian false ('no') opposite form of |nocat=
 	|italic = boolean true ('yes') renders displayed text in italic font; boolean false ('no') renders displayed text in normal font; not set renders according to initial_style_state
 	|lit = text that is a literal translation of text
 	|label = 'none' to suppress all labeling (language name, 'translit.', 'lit.')
 				any other text replaces language-name label - automatic wikilinking disabled
 	
 	for those {{lang-xx}} templates that support transliteration (those templates where |text= is not entirely latn script):
 	|translit = text that is a transliteration of text
 	|translit-std = the standard that applies to the transliteration
 	|translit-script = ISO 15924 script name; falls back to code
 
 For {{lang-xx}}, the positional parameters are:
 	{{{1}}}	text
 	{{{2}}}	transliterated text
 	{{{3}}}	literal translation text
 no other positional parameters are allowed
 
 ]]
 
 local function _lang_xx (args)
 	local out = {};
 	local language_name;														-- used to make display text, article links
 	local category_name;														-- same as language_name except that it retains any parenthetical disambiguators (if any) from the data set
 	local subtags = {};															-- IETF subtags script, region, and variant
 	local code;																	-- the language code
 
 	local translit_script_name;													-- name associated with IANA (ISO 15924) script code
 	local translit;
 	local translit_title;
 	local msg;																	-- for error messages
 	local tag = 'span';															-- initial value for make_text_html()
 	local template = args.template or 'lang-xx';
 
 	if args[1] and args.text then
 		return make_error_msg ('conflicting: {{{1}}} and &amp;#124;text=', args, template);
 	else
 		args.text = args[1] or args.text;										-- prefer args.text
 	end
 	
 	msg = validate_text (template, args);										-- ensure that |text= is set, does not contain italic markup and is protected from improper bolding
 	if is_set (msg) then
 		return msg;
 	end
 
 	args.text, tag = html_tag_select (args.text);								-- inspects text; returns appropriate html tag with text trimmed accordingly
 
 	if args[2] and args.translit then
 		return make_error_msg ('conflicting: {{{2}}} and &amp;#124;translit=', args, template);
 	else
 		args.translit = args[2] or args.translit								-- prefer args.translit
 	end
 	
 	if args[3] and (args.translation or args.lit) then
 		return make_error_msg ('conflicting: {{{3}}} and &amp;#124;lit= or &amp;#124;translation=', args, template);
 	elseif args.translation and args.lit then
 		return make_error_msg ('conflicting: &amp;#124;lit= and &amp;#124;translation=', args, template);
 	else
 		args.translation = args[3] or args.translation or args.lit;				-- prefer args.translation
 	end
 
 	if args.links and args.link then
 		return make_error_msg ('conflicting: &amp;#124;links= and &amp;#124;link=', args, template);
 	else
 		args.link = args.link or args.links;									-- prefer args.link
 	end
 
 	validate_cat_args (args);													-- determine if categorization should be suppressed
 
 	args.rtl = args.rtl == 'yes';												-- convert to boolean: 'yes' -&gt; true, other values -&gt; false
 
 	code, subtags.script, subtags.region, subtags.variant, subtags.private, msg = get_ietf_parts (args.code, args.script, args.region, args.variant);	-- private omitted because private
 
 	if msg then																	-- if an error detected then there is an error message
 		return make_error_msg (msg, args, template);
 	end
 	
 	args.italic, msg = validate_italic (args);
 	if msg then
 		return make_error_msg (msg, args, template);
 	end
 
 	if nil == args.italic then													-- args.italic controls
 		if is_set (subtags.script) then
 			if 'latn' == subtags.script then
 				args.italic = 'italic';											-- |script=Latn; set for font-style:italic
 			else
 				args.italic = initial_style_state;								-- italic not set; script is not latn; set for font-style:&lt;initial_style_state&gt;
 			end
 		else
 			args.italic = initial_style_state;									-- here when |italic= and |script= not set; set for font-style:&lt;initial_style_state&gt;
 		end
 	end
 	
 	if is_set (subtags.script) then												-- if script set override rtl setting
 		if in_array (subtags.script, lang_data.rtl_scripts) then
 			args.rtl = true;													-- script is an rtl script
 		else
 			args.rtl = false;													-- script is not an rtl script
 		end
 	end
 
 	args.proto, msg = validate_proto (args.proto);								-- return boolean, or nil, or nil and error message flag
 	if msg then
 		return make_error_msg (table.concat ({'invalid &amp;#124;proto=: ', args.proto}), args, template);
 	end
 
 	args.code = format_ietf_tag (code, subtags.script, subtags.region, subtags.variant);	-- format to recommended subtag styles
 	
 	subtags.private = subtags.private and table.concat ({code, '-x-', subtags.private}) or nil;		-- assemble a complete private ietf subtag; args.code does not get private subtag
 
 	if is_set (subtags.private) and lang_data.override[subtags.private] then	-- get the language name for categorization
 		language_name = lang_data.override[subtags.private][1];					-- first look for private use tag language name
 	elseif lang_data.override[args.code:lower()] then							-- look for whole IETF tag in override table
 		language_name = lang_data.override[args.code:lower()][1];				-- args.code:lower() because format_ietf_tag() returns mixed case
 	elseif lang_data.override[code] then										-- not there so try basic language code
 		language_name = lang_data.override[code][1];
 	elseif not is_set (subtags.variant) then									
 		if lang_name_table.lang[code] then
 			language_name = lang_name_table.lang[code][1];						-- table entries sometimes have multiple names, always take the first one
 		end
 	else																		-- TODO: is this the right thing to do: take language display name from variants table?
 		if lang_name_table.variant[subtags.variant] then						-- TODO: there is some discussion at Template talk:Lang about having a label parameter for use when variant name is not desired among other things
 			language_name = lang_name_table.variant[subtags.variant]['descriptions'][1];	-- table entries sometimes have multiple names, always take the first one
 		end
 	end
 
 	category_name = language_name;												-- category names retain IANA parenthetical diambiguators (if any)
 	language_name = language_name:gsub ('%s+%b()', '');							-- remove IANA parenthetical disambiguators or qualifiers from names that have them
 
 	if args.label then
 		if 'none' ~= args.label then
 			table.insert (out, table.concat ({args.label, ': '}));				-- custom label
 		end
 	else
 		if 'no' == args.link then
 			table.insert (out, language_name);									-- language name without wikilink
 		else
 			if language_name:find ('மொழி') then
 				table.insert (out, make_wikilink (language_name));				-- collective language name uses simple wikilink
 			elseif lang_data.article_name[code] then
 				table.insert (out, make_wikilink (lang_data.article_name[code][1], language_name));	-- language name with wikilink from override data
 			else
 				table.insert (out, make_wikilink (language_name));	-- language name with wikilink
 			end
 		end
 		table.insert (out, ': ');												-- separator
 	end
 
 	if 'invert' == args.italic then
 		args.text = invert_italics (args.text)
 	end
 	
 	args.text = proto_prefix (args.text, language_name, args.proto);			-- prefix proto-language text with a splat
 
 	table.insert (out, make_text_html (args.code, args.text, tag, args.rtl, args.italic, args.size))
 
 	if is_set (args.translit) and not unicode.is_Latin (args.text) then			-- transliteration (not supported in {{lang}}); not supported when args.text is wholly latn text (this is an imperfect test)
 		table.insert (out, ', ');												-- comma to separate text from translit
 		if 'none' ~= args.label then
 			table.insert (out, '&lt;small&gt;');
 			if lang_name_table.script[args['translit-script']] then				-- when |translit-script= is set, try to use the script's name
 				translit_script_name = lang_name_table.script[args['translit-script'][1]];
 			else
 				translit_script_name = language_name;							-- fall back on language name
 			end
 			translit_title = mw.title.makeTitle (0, table.concat ({'Romanization of ', translit_script_name}));		-- make a title object
 			if translit_title.exists and ('no' ~= args.link) then
 				table.insert (out, make_wikilink ('Romanization of ' .. translit_script_name or language_name, 'romanized') .. ':');	-- make a wikilink if there is an article to link to
 			else
 				table.insert (out, 'romanized:');								-- else plain text
 			end
 			table.insert (out, '&amp;nbsp;&lt;/small&gt;');								-- close the small tag
 		end
 		
 		translit = make_translit (args.code, language_name, args.translit, args['translit-std'], args['translit-script'])
 		if is_set (translit) then
 			table.insert (out, translit);
 		else
 			return make_error_msg (table.concat ({'invalid translit-std: \'', args['translit-std'] or '[missing]'}), args, template);
 		end
 	end
 	
 	if is_set (args.translation) then											-- translation (not supported in {{lang}})
 		table.insert (out, ', ');
 		if 'none' ~= args.label then
 			table.insert (out, '&lt;small&gt;');
 			if 'no' == args.link then
 				table.insert (out, '&lt;abbr title=&quot;literal translation&quot;&gt;lit.&lt;/abbr&gt;');
 			else
 				table.insert (out, make_wikilink ('Literal translation', 'lit.'));
 			end
 			table.insert (out, &quot;&amp;nbsp;&lt;/small&gt;&quot;);
 		end
 		table.insert (out, table.concat ({'&amp;#39;', args.translation, '&amp;#39;'}));	-- use html entities to avoid wiki markup confusion
 	end
 	
 	table.insert (out, make_category (code, category_name, args.nocat));
 	table.insert (out, render_maint(args.nocat));								-- maintenance messages and categories
 
 	return table.concat (out);													-- put it all together and done
 end
 
 
 --[[--------------------------&lt; L A N G _ X X _ A R G S _ G E T &gt;----------------------------------------------
 
 common function to get args table from {{lang-??}} templates
 
 returns table of args
 
 ]]
 
 local function lang_xx_args_get (frame)
 	local args = getArgs(frame,
 		{
 		parentFirst= true,														-- parameters in the template override parameters set in the {{#invoke:}}
 		valueFunc = function (key, value)
 			if 1 == key then													-- the 'text' parameter; do not trim wite space
 				return value;													-- return untrimmed 'text'
 			elseif value then													-- all other values: if the value is not nil
 				value = mw.text.trim (value);									-- trim whitespace
 				if '' ~= value then												-- empty string when value was only whitespace
 					return value;
 				end
 			end
 			return nil;															-- value was empty or contained only whitespace
 		end																		-- end of valueFunc
 	});
 
 	return args;
 end
 
 
 --[[--------------------------&lt; L A N G _ X X _ I T A L I C &gt;--------------------------------------------------
 
 Entry point for those {{lang-xx}} templates that call lang_xx_italic().  Sets the initial style state to italic.
 
 ]]
 
 local function lang_xx_italic (frame)
 	local args = lang_xx_args_get (frame);
 	
 	initial_style_state = 'italic';
 	return _lang_xx (args);
 end
 
 
 --[[--------------------------&lt; _ L A N G _ X X _ I T A L I C &gt;------------------------------------------------
 
 Entry point ffrom another module.  Sets the initial style state to italic.
 
 ]]
 
 local function _lang_xx_italic (args)
 	initial_style_state = 'italic';
 	return _lang_xx (args);
 end
 
 
 --[[--------------------------&lt; L A N G _ X X _ I N H E R I T &gt;------------------------------------------------
 
 Entry point for those {{lang-xx}} templates that call lang_xx_inherit().  Sets the initial style state to inherit.
 
 ]]
 
 local function lang_xx_inherit (frame)
 	local args = lang_xx_args_get (frame);
 
 	initial_style_state = 'inherit';
 	return _lang_xx (args);
 end
 
 
 --[[--------------------------&lt; _ L A N G _ X X _ I N H E R I T &gt;----------------------------------------------
 
 Entry point from another module.  Sets the initial style state to inherit.
 
 ]]
 
 local function _lang_xx_inherit (args)
 	initial_style_state = 'inherit';
 	return _lang_xx (args);
 end
 
 
 --[[--------------------------&lt; _ I S _ I E T F _ T A G &gt;------------------------------------------------------
 
 Returns true when a language name associated with IETF language tag exists; nil else.  IETF language tag must be valid.
 
 All code combinations supported by {{lang}} and the {{lang-xx}} templates are supported by this function.
 
 The purpose of this function is to replace {{#ifexist:Template:ISO 639 name xx|&lt;exists&gt;|&lt;does not exist&gt;}} in
 templates that are better served by using {{#invoke:lang|name_from_tag|&lt;code&gt;}}
 
 Module entry point from another module
 
 ]]
 
 local function _is_ietf_tag (tag)												-- entry point when this module is require()d into another
 	local c, s, r, v, p, err;													-- code, script, region, private, error message
 	
 	c, s, r, v, p, err = get_ietf_parts (tag);									-- disassemble tag into constituent part and validate
 	return ((c and not err) and true) or nil;									-- return true when code portion has a value without error message; nil else
 end
 
 
 --[[--------------------------&lt; I S _ I E T F _ T A G &gt;--------------------------------------------------------
 
 Module entry point from an {{#invoke:}}
 
 ]]
 
 local function is_ietf_tag (frame)												-- entry point from an {{#invoke:Lang|is_ietf_tag|&lt;ietf tag&gt;}}
 	return _is_ietf_tag (frame.args[1]);										-- frame.args[1] is the ietf language tag
 end
 
 
 --[[--------------------------&lt; _ N A M E _ F R O M _ C O D E &gt;------------------------------------------------
 
 Returns language name associated with IETF language tag if valid; empty string else.
 
 All code combinations supported by {{lang}} and the {{lang-xx}} templates are supported by this function.
 
 Set invoke's |link= parameter to yes to get wikilinked version of the language name.
 
 Module entry point from another module
 
 ]]
 
 local function _name_from_tag (args)
 	local subtags = {};															-- IETF subtags script, region, variant, and private
 	local raw_code = args[1];													-- save a copy of the input IETF subtag
 	local link = 'yes' == args['link'];											-- make a boolean
 	local code;																	-- the language code
 	local msg;																	-- gets an error message if IETF language tag is malformed or invalid
 	local language_name = '';
 	
 	code, subtags.script, subtags.region, subtags.variant, subtags.private, msg = get_ietf_parts (raw_code);
 	if msg then
 		local template = (args['template'] and table.concat ({'{{', args['template'], '}}: '})) or '';	-- make template name (if provided by the template)
 		return table.concat ({'&lt;span style=\&quot;font-size:100%; font-style:normal;\&quot; class=\&quot;error\&quot;&gt;error: ', template, msg, '&lt;/span&gt;'});
 	end
 
 	if lang_data.override[raw_code:lower()] then								-- look for whole IETF tag in override table (force lower case)
 		language_name = lang_data.override[raw_code:lower()][1];
 	elseif lang_data.override[code] then										-- not there so try basic language code in override table
 		language_name = lang_data.override[code][1];
 	elseif not is_set (subtags.variant) then									
 		if lang_name_table.lang[code] then
 			language_name = lang_name_table.lang[code][1];						-- table entries sometimes have multiple names, always take the first one
 		end
 	else																		-- TODO: is this the right thing to do: take language display name from variants table?
 		if lang_name_table.variant[subtags.variant] then						-- TODO: there is some discussion at Template talk:Lang about having a label parameter for use when variant name is not desired among other things
 			language_name = lang_name_table.variant[subtags.variant]['descriptions'][1];	-- table entries sometimes have multiple names, always take the first one
 		end
 	end
 
 	language_name = language_name:gsub ('%s+%b()', '');							-- remove IANA parenthetical disambiguators or qualifiers from names that have them
 
 	if link then																-- when |link=yes, wikilink the language name
 		if language_name:find ('மொழி') then
 			return make_wikilink (language_name);								-- collective language name uses simple wikilink
 		elseif lang_data.article_name[code] then
 			return make_wikilink (lang_data.article_name[code][1], language_name);	-- language name with wikilink from override data
 		else
 			return make_wikilink (language_name);	-- language name with wikilink
 		end
 	end
 
 	return language_name;
 
 end
 
 
 --[[--------------------------&lt; N A M E _ F R O M _ C O D E &gt;--------------------------------------------------
 
 Module entry point from an {{#invoke:}}
 
 ]]
 
 local function name_from_tag (frame)											-- entry point from an {{#invoke:Lang|name_from_tag|&lt;ietf tag&gt;|link=&lt;yes&gt;|template=&lt;template name&gt;}}
 	return _name_from_tag (frame.args);											-- pass-on the args table, nothing else
 end
 
 
 --[[--------------------------&lt; _ T A G _ F R O M _ N A M E &gt;--------------------------------------------------
 
 Returns the ietf language tag associated with the language name.  Spelling of language name must be correct
 according to the spelling in the source tables.  When a standard language name has a parenthetical disambiguator,
 that disambiguator must be omitted (they are not present in the data name-to-tag tables).
 
 Module entry point from another module
 
 ]]
 
 local function _tag_from_name (args)											-- entry point from another module
 	local msg;
 
 	if args[1] and '' ~= args[1] then
 		local data = mw.loadData ('Module:Lang/name to tag');					-- get the reversed data tables
 		local lang = args[1]:lower();											-- allow any-case for the language name (speeling must till be correct)
 		local tag = data.rev_lang_data[lang] or data.rev_lang_name_table[lang];-- get the code; look first in the override then in the standard
 
 		if tag then
 			return tag;															-- language name found so return tag and done
 		else
 			msg = 'language: ' .. args[1] .. ' not found'						-- language name not found, error message
 		end
 	else
 		msg = 'missing language name'											-- language name not provided, error message
 	end
 
 	local template = '';
 	if args.template and '' ~= args.template then
 		template = table.concat ({'{{', args['template'], '}}: '});				-- make template name (if provided by the template)
 	end
 	return table.concat ({'&lt;span style=\&quot;font-size:100%; font-style:normal;\&quot; class=\&quot;error\&quot;&gt;error: ', template, msg, '&lt;/span&gt;'});
 end
 
 
 --[[--------------------------&lt; T A G _ F R O M _ N A M E &gt;----------------------------------------------------
 
 Module entry point from an {{#invoke:}}
 
 ]]
 
 local function tag_from_name (frame)											-- entry point from an {{#invoke:Lang|tag_from_name|&lt;language name&gt;|link=&lt;yes&gt;|template=&lt;template name&gt;}}
 	return _tag_from_name (frame.args);											-- pass-on the args table, nothing else
 end
 
 
 --[[--------------------------&lt; _ T R A N S L &gt;----------------------------------------------------------------
 
 Module entry point from another module
 
 ]]
 
 local function _transl (args)
 	local title_table = lang_data.translit_title_table;							-- table of transliteration standards and the language codes and scripts that apply to those standards
 	local language_name;														-- language name that matches language code; used for tool tip
 	local translit;																-- translitterated text to display
 	local script;																-- IANA script
 	local msg;																	-- for when called functions return an error message
 
 	if is_set (args[3]) then													-- [3] set when {{transl|code|standard|text}}
 		args.text = args[3];													-- get the transliterated text
 		args.translit_std = args[2] and args[2]:lower();						-- get the standard; lower case for table indexing
 
 		if not title_table[args.translit_std] then
 			return make_error_msg (table.concat ({'unrecognized transliteration standard: ', args.translit_std}), args, 'transl');
 		end
 	else
 		if is_set (args[2]) then												-- [2] set when {{transl|code|text}}
 			args.text = args[2];												-- get the transliterated text
 		else
 			if args[1] and args[1]:match ('^%a%a%a?%a?$') then					-- args[2] missing; is args[1] a code or its it the transliterated text?
 				return make_error_msg ('no text', args, 'transl');				-- args[1] is a code so we're missing text
 			else
 				args.text = args[1];											-- args[1] is not a code so we're missing that; assign args.text for error message
 				return make_error_msg ('missing language / script code', args, 'transl');
 			end
 		end
 	end
 
 	if is_set (args[1]) then													-- IANA language code used for html lang= attribute; or ISO 15924 script code
 		if args[1]:match ('^%a%a%a?%a?$') then									-- args[1] has correct form?
 			args.code = args[1]:lower();										-- use the language/script code; only (2, 3, or 4 alpha characters); lower case because table indexes are lower case
 		else
 			return make_error_msg (table.concat ({'unrecognized language / script code: ', args[1]}), args, 'transl');	-- invalid language / script code
 		end
 	else
 		return make_error_msg ('missing language / script code', args, 'transl');			-- missing language / script code so quit
 	end
 
 	args.italic, msg = validate_italic (args);
 	if msg then
 		return make_error_msg (msg, args, 'transl');
 	end
 	
 	if 'italic' == args.italic then												-- 'italic' when |italic=yes; because that is same as absent or not set and |italic=default
 		args.italic = nil;														-- set to nil; 
 	end
 
 	if lang_data.override[args.code] then										-- is code a language code defined in the override table?
 		language_name = lang_data.override[args.code][1];
 	elseif lang_name_table.lang[args.code] then									-- is code a language code defined in the standard language code tables?
 		language_name = lang_name_table.lang[args.code][1];
 	elseif lang_name_table.script[args.code] then								-- if here, code is not a language code; is it a script code?
 		language_name = lang_name_table.script[args.code][1];
 		script = args.code;														-- code was an ISO 15924 script so use that instead
 		args.code = '';															-- unset because not a language code
 	else
 		return make_error_msg (table.concat ({'unrecognized language / script code: ', args.code}), args, 'transl');	-- invalid language / script code
 	end
 																				-- here only when all parameters passed to make_translit() are valid
 	return make_translit (args.code, language_name, args.text, args.translit_std, script, args.italic);
 end
 
 
 --[[--------------------------&lt; T R A N S L &gt;------------------------------------------------------------------
 
 Module entry point from an {{#invoke:}}
 
 ]]
 
 local function transl (frame)
 	local args = getArgs(frame);												-- no {{#invoke:}} parameters
 	return _transl (args);
 end
 
 
 --[[--------------------------&lt; E X P O R T E D   F U N C T I O N S &gt;------------------------------------------
 ]]
 
 return {
 	lang = lang,																-- entry point for {{lang}}
 	lang_xx_inherit = lang_xx_inherit,											-- entry points for {{lang-??}}
 	lang_xx_italic = lang_xx_italic,
 	is_ietf_tag = is_ietf_tag,
 	tag_from_name = tag_from_name,												-- returns ietf tag associated with language name
 	name_from_tag = name_from_tag,												-- used for template documentation; possible use in ISO 639 name from code templates
 	transl = transl,															-- entry point for {{transl}}
 
 	_lang = _lang,																-- entry points when this module is require()d into other modules
 	_lang_xx_inherit = _lang_xx_inherit,
 	_lang_xx_italic = _lang_xx_italic,
 	_is_ietf_tag = _is_ietf_tag,
 	_tag_from_name = _tag_from_name, 
 	_name_from_tag = _name_from_tag,
 	_transl = _transl,