--[=[



Lua support for the {{lang}}, {{lang-xx}}, and {{transliteration}} templates and replacement of various supporting templates. 



]=]



require('strict');



local getArgs = require ('Module:Arguments').getArgs;

local unicode = require ("Module:Unicode data");								-- for is_latin() and is_rtl()

local yesno = require ('Module:Yesno');



local lang_data =  mw.loadData ('Module:Lang/data');							-- language name override and transliteration tool-tip tables

local lang_name_table = lang_data.lang_name_table;								-- language codes, names, regions, scripts, suppressed scripts

local lang_table = lang_data.lang_name_table.lang;

local lang_dep_table = lang_data.lang_name_table.lang_dep;

local script_table = lang_data.lang_name_table.script;

local region_table = lang_data.lang_name_table.region;

local variant_table = lang_data.lang_name_table.variant;

local suppressed_table = lang_data.lang_name_table.suppressed;

local override_table = lang_data.override;



local synonym_table = mw.loadData ('Module:Lang/ISO 639 synonyms');				-- ISO 639-2/639-2T code translation to 639-1 code



local namespace = mw.title.getCurrentTitle().namespace;							-- used for categorization



local content_lang = mw.language.getContentLanguage();

local this_wiki_lang_tag = content_lang.code;									-- get this wiki's language tag

local this_wiki_lang_dir = content_lang:getDir();								-- get this wiki's language direction



local initial_style_state;														-- set by lang_xx_normal() and lang_xx_italic()



local maint_cats = {};															-- maintenance categories go here

local maint_msgs = {};															-- and their messages go here





--[[--------------------------< I S _ S E T >------------------------------------------------------------------



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





--[[--------------------------< I N V E R T  _ I T A L I C S >-------------------------------------------------



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

		""="\'\'",															-- empty string becomes italic markup

		"\'\'"="",															-- italic markup becomes empty string

		"\'\'\'"="\'\'\'\'\'",												-- bold becomes bold italic

		"\'\'\'\'\'"="\'\'\'",												-- bold italic become bold

		};

	local seg = {};



	source = source:gsub ("%f[\'\'%f[^\']", '&#39;');							-- protect single quote marks from being interpreted as bold markup



	seg1 = source:match ('^(\'\'+%f[^\']).+') or '';							-- get leading markup, if any; ignore single quote

	seg3 = source:match ('.+(%f[\'\'\'+)$') or '';							-- get trailing markup, if any; ignore single quote



	if '' ~= seg1 and '' ~= seg3 then										-- extract the 'text' 

		seg2 = source:match ('^\'\'+%f[^\'](.+)%f[\'\'\'+$')					-- from between leading and trailing markup

	elseif '' ~= seg1 then

		seg2 = source:match ('^\'\'+%f[^\'](.+)')								-- following leading markup

	elseif '' ~= seg3 then

		seg2 = source:match ('(.+)%f[\'\'\'+$')								-- preceding trailing markup

	else

		seg2 = source															-- when there is no markup

	end



	seg1 = invert_pattern_tableseg1]] or seg1];							-- replace leading markup according to pattern table

	seg3 = invert_pattern_tableseg3]] or seg3];							-- replace leading markup according to pattern table



	return table.concat (seg);													-- put it all back together and done

end





--[[--------------------------< V A L I D A T E _ I T A L I C >------------------------------------------------



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 {{transliteration}}) 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 argsarg then

			count = count + 1

		end

	end



	if count > 1 then															-- return nil and an error message if more than one is set 

		return nil, 'only one of |italic=, |italics=, or |i= can be specified';

	end

	

	return propertiesargs.italic or args.italics or args.i], nil;				-- return an appropriate value and a nil error message

end





--[=[--------------------------< V A L I D A T E _ C A T _ A R G S >----------------------------------------------------------



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





--[[--------------------------< I N _ A R R A Y >--------------------------------------------------------------



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





--[[--------------------------< F O R M A T _ I E T F _ T A G >------------------------------------------------



prettify ietf tags to use recommended subtag formats:

	code: lower case

	script: sentence case

	region: upper case

	variant: lower case

	private: lower case prefixed with -x-

	

]]



local function format_ietf_tag (code, script, region, variant, private)

	local out = {};



	if is_set (private) then

		return table.concat ({code:lower(), 'x', private:lower()}, '-');		-- if private, all other tags ignored

	end

	

	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





--[[--------------------------< G E T _ I E T F _ P A R T S >--------------------------------------------------



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; only one variant subtag supported

	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 (patterni][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 = {

					patterni][2 or 'x' = c2,								-- fill the table of captures with the rest of the captures

					patterni][3 or 'x' = c3,								-- take index names from pattern table and assign sequential captures

					patterni][4 or 'x' = c4,								-- index name may be nil in pattern[i] table so "or 'x'" 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 (override_tablecode or lang_tablecode or synonym_tablecode or lang_dep_tablecode]) 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_tablecode 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_tablecode]}));

		code = synonym_tablecode];												-- 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 script_tablescript 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 suppressed_tablescript then											-- ensure that code-script does not use a suppressed script

		if in_array (code, suppressed_tablescript]) 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 region_tableregion 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 variant_tablevariant 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}), variant_tablevariant]['prefixes']) then

				return code, script, region, nil, nil, table.concat ({'unrecognized variant: ', variant, ' for code-script pair: ', code, '-', script});

			end

		elseif is_set (region) then												-- if region set, there are some prefixes that require lang code and region (en-CA-newfound)

			if not in_array (code, variant_tablevariant]['prefixes']) then		-- first see if lang code is all that's required (en-oxendict though en-GB-oxendict is preferred)

				if not in_array (table.concat ({code, '-', region}), variant_tablevariant]['prefixes']) then		-- now try for lang code and region (en-CA-newfound)

					return code, script, region, nil, nil, table.concat ({'unrecognized variant: ', variant, ' for code-region pair: ', code, '-', region});

				end

			end

		else																	-- cheap way to determine if there are prefixes; fonipa and others don't have prefixes; # operator always returns 0

			if variant_tablevariant]['prefixes'][1 and not in_array (code, variant_tablevariant]['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 override_tabletable.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





--[[--------------------------< M A K E _ E R R O R _ M S G >--------------------------------------------------



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 'Transliteration' == template then

		category = 'Transliteration';

	else

		category = 'Lang and lang-xx'

	end

	

	table.insert (out, table.concat ({'[', args.text or 'undefined', '] '}));	-- for error messages output args.text if available

	table.insert (out, table.concat ({'<span style=\"color:#d33\">Error: {{', template, '}}: '}));

	table.insert (out, msg);

	table.insert (out, table.concat ({' ([[:Category:', category, ' template errors|help]])'}));

	table.insert (out, '</span>');

	

	if (0 == namespace or 10 == namespace) and not args.nocat then				-- categorize in article space (and template space to take care of broken usages)

		table.insert (out, table.concat ({'[[Category:', category, ' template errors]]'}));

	end



	return table.concat (out);

end

	



--[=[-------------------------< M A K E _ W I K I L I N K >----------------------------------------------------



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





--[[--------------------------< D I V _ M A R K U P _ A D D >--------------------------------------------------



adds <i> and </i> tags to list-item text or to implied <p>..</p> 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 text:gsub ('(\n[%*:;#]+)([^\n]+)', '%1<i>%2</i>');			-- 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]+', '<p><i>%1</i></p>');						-- insert p and italic markup tags at each impled p (two or more consecutive '\n\n' sequences)

		else

			text = text:gsub ('[^\n]+', '<p>%1</p>');							-- insert p markup at each impled p

			text = text:gsub ('\n', '');										-- strip newline characters

		end

	end



	return text;

end





--[[--------------------------< T I T L E _ W R A P P E R _ M A K E >------------------------------------------



makes a <span title="<title text>"><content_text></span> or <div title="<title text>"><content_text></div> where

<title text> is in the tool-tip in the wiki's local language and <content_text> is non-local-language text in

html markup.  This because the lang= attibute applies to the content of its enclosing tag.



<tag> holds a string 'div' or 'span' used to choose the correct wrapping tag

]]



local function title_wrapper_make (title_text, content_text, tag)

	local wrapper_t = {};

	

	table.insert (wrapper_t, table.concat ({'<', tag}));						-- open opening wrapper tag

	table.insert (wrapper_t, ' title=\"');										-- begin title attribute

	table.insert (wrapper_t, title_text);										-- add <title_text>

	table.insert (wrapper_t, '\">');											-- end title attribute and close opening wrapper tag

	table.insert (wrapper_t, content_text);										-- add <content_text>

	table.insert (wrapper_t, table.concat ({'</', tag, '>'}));					-- add closing wrapper tag



	return table.concat (wrapper_t);											-- make a big string and done

end





--[[--------------------------< M A K E _ T E X T _ H T M L >--------------------------------------------------



Add the html markup to text according to the type of content that it is: <span> or <i> tags for inline content or

<div> tags for block content



The lang= attribute also applies to the content of the tag where it is placed so this is wrong because 'Spanish

language text' is English:

	<i lang="es" title="Spanish language text">casa</i>

should be:

	<span title="Spanish language text"><i lang="es">casa</i></span>

or for <div>...</div>:

	<div title="Spanish language text"><div lang="es"><spanish-language-text></div></div>



]]



local function make_text_html (code, text, tag, rtl, style, size, language)

	local html_t = {};

	local style_added = '';

	local wrapper_tag = tag;													-- <tag> gets modified so save a copy for use when/if we create a wrapper span or div



	if text:match ('^%*') then

		table.insert (html_t, '&#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 <i> tags

		end

	else																		-- must be div so go

		text = div_markup_add (text, style);									-- handle implied <p>, implied <p> with <i>, and list markup (*;:#) with <i>

	end



	table.insert (html_t, table.concat ({'<', tag}));							-- open the <i>, <span>, or <div> html tag

	code = code:gsub ('%-x%-.*', '');											-- strip private use subtag from code tag because meaningless outside of wikipedia

	table.insert (html_t, table.concat ({' lang="', code, '\"'}));				-- add language attribute



	if (rtl or unicode.is_rtl(text)) and ('ltr' == this_wiki_lang_dir) then		-- text is right-to-left on a left-to-right wiki

		table.insert (html_t, ' dir="rtl"');									-- add direction attribute for right-to-left languages

	elseif not (rtl or unicode.is_rtl(text)) and ('rtl' == this_wiki_lang_dir) then	-- text is left-to-right on a right-to-left wiki

		table.insert (html_t, ' dir="ltr"');									-- add direction attribute for left-to-right languages

	end



	if 'normal' == style then													-- when |italic=no

		table.insert (html_t, ' style=\"font-style: normal;');					-- override external markup, if any

		style_added = '\"';														-- remember that style attribute added and is not yet closed

	end



	if is_set (size) then														-- when |size=<something>

		if is_set (style_added) then

			table.insert (html_t, table.concat ({' font-size: ', size, ';'}));	-- add when style attribute already inserted

		else

			table.insert (html_t, table.concat ({' style=\"font-size: ', size, ';'}));	-- create style attribute

			style_added = '\"';													-- remember that style attribute added and is not yet closed

		end

	end



	table.insert (html_t, table.concat ({style_added, '>'}));					-- close the opening html tag

	table.insert (html_t, text);												-- insert the text



	table.insert (html_t, table.concat ({'</', tag, '>'}));						-- close the 'text' <i>, <span>, or <div> html tag



	if is_set (language) then													-- create a <title_text> string for the title= attribute in a wrapper span or div

		local title_text;

			if 'zxx' == code then												-- special case for this tag 'no linguistic content'

				title_text = table.concat ({language, ' text'});				-- not a language so don't use 'language' in title text

			elseif mw.ustring.find (language, 'languages', 1, true) then

				title_text = table.concat ({language, ' collective text'});		-- for collective languages

			else

				title_text = table.concat ({language, '-language text'});		-- for individual languages

			end



		return title_wrapper_make (title_text, table.concat (html_t), wrapper_tag);

	else

		return table.concat (html_t);

	end

end





--[=[-------------------------< M A K E _ C A T E G O R Y >----------------------------------------------------



For individual language, <language>, returns:

	[[Category:Articles containing <language>-language text]]



for English:

	[[Category:Articles containing explicitly cited English-language text]]

	

for ISO 639-2 collective languages (and for 639-1 bh):

	[[Category:Articles with text in <language> languages]]



]=]



local function make_category (code, language_name, nocat, name_get)

	local cat = {};

	local retval;



	if ((0 ~= namespace) or nocat) and not name_get then						-- only categorize in article space

		return '';																-- return empty string for concatenation

	end



	if mw.ustring.find (language_name, 'languages', 1, true) then

		return table.concat ({'[[Category:Articles with text in ', language_name, ']]'});

	end

		

	table.insert (cat, '[[Category:Articles containing ');



	if this_wiki_lang_tag == code then

		table.insert (cat, 'explicitly cited ' .. language_name);				-- unique category name for the local language

	else

		table.insert (cat, language_name);

	end

	

	table.insert (cat, '-language text]]');



	return table.concat (cat);

end





--[[--------------------------< M A K E _ T R A N S L I T >----------------------------------------------------



return translit <i lang=xx-Latn>...</i> where xx is the language code; else return empty string



The value |script= is not used in {{transliteration}} for this purpose; instead it uses |code.  Because language scripts

are listed in the {{transliteration}} 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 {{transliteration}}, style only applies when a language code is provided

]]



local function make_translit (code, language_name, translit, std, tscript, style)

	local title;

	local out_t = {};

	local title_t = lang_data.translit_title_table;								-- table of transliteration standards and the language codes and scripts that apply to those standards

	local title_text = '';														-- tool tip text for title= attribute

	

	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

		title_text = language_name;												-- write a generic tool tip

		if not mw.ustring.find (language_name, 'languages', 1, true) then		-- collective language names (plural 'languages' is part of the name)

			title_text = title_text .. '-language';								-- skip this text (individual and macro languages only)

		end

		title_text = title_text .. ' 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_tstd then													-- and if standard is legitimate

			if title_tstd][tscript then										-- and if script for that standard is legitimate

				if script_tabletscript then

					title_text = title_text .. table.concat ({title_tstd][tscript:lower()], ' (', script_tabletscript], ' script) transliteration'});	-- add the appropriate text to the tool tip

				else

					title_text = title_text .. title_tstd]['default'];			-- use the default if script not in std table; TODO: maint cat? error message because script not found for this standard?

				end

			else

				title_text = title_text .. title_tstd]['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_tstd then return ''; end									-- invalid standard, setup for error message

		

		if title_tstd][code then												-- if language code is in the table (transl may not provide a language code)

			title_text = title_text .. table.concat ({title_tstd][code:lower()], ' (', language_name, ' language) transliteration'});	-- add the appropriate text to the tool tip

		else																	-- code doesn't match

			title_text = title_text .. title_tstd]['default'];					-- so use the standard's default

		end



	else																		-- here if translit-script set but translit-std not set

		if title_t'no_std'][tscript then

			title_text = title_text .. title_t'no_std'][tscript];				-- use translit-script if set

		elseif title_t'no_std'][code then

			title_text = title_text .. title_t'no_std'][code];					-- use language code

		else

			if is_set (tscript) then

				title_text = title_text .. table.concat ({language_name, '-script transliteration'});	-- write a script tool tip

			elseif is_set (code) then

				if not mw.ustring.find (language_name, 'languages', 1, true) then	-- collective language names (plural 'languages' is part of the name)

					title_text = title_text .. '-language';						-- skip this text (individual and macro languages only)

				end

				title_text = title_text .. ' transliteration';					-- finish the tool tip

			else

				title_text = title_text .. ' transliteration';					-- generic tool tip (can we ever get here?)

			end

		end

	end



	local close_tag;

	if is_set (code) then														-- when a language code is provided (always with {{lang-xx}} templates, not always with {{transliteration}})

		code = code:match ('^(%a%a%a?)');										-- strip all subtags leaving only the language subtag



		if not style then														-- nil for the default italic style

			table.insert (out_t, "<i lang=\"");									-- so use <i> tag

			close_tag = '</i>';													-- tag to be used when closing

		else

			table.insert (out_t, table.concat ({'<span style=\"font-style: ', style, '\" lang=\"'}));	-- non-standard style, construct a span tag for it

			close_tag = '</span>';												-- tag to be used when closing

		end

		table.insert (out_t, code);

		table.insert (out_t, "-Latn\">");										-- transliterations are always Latin script

	else

		table.insert (out_t, "<span>");											-- when no language code: no lang= attribute, not italic ({{transliteration}} only)

		close_tag = '</span>';

	end



	table.insert (out_t, translit);												-- add the translit text

	table.insert (out_t, close_tag);											-- and add the appropriate </i> or </span>



	if '' == title_text then													-- when there is no need for a tool-tip

		return table.concat (out_t);											-- make a string and done

	else

		return title_wrapper_make (title_text, table.concat (out_t), 'span');	-- wrap with a tool-tip span and don

	end

end





--[[--------------------------< V A L I D A T E _ T E X T >----------------------------------------------------



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 ("%f[\'\'\'\'\'%f[^\']") or args.text:find ("\'\'\'\'\'\']+") 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 ("%f[\'\'\'%f[^\']") or args.text:find ("%f[\'\'\'\'\'\'%f[^\']") then	-- italic but not bold, or bold italic

			return make_error_msg ('text has italic markup', args, template);

		end

	end

end





--[[--------------------------< R E N D E R _ M A I N T >------------------------------------------------------



render mainenance messages and categories



]]



local function render_maint(nocat)

	local maint = {};

	

	if 0 < #maint_msgs then														-- when there are maintenance messages

		table.insert (maint, table.concat ({'<span class="lang-comment" style="font-style: normal; display: none; color: #33aa33; margin-left: 0.3em;">'}));	-- opening <span> tag

		for _, msg in ipairs (maint_msgs) do

			table.insert (maint, table.concat ({msg, ' '}));					-- add message strings

		end

		table.insert (maint, '</span>');										-- close the span

	end

	

	if (0 < #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 ({'[[Category:', cat, ']]'}));	-- format and add the categories

		end

	end

	

	return table.concat (maint);

end





--[[--------------------------< P R O T O _ P R E F I X >------------------------------------------------------



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





--[[--------------------------< H A S _ P O E M _ T A G >------------------------------------------------------



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





--[[--------------------------< H T M L _ T A G _ S E L E C T >------------------------------------------------



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 <p>..</p> 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 <poem>...</poem> stripmarker, return text unmodified and choose <div>..</div> tags because 

the stripmarker is replaced with text wrapped in <div>..</div> tags.



If the text contains any actual <div>...</div> tags, then it's again returned unmodified and <div>...</div>

tags are used to wrap it, to prevent div/span inversion.



]]



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 text:find ('<div') then												-- reductive; if the text contains a div tag, we must use div tags

		tag = 'div';

	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





--[[--------------------------< V A L I D A T E _ P R O T O >--------------------------------------------------



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





--[[--------------------------< L A N G U A G E _ N A M E _ G E T >--------------------------------------------



common function to return language name from the data set according to IETF tag



returns language name if found in data tables; nil else



]]



local function language_name_get (ietf, code, cat)

	ietf = ietf:lower();														-- ietf:lower() because format_ietf_tag() returns mixed case

	

	local name;																	-- remains nil if not found

	

	if override_tableietf then												-- look for whole IETF tag in override table

		name = override_tableietf];

	elseif override_tablecode then											-- not there so try basic language tag

		name = override_tablecode];

	elseif lang_tablecode then												-- shift to iana active tag/name table

		name = lang_tablecode];

	elseif lang_dep_tablecode then											-- try the iana deprecated tag/name table

		name = lang_dep_tablecode];

	end



	if lang_dep_tablecode and cat then										-- because deprecated code may have been overridden to en.wiki preferred name

		table.insert (maint_cats, table.concat ({'Lang and lang-xx using deprecated ISO 639 codes|', code}));

		table.insert (maint_msgs, table.concat ({'code: ', code, ' is deprecated'}));

	end



	return name;																-- name from data tables or nil

end





--[[--------------------------< _ L A N G >--------------------------------------------------------------------



entry point for {{lang}}



there should be no reason to set parameters in the {{lang}} {{#invoke:}}

	<includeonly>{{#invoke:lang|lang}}</includeonly>



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 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, 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';



	maint_cats = {};															-- initialize because when this module required into another module, these only declared once so only initialzed once

	maint_msgs = {};

	

	validate_cat_args (args);													-- determine if categorization should be suppressed



	if args1 and args.code then

		return make_error_msg ('conflicting: {{{1}}} and |code=', args, template);

	else

		args.code = args1 or args.code;										-- prefer args.code

	end



	if args2 and args.text then

		return make_error_msg ('conflicting: {{{2}}} and |text=', args, template);

	else

		args.text = args2 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



	args.rtl = args.rtl == 'yes';												-- convert to boolean: 'yes' -> true, other values -> 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 |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_tag ~= 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, subtags.private);	-- format to recommended subtag styles

	language_name = language_name_get (args.code, code, true);					-- get language name; try ietf tag first, then code w/o variant then code w/ variant



	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





--[[--------------------------< L A N G >----------------------------------------------------------------------



entry point for {{lang}}



there should be no reason to set parameters in the {{lang}} {{#invoke:}}

	<includeonly>{{#invoke:lang|lang}}</includeonly>



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





--[[--------------------------< T R A N S L A T I O N _ M A K E >----------------------------------------------



stand-alone function to create literal translation of main text



Also used by {{lang-x2}}



]]



local function translation_make (args_t)

	local translation_t = {', '};												-- initialize output



	if 'none' ~= args_t.label then												-- if we want a label

		table.insert (translation_t, '<small>');								-- open the <small> html tag

		if 'no' == args_t.link then

			table.insert (translation_t, '<abbr title="literal translation">lit.</abbr>');	-- unlinked form

		else

			table.insert (translation_t, make_wikilink ('Literal translation', 'lit.'));	-- linked form

		end

		table.insert (translation_t, "&thinsp;</small>");						-- close the <small> html tag

	end

	table.insert (translation_t, table.concat ({'&#39;', args_t.translation, '&#39;'}));	-- use html entities to avoid wiki markup confusion

	return table.concat (translation_t);										-- make a big string and done

end





--[[--------------------------< L A N G _ X X >----------------------------------------------------------------



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:

	<includeonly>{{#invoke:lang|lang_xx_inherit|code=xx}}</includeonly>

For italic style:

	<includeonly>{{#invoke:lang|lang_xx_italic|code=xx}}</includeonly>



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';



	maint_cats = {};															-- initialize because when this module required into another module, these only declared once so only initialzed once

	maint_msgs = {};

	

	if args1 and args.text then

		return make_error_msg ('conflicting: {{{1}}} and |text=', args, template);

	else

		args.text = args1 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 args2 and args.translit then

		return make_error_msg ('conflicting: {{{2}}} and |translit=', args, template);

	else

		args.translit = args2 or args.translit								-- prefer args.translit

	end

	

	if args3 and (args.translation or args.lit) then

		return make_error_msg ('conflicting: {{{3}}} and |lit= or |translation=', args, template);

	elseif args.translation and args.lit then

		return make_error_msg ('conflicting: |lit= and |translation=', args, template);

	else

		args.translation = args3 or args.translation or args.lit;				-- prefer args.translation

	end



	if args.links and args.link then

		return make_error_msg ('conflicting: |links= and |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' -> true, other values -> 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:<initial_style_state>

			end

		else

			args.italic = initial_style_state;									-- here when |italic= and |script= not set; set for font-style:<initial_style_state>

		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 |proto=: ', args.proto}), args, template);

	end



	args.code = format_ietf_tag (code, subtags.script, subtags.region, subtags.variant, subtags.private);	-- format to recommended subtag styles

	language_name = language_name_get (args.code, code, true);					-- get language name; try ietf tag first, then code w/o variant then code w/ variant



	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 mw.ustring.find (language_name, 'languages', 1, true) then

				table.insert (out, make_wikilink (language_name));				-- collective language name uses simple wikilink

			elseif lang_data.article_namecode then

				table.insert (out, make_wikilink (lang_data.article_namecode], language_name));	-- language name with wikilink from override data

			else

				table.insert (out, make_wikilink (language_name .. ' language', 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, ('none' == args.label) and language_name or nil))



	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, '<small>');

			if script_tableargs'translit-script']] then						-- when |translit-script= is set, try to use the script's name

				translit_script_name = script_tableargs'translit-script']];

			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, '&nbsp;</small>');								-- 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, translation_make (args));

	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





--[[--------------------------< L A N G _ X X _ A R G S _ G E T >----------------------------------------------



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





--[[--------------------------< L A N G _ X X _ I T A L I C >--------------------------------------------------



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





--[[--------------------------< _ L A N G _ X X _ I T A L I C >------------------------------------------------



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





--[[--------------------------< L A N G _ X X _ I N H E R I T >------------------------------------------------



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





--[[--------------------------< _ L A N G _ X X _ I N H E R I T >----------------------------------------------



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





--[[--------------------------< _ I S _ I E T F _ T A G >------------------------------------------------------



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.



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, variant, 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





--[[--------------------------< I S _ I E T F _ T A G >--------------------------------------------------------



Module entry point from an {{#invoke:}}



]]



local function is_ietf_tag (frame)

	return _is_ietf_tag (getArgs (frame)[1]);									-- args[1] is the ietf language tag to be tested; also get parent frame

end





--[[--------------------------< I S _ I E T F _ T A G _ F R A M E >--------------------------------------------



Module entry point from an {{#invoke:}}; same as is_ietf_tag() except does not get parameters from the parent

(template) frame.  This function not useful when called by {{lang|fn=is_ietf_tag_frame|<tag>}} because <tag>

is in the parent frame.



]]



local function is_ietf_tag_frame (frame)

	return _is_ietf_tag (getArgs (frame, {frameOnly = true,})[1]);				-- args[1] is the ietf language tag to be tested; do not get parent frame

end





--[[--------------------------< _ N A M E _ F R O M _ T A G >--------------------------------------------------



Returns language name associated with IETF language tag if valid; error message 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 = args1];													-- save a copy of the input IETF subtag

	local link = 'yes' == args'link'];											-- make a boolean

	local label = args.label;

	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 ({'<span style=\"color:#d33\">Error: ', template, msg, '</span>'});

	end



	raw_code = format_ietf_tag (code, subtags.script, subtags.region, subtags.variant, subtags.private);	-- format to recommended subtag styles; private omitted because private

	language_name = language_name_get (raw_code, code);							-- get language name; try ietf tag first, then code w/o variant then code w/ variant



	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 mw.ustring.find (language_name, 'languages', 1, true) then

			language_name = make_wikilink (language_name, label);				-- collective language name uses simple wikilink

		elseif lang_data.article_namecode then

			language_name = make_wikilink (lang_data.article_namecode], label or language_name);	-- language name with wikilink from override data

		else

			language_name = make_wikilink (language_name .. ' language', label or language_name);	-- language name with wikilink

		end

	end



	return language_name;

end





--[[--------------------------< N A M E _ F R O M _ T A G >----------------------------------------------------



Module entry point from an {{#invoke:}}



]]



local function name_from_tag (frame)											-- entry point from an {{#invoke:Lang|name_from_tag|<ietf tag>|link=<yes>|template=<template name>}}

	return _name_from_tag (getArgs(frame))										-- pass-on the args table, nothing else; getArgs() so we also get parent frame

end





--[[--------------------------< _ T A G _ F R O M _ N A M E >--------------------------------------------------



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 args1 and '' ~= args1 then

		local data = mw.loadData ('Module:Lang/tag from name');					-- get the reversed data tables TODO: change when going live

		local lang = args1]:lower();											-- allow any-case for the language name (speeling must till be correct)

		local tag = data.rev_override_tablelang or data.rev_lang_tablelang or data.rev_lang_dep_tablelang];	-- get the code; look first in the override then in the standard



		if tag then

			return tag, true;													-- language name found so return tag and done; second return used by is_lang_name()

		else

			msg = 'language: ' .. args1 .. ' 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 ({'<span style=\"color:#d33\">Error: ', template, msg, '</span>'});

end





--[[--------------------------< T A G _ F R O M _ N A M E >----------------------------------------------------



Module entry point from an {{#invoke:}}



]]



local function tag_from_name (frame)											-- entry point from an {{#invoke:Lang|tag_from_name|<language name>|link=<yes>|template=<template name>}}

	local result, _ = _tag_from_name (getArgs(frame))							-- pass-on the args table, nothing else; getArgs() so we also get parent frame; supress second return used by is_lang_name()

	return result;		

end





--[[--------------------------< I S _ L A N G _ N A M E >------------------------------------------------------



Module entry point from an {{#invoke:}}



]]



local function is_lang_name (frame)

	local _, result = _tag_from_name (getArgs(frame))							-- pass-on the args table, nothing else; getArgs() so we also get parent frame; supress second return used by tag_from_name()

	return result and true or nil;		

end





--[[--------------------------< _ T R A N S L >----------------------------------------------------------------



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;																-- transliterated text to display

	local script;																-- IANA script

	local msg;																	-- for when called functions return an error message



	maint_cats = {};															-- initialize because when this module required into another module, these only declared once so only initialzed once

	maint_msgs = {};

	

	if is_set (args3]) then													-- [3] set when {{transliteration|code|standard|text}}

		args.text = args3];													-- get the transliterated text

		args.translit_std = args2 and args2]:lower();						-- get the standard; lower case for table indexing



		if not title_tableargs.translit_std then

			return make_error_msg (table.concat ({'unrecognized transliteration standard: ', args.translit_std}), args, 'Transliteration');

		end

	else

		if is_set (args2]) then												-- [2] set when {{transliteration|code|text}}

			args.text = args2];												-- get the transliterated text

		else

			if args1 and (args1]:match ('^%a%a%a?%a?$') or					-- args[2] missing; is args[1] a language or script tag or is it the transliterated text?

				args1]:match ('^%a%a%a?%-x%-')) then							-- or is args[1] a private-use tag

					return make_error_msg ('no text', args, 'Transliteration');	-- args[1] is a code so we're missing text

			else

				args.text = args1];											-- 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, 'Transliteration');

			end

		end

	end



	if is_set (args1]) then													-- IANA language code used for html lang= attribute; or ISO 15924 script code

		if args1]:match ('^%a%a%a?%a?$') or args1]:match ('^%a%a%a?%-x%-') then	-- args[1] has correct form?

			args.code = args1]:lower();										-- use the language/script code; only (2, 3, or 4 alpha characters) or private-use; lower case because table indexes are lower case

		else

			return make_error_msg (table.concat ({'unrecognized language / script code: ', args1]}), args, 'Transliteration');	-- invalid language / script code

		end

	else

		return make_error_msg ('missing language / script code', args, 'Transliteration');	-- missing language / script code so quit

	end



	args.italic, msg = validate_italic (args);

	if msg then

		return make_error_msg (msg, args, 'Transliteration');

	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 override_tableargs.code then											-- is code a language code defined in the override table?

		language_name = override_tableargs.code];

		args.code = args.code:match ('^%a%a%a?');								-- if private use, strip all but language subtag

	elseif lang_tableargs.code then											-- is code a language code defined in the standard language code tables?

		language_name = lang_tableargs.code];

	elseif lang_dep_tableargs.code then										-- is code a language code defined in the deprecated language code tables?

		language_name = lang_dep_tableargs.code];

	elseif script_tableargs.code then											-- if here, code is not a language code; is it a script code?

		language_name = script_tableargs.code];

		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, 'Transliteration');	-- 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





--[[--------------------------< T R A N S L >------------------------------------------------------------------



Module entry point from an {{#invoke:}}



]]



local function transl (frame)

	return _transl (getArgs(frame));

end





--[[--------------------------< C A T E G O R Y _ F R O M _ T A G >--------------------------------------------



Returns category name associated with IETF language tag if valid; error message else



All code combinations supported by {{lang}} and the {{lang-xx}} templates are supported by this function.



Module entry point from another module



]]



local function _category_from_tag (args_t)

	local subtags = {};															-- IETF subtags script, region, variant, and private

	local raw_code = args_t1];													-- save a copy of the input IETF subtag

	local link = 'yes' == args_t.link;											-- make a boolean

	local label = args_t.label;

	local code;																	-- the language code

	local msg;																	-- gets an error message if IETF language tag is malformed or invalid

	local category_name = '';

	

	code, subtags.script, subtags.region, subtags.variant, subtags.private, msg = get_ietf_parts (raw_code);

	if msg then

		local template = (args_t.template and table.concat ({'{{', args_t.template, '}}: '})) or '';	-- make template name (if provided by the template)

		return table.concat ({'<span style=\"color:#d33\">Error: ', template, msg, '</span>'});

	end



	raw_code = format_ietf_tag (code, subtags.script, subtags.region, subtags.variant, subtags.private);	-- format to recommended subtag styles; private omitted because private

	category_name = language_name_get (raw_code, code);							-- get language name; try ietf tag first, then code w/o variant then code w/ variant

	category_name = make_category (code, category_name, nil, true):gsub ('[%[%]]', '');



	if link then

		return table.concat ({'[[:', category_name, ']]'});

	else

		return category_name;

	end

end





--[[--------------------------< C A T E G O R Y _ F R O M _ T A G >--------------------------------------------



Module entry point from an {{#invoke:}}



]]



local function category_from_tag (frame)										-- entry point from an {{#invoke:Lang|category_from_tag|<ietf tag>|template=<template name>}}

	return _category_from_tag (getArgs (frame));								-- pass-on the args table, nothing else; getArgs() so we also get parent frame

end





--[[--------------------------< E X P O R T E D   F U N C T I O N S >------------------------------------------

]]



return {

	category_from_tag = category_from_tag,

	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,

	is_ietf_tag_frame = is_ietf_tag_frame,

	is_lang_name = is_lang_name,

	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 {{transliteration}}

	

	_category_from_tag = _category_from_tag,									-- entry points when this module is require()d into other modules

	_lang = _lang,

	_lang_xx_inherit = _lang_xx_inherit,

	_lang_xx_italic = _lang_xx_italic,

	_is_ietf_tag = _is_ietf_tag,

	get_ietf_parts = get_ietf_parts,

	_tag_from_name = _tag_from_name, 

	_name_from_tag = _name_from_tag,

	_transl = _transl,

	_translation_make = translation_make,

	};