local z = {  error_categories = {}; -- for categorizing citations that contain errors  error_ids = {};  message_tail = {};  maintenance_cats = {}; -- for categorizing citations that aren't erroneous per se, but could use a little work  properties_cats = {}; -- for categorizing citations based on certain properties, language of source for instance };   --[[--------------------------< F O R W A R D D E C L A R A T I O N S >-------------------------------------- ]]  local cfg; -- table of tables imported from selected Module:Citation/CS1/Configuration   --[[--------------------------< 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 _ 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   --[[--------------------------< S U B S T I T U T E >----------------------------------------------------------  Populates numbered arguments in a message string using an argument table.  ]]  local function substitute( msg, args )  return args and mw.message.newRawMessage( msg, args ):plain() or msg; end   --[[--------------------------< E R R O R _ C O M M E N T >----------------------------------------------------  Wraps error messages with css markup according to the state of hidden.  ]]  local function error_comment( content, hidden )  return substitute( hidden and cfg.presentation['hidden-error'] or cfg.presentation['visible-error'], content ); end   --[=[-------------------------< M A K E _ W I K I L I N K >----------------------------------------------------  Makes a wikilink; when bot 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   --[[--------------------------< S E T _ E R R O R >--------------------------------------------------------------  Sets an error condition and returns the appropriate error message. The actual placement of the error message in the output is the responsibility of the calling function.  ]]  local function set_error( error_id, arguments, raw, prefix, suffix )  local error_state = cfg.error_conditions[ error_id ];   prefix = prefix or "";  suffix = suffix or "";   if error_state == nil then  error( cfg.messages['undefined_error'] ); -- because missing error handler in Module:Citation/CS1/Configuration  elseif is_set( error_state.category ) then  table.insert( z.error_categories, error_state.category );  end   local message = substitute( error_state.message, arguments );   message = table.concat (  {  message,  ' (',  make_wikilink (  table.concat (  {  cfg.messages['help page link'],  '#',  error_state.anchor  }),  cfg.messages['help page label']),  ')'  });   z.error_ids[ error_id ] = true;  if in_array( error_id, { 'bare_url_missing_title', 'trans_missing_title' } )  and z.error_ids['citation_missing_title'] then  return '', false;  end   message = table.concat({ prefix, message, suffix });   if raw == true then  return message, error_state.hidden;  end   return error_comment( message, error_state.hidden ); end   --[[-------------------------< I S _ A L I A S _ U S E D >-----------------------------------------------------  This function is used by select_one() to determine if one of a list of alias parameters is in the argument list provided by the template.  Input:  args – pointer to the arguments table from calling template  alias – one of the list of possible aliases in the aliases lists from Module:Citation/CS1/Configuration  index – for enumerated parameters, identifies which one  enumerated – true/false flag used choose how enumerated aliases are examined  value – value associated with an alias that has previously been selected; nil if not yet selected  selected – the alias that has previously been selected; nil if not yet selected  error_list – list of aliases that are duplicates of the alias already selected  Returns:  value – value associated with alias we selected or that was previously selected or nil if an alias not yet selected  selected – the alias we selected or the alias that was previously selected or nil if an alias not yet selected  ]]  local function is_alias_used (args, alias, index, enumerated, value, selected, error_list)  if enumerated then -- is this a test for an enumerated parameters?  alias = alias:gsub ('#', index); -- replace '#' with the value in index  else  alias = alias:gsub ('#', ''); -- remove '#' if it exists  end   if is_set(args[alias]) then -- alias is in the template's argument list  if value ~= nil and selected ~= alias then -- if we have already selected one of the aliases  local skip;  for _, v in ipairs(error_list) do -- spin through the error list to see if we've added this alias  if v == alias then  skip = true;  break; -- has been added so stop looking   end  end  if not skip then -- has not been added so  table.insert( error_list, alias ); -- add error alias to the error list  end  else  value = args[alias]; -- not yet selected an alias, so select this one  selected = alias;  end  end  return value, selected; -- return newly selected alias, or previously selected alias end   --[[--------------------------< A D D _ M A I N T _ C A T >------------------------------------------------------  Adds a category to z.maintenance_cats using names from the configuration file with additional text if any. To prevent duplication, the added_maint_cats table lists the categories by key that have been added to z.maintenance_cats.  ]]  local added_maint_cats = {} -- list of maintenance categories that have been added to z.maintenance_cats local function add_maint_cat (key, arguments)  if not added_maint_cats [key] then  added_maint_cats [key] = true; -- note that we've added this category  table.insert( z.maintenance_cats, substitute (cfg.maint_cats [key], arguments)); -- make name then add to table  end end   --[[--------------------------< S A F E _ F O R _ I T A L I C S >----------------------------------------------  Protects a string that will be wrapped in wiki italic markup '' ... ''  Note: We cannot use <i> for italics, as the expected behavior for italics specified by ''...'' in the title is that they will be inverted (i.e. unitalicized) in the resulting references. In addition, <i> and '' tend to interact poorly under Mediawiki's HTML tidy.  ]]  local function safe_for_italics( str )  if not is_set(str) then  return str;  else  if str:sub(1,1) == "'" then str = "<span></span>" .. str; end  if str:sub(-1,-1) == "'" then str = str .. "<span></span>"; end   -- Remove newlines as they break italics.  return str:gsub( '\n', ' ' );  end end   --[[--------------------------< W R A P _ S T Y L E >----------------------------------------------------------  Applies styling to various parameters. Supplied string is wrapped using a message_list configuration taking one argument; protects italic styled parameters. Additional text taken from citation_config.presentation - the reason this function is similar to but separate from wrap_msg().  ]]  local function wrap_style (key, str)  if not is_set( str ) then  return "";  elseif in_array( key, { 'italic-title', 'trans-italic-title' } ) then  str = safe_for_italics( str );  end   return substitute( cfg.presentation[key], {str} ); end   --[[--------------------------< S E L E C T _ O N E >----------------------------------------------------------  Chooses one matching parameter from a list of parameters to consider. The list of parameters to consider is just names. For parameters that may be enumerated, the position of the numerator in the parameter name is identified by the '#' so |author-last1= and |author1-last= are represented as 'author-last#' and 'author#-last'.  Because enumerated parameter |<param>1= is an alias of |<param>= we must test for both possibilities.   Generates an error if more than one match is present.  ]]  local function select_one( args, aliases_list, error_condition, index )  local value = nil; -- the value assigned to the selected parameter  local selected = ''; -- the name of the parameter we have chosen  local error_list = {};   if index ~= nil then index = tostring(index); end   for _, alias in ipairs( aliases_list ) do -- for each alias in the aliases list  if alias:match ('#') then -- if this alias can be enumerated  if '1' == index then -- when index is 1 test for enumerated and non-enumerated aliases  value, selected = is_alias_used (args, alias, index, false, value, selected, error_list); -- first test for non-enumerated alias  end  value, selected = is_alias_used (args, alias, index, true, value, selected, error_list); -- test for enumerated alias  else  value, selected = is_alias_used (args, alias, index, false, value, selected, error_list); --test for non-enumerated alias  end  end   if #error_list > 0 and 'none' ~= error_condition then -- for cases where this code is used outside of extract_names()  local error_str = "";  for _, k in ipairs( error_list ) do  if error_str ~= "" then error_str = error_str .. cfg.messages['parameter-separator'] end  error_str = error_str .. wrap_style ('parameter', k);  end  if #error_list > 1 then  error_str = error_str .. cfg.messages['parameter-final-separator'];  else  error_str = error_str .. cfg.messages['parameter-pair-separator'];  end  error_str = error_str .. wrap_style ('parameter', selected);  table.insert( z.message_tail, { set_error( error_condition, {error_str}, true ) } );  end   return value, selected; end   --[=[-------------------------< R E M O V E _ W I K I _ L I N K >----------------------------------------------  Gets the display text from a wikilink like [[A|B]] or [[B]] gives B  The str:gsub() returns either A|B froma [[A|B]] or B from [[B]] or B from B (no wikilink markup).  In l(), l:gsub() removes the link and pipe (if they exist); the second :gsub() trims white space from the label if str was wrapped in wikilink markup. Presumably, this is because without wikimarkup in str, there is no match in the initial gsub, the replacement function l() doesn't get called.  ]=]  local function remove_wiki_link (str)  return (str:gsub( "%[%[([^%[%]]*)%]%]", function(l)  return l:gsub( "^[^|]*|(.*)$", "%1" ):gsub("^%s*(.-)%s*$", "%1");  end)); end   --[=[-------------------------< I S _ W I K I L I N K >--------------------------------------------------------  Determines if str is a wikilink, extracts, and returns the the wikilink type, link text, and display text parts. If str is a complex wikilink ([[L|D]]):  returns wl_type 2 and D and L from [[L|D]]; if str is a simple wikilink ([[D]])  returns wl_type 1 and D from [[D]] and L as empty string; if not a wikilink:  returns wl_type 0, str as D, and L as empty string.  trims leading and trailing white space and pipes from L and D ([[L|]] and [[|D]] are accepted by MediaWiki and treated like [[D]]; while [[|D|]] is not accepted by MediaWiki, here, we accept it and return D without the pipes).  ]=]  local function is_wikilink (str)  local D, L  local wl_type = 2; -- assume that str is a complex wikilink [[L|D]]   if not str:match ('^%[%[[^%]]+%]%]$') then -- is str some sort of a wikilink (must have some sort of content)  return 0, str, ''; -- not a wililink; return wl_type as 0, str as D, and empty string as L  end   L, D = str:match ('^%[%[([^|]+)|([^%]]+)%]%]$'); -- get L and D from [[L|D]]    if not is_set (D) then -- if no separate display  D = str:match ('^%[%[([^%]]*)|*%]%]$'); -- get D from [[D]] or [[D|]]  wl_type = 1;  end   D = mw.text.trim (D, '%s|'); -- trim white space and pipe characters  -- L = L and mw.text.trim (L, '%s|');  return wl_type, D, L or ''; end   --[[--------------------------< S T R I P _ A P O S T R O P H E _ M A R K U P >--------------------------------  Strip wiki italic and bold markup from argument so that it doesn't contaminate COinS metadata. This function strips common patterns of apostrophe markup. We presume that editors who have taken the time to markup a title have, as a result, provided valid markup. When they don't, some single apostrophes are left behind.  Returns the argument without wiki markup and a number; the number is more-or-less meaningless except as a flag to indicate that markup was replaced; do not rely on it as an indicator of how many of any kind of markup was removed; returns the argument and nil when no markup removed  ]]  local function strip_apostrophe_markup (argument)  if not is_set (argument) then  return argument, nil; -- no argument, nothing to do  end   if nil == argument:find ( "''", 1, true ) then -- Is there at least one double apostrophe? If not, exit.  return argument, nil;  end   local flag;  while true do  if argument:find ( "'''''", 1, true ) then -- bold italic (5)  argument, flag=argument:gsub("%'%'%'%'%'", ""); -- remove all instances of it  elseif argument:find ( "''''", 1, true ) then -- italic start and end without content (4)  argument, flag=argument:gsub("%'%'%'%'", "");  elseif argument:find ( "'''", 1, true ) then -- bold (3)  argument, flag=argument:gsub("%'%'%'", "");  elseif argument:find ( "''", 1, true ) then -- italic (2)  argument, flag=argument:gsub("%'%'", "");  else  break;  end  end   return argument, flag; -- done end   --[[--------------------------< S E T _ S E L E C T E D _ M O D U L E S >--------------------------------------  Sets local cfg table to same (live or sandbox) as that used by the other modules.  ]]  local function set_selected_modules (cfg_table_ptr)  cfg = cfg_table_ptr;  end   --[[--------------------------< E X P O R T S >---------------------------------------------------------------- ]]  return {  is_set = is_set, -- exported functions  in_array = in_array,  substitute = substitute,  error_comment = error_comment,  set_error = set_error,  select_one = select_one,  add_maint_cat = add_maint_cat,  wrap_style = wrap_style,  safe_for_italics = safe_for_italics,  remove_wiki_link = remove_wiki_link,  is_wikilink = is_wikilink,  make_wikilink = make_wikilink,  set_selected_modules = set_selected_modules,  strip_apostrophe_markup = strip_apostrophe_markup,  z = z, -- exported table  }