--[[--------------------------< F O R W A R D D E C L A R A T I O N S >-------------------------------------- ]]  local is_set, in_array; -- imported functions from selected Module:Citation/CS1/Utilities local cfg; -- table of tables imported from selected Module:Citation/CS1/Configuration   --[[--------------------------< F I L E - S C O P E D E C L A R A T I O N S >--------------------------------  File-scope variables are declared here  ]]  local lang_object = mw.getContentLanguage(); -- used by is_valid_accessdate(), is_valid_year(), date_name_xlate(); TODO: move to ~/Configuration? local year_limit; -- used by is_valid_year()   --[=[-------------------------< I S _ V A L I D _ A C C E S S D A T E >----------------------------------------  returns true if:  Wikipedia start date <= accessdate < today + 2 days  Wikipedia start date is 2001-01-15T00:00:00 UTC which is 979516800 seconds after 1970-01-01T00:00:00 UTC (the start of Unix time) accessdate is the date provided in |accessdate= at time 00:00:00 UTC today is the current date at time 00:00:00 UTC plus 48 hours  if today is 2015-01-01T00:00:00 then  adding 24 hours gives 2015-01-02T00:00:00 – one second more than today  adding 24 hours gives 2015-01-03T00:00:00 – one second more than tomorrow  This function does not work if it is fed month names for languages other than English. Wikimedia #time: parser apparently doesn't understand non-Engish date month names. This function will always return false when the date contains a non-English month name because good1 is false after the call to lang.formatDate(). To get around that call this function with YYYY-MM-DD format dates.  ]=]  local function is_valid_accessdate (accessdate)  local good1, good2;  local access_ts, tomorrow_ts; -- to hold unix time stamps representing the dates   good1, access_ts = pcall (lang_object.formatDate, lang_object, 'U', accessdate ); -- convert accessdate value to unix timesatmp   good2, tomorrow_ts = pcall (lang_object.formatDate, lang_object, 'U', 'today + 2 days' ); -- today midnight + 2 days is one second more than all day tomorrow   if good1 and good2 then -- lang.formatDate() returns a timestamp in the local script which which tonumber() may not understand  access_ts = tonumber (access_ts) or lang_object:parseFormattedNumber (access_ts); -- convert to numbers for the comparison;  tomorrow_ts = tonumber (tomorrow_ts) or lang_object:parseFormattedNumber (tomorrow_ts);  else  return false; -- one or both failed to convert to unix time stamp  end   if 979516800 <= access_ts and access_ts < tomorrow_ts then -- Wikipedia start date <= accessdate < tomorrow's date  return true;  else  return false; -- accessdate out of range  end end   --[[--------------------------< I S _ V A L I D _ E M B A R G O _ D A T E >------------------------------------  returns true and date value if that value has proper dmy, mdy, ymd format.  returns false and 9999 (embargoed forever) when date value is not proper format; assumes that when |embargo= is set, the editor intended to embargo a pmc but |embargo= does not hold a single date.  ]]  local function is_valid_embargo_date (v)  if v:match ('^%d%d%d%d%-%d%d%-%d%d$') or -- ymd  v:match ('^%d%d?%s+%a+%s+%d%d%d%d$') or -- dmy  v:match ('^%a+%s+%d%d?%s*,%s*%d%d%d%d$') then -- mdy  return true, v;  end  return false, '9999'; -- if here not good date so return false and set embargo date to long time in future end   --[[--------------------------< G E T _ M O N T H _ N U M B E R >----------------------------------------------  returns a number according to the month in a date: 1 for January, etc. Capitalization and spelling must be correct. If not a valid month, returns 0  ]]  local function get_month_number (month)  return cfg.date_names['local'].long[month] or cfg.date_names['local'].short[month] or -- look for local names first  cfg.date_names['en'].long[month] or cfg.date_names['en'].short[month] or -- failing that, look for English names  0; -- not a recognized month name end   --[[--------------------------< G E T _ S E A S O N _ N U M B E R >--------------------------------------------  returns a number according to the sequence of seasons in a year: 21 for Spring, etc. Capitalization and spelling must be correct. If not a valid season, returns 0.  21-24 = Spring, Summer, Autumn, Winter, independent of “Hemisphere”  returns 0 when <param> is not |date=  Season numbering is defined by Extended Date/Time Format (EDTF) Specification (https://www.loc.gov/standards/datetime/) which became part of ISO 8601 in 2019. See '§Sub-year groupings'. The standard defines various divisions using numbers 21-41. cs1|2 only supports generic seasons. EDTF does support the distinction between north and south hemispere seasons but cs1|2 has no way to make that distinction.  These additional divisions not currently supported:  25-28 = Spring - Northern Hemisphere, Summer- Northern Hemisphere, Autumn - Northern Hemisphere, Winter - Northern Hemisphere  29-32 = Spring – Southern Hemisphere, Summer– Southern Hemisphere, Autumn – Southern Hemisphere, Winter - Southern Hemisphere  33-36 = Quarter 1, Quarter 2, Quarter 3, Quarter 4 (3 months each)  37-39 = Quadrimester 1, Quadrimester 2, Quadrimester 3 (4 months each)  40-41 = Semestral 1, Semestral-2 (6 months each)  ]]  local function get_season_number (season, param)  if 'date' ~= param then  return 0; -- season dates only supported by |date=  end  return cfg.date_names['local'].season[season] or -- look for local names first  cfg.date_names['en'].season[season] or -- failing that, look for English names  0; -- not a recognized season name end   --[[--------------------------< G E T _ Q U A R T E R _ N U M B E R >------------------------------------------  returns a number according to the sequence of quarters in a year: 33 for first quarter, etc. Capitalization and spelling must be correct. If not a valid quarter, returns 0.  33-36 = Quarter 1, Quarter 2, Quarter 3, Quarter 4 (3 months each)  returns 0 when <param> is not |date=  Quarter numbering is defined by Extended Date/Time Format (EDTF) Specification (https://www.loc.gov/standards/datetime/) which became part of ISO 8601 in 2019. See '§Sub-year groupings'. The standard defines various divisions using numbers 21-41. cs1|2 only supports generic seasons and quarters.  These additional divisions not currently supported:  37-39 = Quadrimester 1, Quadrimester 2, Quadrimester 3 (4 months each)  40-41 = Semestral 1, Semestral-2 (6 months each)  ]]  local function get_quarter_number (quarter, param)  if 'date' ~= param then  return 0; -- quarter dates only supported by |date=  end  quarter = mw.ustring.gsub (quarter, ' +', ' '); -- special case replace multiple space chars with a single space char  return cfg.date_names['local'].quarter[quarter] or -- look for local names first  cfg.date_names['en'].quarter[quarter] or -- failing that, look for English names  0; -- not a recognized quarter name end   --[[--------------------------< G E T _ P R O P E R _ N A M E _ N U M B E R >----------------------------------  returns a non-zero number if date contains a recognized proper-name. Capitalization and spelling must be correct.  returns 0 when <param> is not |date=  ]]  local function get_proper_name_number (name, param)  if 'date' ~= param then  return 0; -- proper-name dates only supported by |date=  end  return cfg.date_names['local'].named[name] or -- look for local names dates first  cfg.date_names['en'].named[name] or -- failing that, look for English names  0; -- not a recognized named date end   --[[--------------------------< G E T _ E L E M E N T _ N U M B E R <------------------------------------------  returns true if month or season or quarter or proper name is valid (properly spelled, capitalized, abbreviated)  ]]  local function get_element_number (element, param)  local num;   local funcs = {get_month_number, get_season_number, get_quarter_number, get_proper_name_number}; -- list of functions to execute in order   for _, func in ipairs (funcs) do -- spin through the function list  num = func (element, param); -- call the function and get the returned number  if 0 ~= num then -- non-zero when valid month season quarter   return num; -- return that number  end  end  return nil; -- not valid end   --[[--------------------------< I S _ V A L I D _ Y E A R >----------------------------------------------------  Function gets current year from the server and compares it to year from a citation parameter. Years more than one year in the future are not acceptable.  ]]  local function is_valid_year (year)  if not is_set(year_limit) then  year_limit = tonumber(os.date("%Y"))+1; -- global variable so we only have to fetch it once  end   year = tonumber (year) or lang_object:parseFormattedNumber (year); -- convert to numbers for the comparison;  return year and (year <= year_limit) or false; end   --[[--------------------------< I S _ V A L I D _ D A T E >----------------------------------------------------  Returns true if day is less than or equal to the number of days in month and year is no farther into the future than next year; else returns false.  Assumes Julian calendar prior to year 1582 and Gregorian calendar thereafter. Accounts for Julian calendar leap years before 1582 and Gregorian leap years after 1582. Where the two calendars overlap (1582 to approximately 1923) dates are assumed to be Gregorian.  ]]  local function is_valid_date (year, month, day) local days_in_month = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; local month_length;  if not is_valid_year(year) then -- no farther into the future than next year  return false;  end   month = tonumber(month); -- required for YYYY-MM-DD dates   if (2==month) then -- if February  month_length = 28; -- then 28 days unless  if 1582 > tonumber(year) then -- Julian calendar  if 0==(year%4) then -- is a leap year?  month_length = 29; -- if leap year then 29 days in February  end  else -- Gregorian calendar  if (0==(year%4) and (0~=(year%100) or 0==(year%400))) then -- is a leap year?  month_length = 29; -- if leap year then 29 days in February  end  end  else  month_length=days_in_month[month];  end   if tonumber (day) > month_length then  return false;  end  return true; end   --[[--------------------------< I S _ V A L I D _ M O N T H _ R A N G E _ S T Y L E >--------------------------  Months in a range are expected to have the same style: Jan–Mar or October–December but not February–Mar or Jul–August.  There is a special test for May because it can be either short or long form.  Returns true when style for both months is the same  ]]  local function is_valid_month_range_style (month1, month2) local len1 = month1:len(); local len2 = month2:len();  if len1 == len2 then  return true; -- both months are short form so return true  elseif 'May' == month1 or 'May'== month2 then  return true; -- both months are long form so return true  elseif 3 == len1 or 3 == len2 then  return false; -- months are mixed form so return false  else  return true; -- both months are long form so return true  end end   --[[--------------------------< I S _ V A L I D _ M O N T H _ S E A S O N _ R A N G E >------------------------  Check a pair of months or seasons to see if both are valid members of a month or season pair.  Month pairs are expected to be left to right, earliest to latest in time.  All season ranges are accepted as valid because there are publishers out there who have published a Summer–Spring YYYY issue so ... ok  ]]  local function is_valid_month_season_range(range_start, range_end, param)  local range_start_number = get_month_number (range_start);  local range_end_number;   if 0 == range_start_number then -- is this a month range?  range_start_number = get_season_number (range_start, param); -- not a month; is it a season? get start season number  range_end_number = get_season_number (range_end, param); -- get end season number   if (0 ~= range_start_number) and (0 ~= range_end_number) then  return true; -- any season pairing is accepted  end  return false; -- range_start and/or range_end is not a season  end  -- here when range_start is a month  range_end_number = get_month_number (range_end); -- get end month number  if range_start_number < range_end_number then -- range_start is a month; does range_start precede range_end?  if is_valid_month_range_style (range_start, range_end) then -- do months have the same style?  return true; -- proper order and same style  end  end  return false; -- range_start month number is greater than or equal to range end number; or range end isn't a month end   --[[--------------------------< M A K E _ C O I N S _ D A T E >------------------------------------------------  This function receives a table of date parts for one or two dates and an empty table reference declared in Module:Citation/CS1. The function is called only for |date= parameters and only if the |date=<value> is  determined to be a valid date format. The question of what to do with invalid date formats is not answered here.  The date parts in the input table are converted to an ISO 8601 conforming date string:  single whole dates: yyyy-mm-dd  month and year dates: yyyy-mm  year dates: yyyy  ranges: yyyy-mm-dd/yyyy-mm-dd  yyyy-mm/yyyy-mm  yyyy/yyyy  Dates in the Julian calendar are reduced to year or year/year so that we don't have to do calendar conversion from Julian to Proleptic Gregorian.  The input table has:  year, year2 – always present; if before 1582, ignore months and days if present  month, month2 – 0 if not provided, 1-12 for months, 21-24 for seasons; 99 Christmas  day, day2 – 0 if not provided, 1-31 for days   the output table receives:  rftdate: an IS8601 formatted date  rftchron: a free-form version of the date, usually without year which is in rftdate (season ranges and proper-name dates)  rftssn: one of four season keywords: winter, spring, summer, fall (lowercase)  rftquarter: one of four values: 1, 2, 3, 4  ]]  local function make_COinS_date (input, tCOinS_date)  local date; -- one date or first date in a range  local date2 = ''; -- end of range date -- start temporary Julian / Gregorian calendar uncertainty detection  local year = tonumber(input.year); -- this temporary code to determine the extent of sources dated to the Julian/Gregorian  local month = tonumber(input.month); -- interstice 1 October 1582 – 1 January 1926  local day = tonumber (input.day);  if (0 ~= day) and -- day must have a value for this to be a whole date  (((1582 == year) and (10 <= month) and (12 >= month)) or -- any whole 1582 date from 1 october to 31 December or  ((1926 == year) and (1 == month) and (1 == input.day)) or -- 1 January 1926 or  ((1582 < year) and (1925 >= year))) then -- any date 1 January 1583 – 31 December 1925  tCOinS_date.inter_cal_cat = true; -- set category flag true  end -- end temporary Julian / Gergorian calendar uncertainty detection   if 1582 > tonumber(input.year) or 20 < tonumber(input.month) then -- Julian calendar or season so &rft.date gets year only  date = input.year;  if 0 ~= input.year2 and input.year ~= input.year2 then -- if a range, only the second year portion when not the same as range start year  date = string.format ('%.4d/%.4d', tonumber(input.year), tonumber(input.year2)) -- assemble the date range  end  if 20 < tonumber(input.month) then -- if season or proper-name date  local season = {[24]='winter', [21]='spring', [22]='summer', [23]='fall', [33]='1', [34]='2', [35]='3', [36]='4', [98]='Easter', [99]='Christmas'}; -- seasons lowercase, no autumn; proper-names use title case  if 0 == input.month2 then -- single season date  if 40 <tonumber(input.month) then  tCOinS_date.rftchron = season[input.month]; -- proper-name dates  elseif 30 <tonumber(input.month) then  tCOinS_date.rftquarter = season[input.month]; -- quarters  else  tCOinS_date.rftssn = season[input.month]; -- seasons  end  else -- season range with a second season specified  if input.year ~= input.year2 then -- season year – season year range or season year–year  tCOinS_date.rftssn = season[input.month]; -- start of range season; keep this?  if 0~= input.month2 then  tCOinS_date.rftchron = string.format ('%s %s – %s %s', season[input.month], input.year, season[input.month2], input.year2);  end  else -- season–season year range  tCOinS_date.rftssn = season[input.month]; -- start of range season; keep this?  tCOinS_date.rftchron = season[input.month] .. '–' .. season[input.month2]; -- season–season year range  end  end  end  tCOinS_date.rftdate = date;  return; -- done  end   if 0 ~= input.day then  date = string.format ('%s-%.2d-%.2d', input.year, tonumber(input.month), tonumber(input.day)); -- whole date  elseif 0 ~= input.month then  date = string.format ('%s-%.2d', input.year, tonumber(input.month)); -- year and month  else  date = string.format ('%s', input.year); -- just year  end   if 0 ~= input.year2 then  if 0 ~= input.day2 then  date2 = string.format ('/%s-%.2d-%.2d', input.year2, tonumber(input.month2), tonumber(input.day2)); -- whole date  elseif 0 ~= input.month2 then  date2 = string.format ('/%s-%.2d', input.year2, tonumber(input.month2)); -- year and month  else  date2 = string.format ('/%s', input.year2); -- just year  end  end   tCOinS_date.rftdate = date .. date2; -- date2 has the '/' separator  return; end   --[[--------------------------< P A T T E R N S >--------------------------------------------------------------  this is the list of patterns for date formats that this module recognizes. Approximately the first half of these patterns represent formats that might be reformatted into another format. Those that might be reformatted have 'indicator' letters that identify the content of the matching capture: 'd' (day), 'm' (month), 'a' (anchor year), 'y' (year); second day, month, year have a '2' suffix.  These patterns are used for both date validation and for reformatting. This table should not be moved to ~/Configuration because changes to this table require changes to check_date() and to reformatter() and reformat_date()  ]]  local patterns = {  -- year-initial numerical year-month-day  ['ymd'] = {'^(%d%d%d%d)%-(%d%d)%-(%d%d)$', 'y', 'm', 'd'},  -- month-initial: month day, year  ['Mdy'] = {'^(%D-) +([1-9]%d?), +((%d%d%d%d?)%a?)$', 'm', 'd', 'a', 'y'},  -- month-initial day range: month day–day, year; days are separated by endash  ['Md-dy'] = {'^(%D-) +([1-9]%d?)[%-–]([1-9]%d?), +((%d%d%d%d)%a?)$', 'm', 'd', 'd2', 'a', 'y'},  -- day-initial: day month year  ['dMy'] = {'^([1-9]%d?) +(%D-) +((%d%d%d%d?)%a?)$', 'd', 'm', 'a', 'y'},  -- year-initial: year month day; day: 1 or 2 two digits, leading zero allowed; not supported at en.wiki -- ['yMd'] = {'^((%d%d%d%d?)%a?) +(%D-) +(%d%d?)$', 'a', 'y', 'm', 'd'},  -- day-range-initial: day–day month year; days are separated by endash  ['d-dMy'] = {'^([1-9]%d?)[%-–]([1-9]%d?) +(%D-) +((%d%d%d%d)%a?)$', 'd', 'd2', 'm', 'a', 'y'},  -- day initial month-day-range: day month - day month year; uses spaced endash  ['dM-dMy'] = {'^([1-9]%d?) +(%D-) +[%-–] +([1-9]%d?) +(%D-) +((%d%d%d%d)%a?)$', 'd', 'm', 'd2', 'm2', 'a', 'y'},  -- month initial month-day-range: month day – month day, year; uses spaced endash  ['Md-Mdy'] = {'^(%D-) +([1-9]%d?) +[%-–] +(%D-) +([1-9]%d?), +((%d%d%d%d)%a?)$','m', 'd', 'm2', 'd2', 'a', 'y'},  -- day initial month-day-year-range: day month year - day month year; uses spaced endash  ['dMy-dMy'] = {'^([1-9]%d?) +(%D-) +(%d%d%d%d) +[%-–] +([1-9]%d?) +(%D-) +((%d%d%d%d)%a?)$', 'd', 'm', 'y', 'd2', 'm2', 'a', 'y2'},  -- month initial month-day-year-range: month day, year – month day, year; uses spaced endash  ['Mdy-Mdy'] = {'^(%D-) +([1-9]%d?), +(%d%d%d%d) +[%-–] +(%D-) +([1-9]%d?), +((%d%d%d%d)%a?)$', 'm', 'd', 'y', 'm2', 'd2', 'a', 'y2'},   -- these date formats cannot be converted, per se, but month name can be rendered short or long  -- month/season year - month/season year; separated by spaced endash  ['My-My'] = {'^(%D-) +(%d%d%d%d) +[%-–] +(%D-) +((%d%d%d%d)%a?)$', 'm', 'y', 'm2', 'a', 'y2'},  -- month/season range year; months separated by endash  ['M-My'] = {'^(%D-)[%-–](%D-) +((%d%d%d%d)%a?)$', 'm', 'm2', 'a', 'y'},  -- month/season year or proper-name year; quarter year when First Quarter YYYY etc  ['My'] = {'^([^%d–]-) +((%d%d%d%d)%a?)$', 'm', 'a', 'y'}, -- this way because endash is a member of %D; %D- will match January–March 2019 when it shouldn't   -- these date formats cannot be converted -- ['Q,y'] = {'^(Q%a* +[1-4]), +((%d%d%d%d)%a?)$'}, -- Quarter n, yyyy   ['Sy4-y2'] = {'^(%D-) +((%d%d)%d%d)[%-–]((%d%d)%a?)$'}, -- special case Winter/Summer year-year (YYYY-YY); year separated with unspaced endash  ['Sy-y'] = {'^(%D-) +(%d%d%d%d)[%-–]((%d%d%d%d)%a?)$'}, -- special case Winter/Summer year-year; year separated with unspaced endash  ['y-y'] = {'^(%d%d%d%d?)[%-–]((%d%d%d%d?)%a?)$'}, -- year range: YYY-YYY or YYY-YYYY or YYYY–YYYY; separated by unspaced endash; 100-9999  ['y4-y2'] = {'^((%d%d)%d%d)[%-–]((%d%d)%a?)$'}, -- year range: YYYY–YY; separated by unspaced endash  ['y'] = {'^((%d%d%d%d?)%a?)$'}, -- year; here accept either YYY or YYYY  }   --[[--------------------------< C H E C K _ D A T E >----------------------------------------------------------  Check date format to see that it is one of the formats approved by WP:DATESNO or WP:DATERANGE. Exception: only allowed range separator is endash. Additionally, check the date to see that it is a real date: no 31 in 30-day months; no 29 February when not a leap year. Months, both long-form and three character abbreviations, and seasons must be spelled correctly. Future years beyond next year are not allowed.  If the date fails the format tests, this function returns false and does not return values for anchor_year and COinS_date. When this happens, the date parameter is used in the COinS metadata and the CITEREF identifier gets its year from the year parameter if present otherwise CITEREF does not get a date value.  Inputs:  date_string - date string from date-holding parameters (date, year, accessdate, embargo, archivedate, etc.)  Returns:  false if date string is not a real date; else  true, anchor_year, COinS_date  anchor_year can be used in CITEREF anchors  COinS_date is ISO 8601 format date; see make_COInS_date()  ]]  local function check_date (date_string, param, tCOinS_date)  local year; -- assume that year2, months, and days are not used;  local year2=0; -- second year in a year range  local month=0;  local month2=0; -- second month in a month range  local day=0;  local day2=0; -- second day in a day range  local anchor_year;  local coins_date;   if date_string:match (patterns['ymd'][1]) then -- year-initial numerical year month day format  year, month, day=date_string:match (patterns['ymd'][1]);  if 12 < tonumber(month) or 1 > tonumber(month) or 1582 > tonumber(year) or 0 == tonumber(day) then return false; end -- month or day number not valid or not Gregorian calendar  anchor_year = year;  -- elseif mw.ustring.match(date_string, patterns['Q,y'][1]) then -- quarter n, year; here because much the same as Mdy -- month, anchor_year, year=mw.ustring.match(date_string, patterns['Q,y'][1]); -- if not is_valid_year(year) then return false; end -- month = get_quarter_number (month, param); -- get quarter number or nil -- if not month then return false; end -- not valid whatever it is   elseif mw.ustring.match(date_string, patterns['Mdy'][1]) then -- month-initial: month day, year  month, day, anchor_year, year=mw.ustring.match(date_string, patterns['Mdy'][1]);  month = get_month_number (month);  if 0 == month then return false; end -- return false if month text isn't one of the twelve months   elseif mw.ustring.match(date_string, patterns['Md-dy'][1]) then -- month-initial day range: month day–day, year; days are separated by endash  month, day, day2, anchor_year, year=mw.ustring.match(date_string, patterns['Md-dy'][1]);  if tonumber(day) >= tonumber(day2) then return false; end -- date range order is left to right: earlier to later; dates may not be the same;  month = get_month_number (month);  if 0 == month then return false; end -- return false if month text isn't one of the twelve months  month2=month; -- for metadata  year2=year;   elseif mw.ustring.match(date_string, patterns['dMy'][1]) then -- day-initial: day month year  day, month, anchor_year, year=mw.ustring.match(date_string, patterns['dMy'][1]);  month = get_month_number (month);  if 0 == month then return false; end -- return false if month text isn't one of the twelve months  --[[ NOT supported at en.wiki  elseif mw.ustring.match(date_string, patterns['yMd'][1]) then -- year-initial: year month day; day: 1 or 2 two digits, leading zero allowed  anchor_year, year, month, day=mw.ustring.match(date_string, patterns['yMd'][1]);  month = get_month_number (month);  if 0 == month then return false; end -- return false if month text isn't one of the twelve months -- end NOT supported at en.wiki ]]   elseif mw.ustring.match(date_string, patterns['d-dMy'][1]) then -- day-range-initial: day–day month year; days are separated by endash  day, day2, month, anchor_year, year=mw.ustring.match(date_string, patterns['d-dMy'][1]);  if tonumber(day) >= tonumber(day2) then return false; end -- date range order is left to right: earlier to later; dates may not be the same;  month = get_month_number (month);  if 0 == month then return false; end -- return false if month text isn't one of the twelve months  month2=month; -- for metadata  year2=year;   elseif mw.ustring.match(date_string, patterns['dM-dMy'][1]) then -- day initial month-day-range: day month - day month year; uses spaced endash  day, month, day2, month2, anchor_year, year=mw.ustring.match(date_string, patterns['dM-dMy'][1]);  if (not is_valid_month_season_range(month, month2)) or not is_valid_year(year) then return false; end -- date range order is left to right: earlier to later;  month = get_month_number (month); -- for metadata  month2 = get_month_number (month2);  year2=year;   elseif mw.ustring.match(date_string, patterns['Md-Mdy'][1]) then -- month initial month-day-range: month day – month day, year; uses spaced endash  month, day, month2, day2, anchor_year, year=mw.ustring.match(date_string, patterns['Md-Mdy'][1]);  if (not is_valid_month_season_range(month, month2, param)) or not is_valid_year(year) then return false; end  month = get_month_number (month); -- for metadata  month2 = get_month_number (month2);  year2=year;   elseif mw.ustring.match(date_string, patterns['dMy-dMy'][1]) then -- day initial month-day-year-range: day month year - day month year; uses spaced endash  day, month, year, day2, month2, anchor_year, year2=mw.ustring.match(date_string, patterns['dMy-dMy'][1]);  if tonumber(year2) <= tonumber(year) then return false; end -- must be sequential years, left to right, earlier to later  if not is_valid_year(year2) or not is_valid_month_range_style(month, month2) then return false; end -- year2 no more than one year in the future; months same style  month = get_month_number (month); -- for metadata  month2 = get_month_number (month2);   elseif mw.ustring.match(date_string, patterns['Mdy-Mdy'][1]) then -- month initial month-day-year-range: month day, year – month day, year; uses spaced endash  month, day, year, month2, day2, anchor_year, year2=mw.ustring.match(date_string, patterns['Mdy-Mdy'][1]);  if tonumber(year2) <= tonumber(year) then return false; end -- must be sequential years, left to right, earlier to later  if not is_valid_year(year2) or not is_valid_month_range_style(month, month2) then return false; end -- year2 no more than one year in the future; months same style  month = get_month_number (month); -- for metadata  month2 = get_month_number (month2);   elseif mw.ustring.match(date_string, patterns['Sy4-y2'][1]) then -- special case Winter/Summer year-year (YYYY-YY); year separated with unspaced endash  local century;  month, year, century, anchor_year, year2=mw.ustring.match(date_string, patterns['Sy4-y2'][1]);  if 'Winter' ~= month and 'Summer' ~= month then return false end; -- 'month' can only be Winter or Summer  anchor_year=year..'–'..anchor_year; -- assemble anchor_year from both years  year2 = century..year2; -- add the century to year2 for comparisons  if 1 ~= tonumber(year2) - tonumber(year) then return false; end -- must be sequential years, left to right, earlier to later  if not is_valid_year(year2) then return false; end -- no year farther in the future than next year  month = get_season_number (month, param);   elseif mw.ustring.match(date_string, patterns['Sy-y'][1]) then -- special case Winter/Summer year-year; year separated with unspaced endash  month, year, anchor_year, year2=mw.ustring.match(date_string, patterns['Sy-y'][1]);  if 'Winter' ~= month and 'Summer' ~= month then return false end; -- 'month' can only be Winter or Summer  anchor_year=year..'–'..anchor_year; -- assemble anchor_year from both years  if 1 ~= tonumber(year2) - tonumber(year) then return false; end -- must be sequential years, left to right, earlier to later  if not is_valid_year(year2) then return false; end -- no year farther in the future than next year  month = get_season_number (month, param); -- for metadata   elseif mw.ustring.match(date_string, patterns['My-My'][1]) then -- month/season year - month/season year; separated by spaced endash  month, year, month2, anchor_year, year2=mw.ustring.match(date_string, patterns['My-My'][1]);  anchor_year=year..'–'..anchor_year; -- assemble anchor_year from both years  if tonumber(year) >= tonumber(year2) then return false; end -- left to right, earlier to later, not the same  if not is_valid_year(year2) then return false; end -- no year farther in the future than next year  if 0 ~= get_month_number(month) and 0 ~= get_month_number(month2) and is_valid_month_range_style(month, month2) then -- both must be month year, same month style  month = get_month_number(month);  month2 = get_month_number(month2);  elseif 0 ~= get_season_number(month, param) and 0 ~= get_season_number(month2, param) then -- both must be season year, not mixed  month = get_season_number(month, param);  month2 = get_season_number(month2, param);  else  return false;  end   elseif mw.ustring.match(date_string, patterns['M-My'][1]) then -- month/season range year; months separated by endash   month, month2, anchor_year, year=mw.ustring.match(date_string, patterns['M-My'][1]);  if (not is_valid_month_season_range(month, month2, param)) or (not is_valid_year(year)) then return false; end  if 0 ~= get_month_number(month) then -- determined to be a valid range so just check this one to know if month or season  month = get_month_number(month);  month2 = get_month_number(month2);  else  month = get_season_number(month, param);  month2 = get_season_number(month2, param);  end  year2=year;   elseif mw.ustring.match(date_string, patterns['My'][1]) then -- month/season/quarter/proper-name year  month, anchor_year, year=mw.ustring.match(date_string, patterns['My'][1]);  if not is_valid_year(year) then return false; end  month = get_element_number (month, param); -- get month season quarter proper-name number or nil  if not month then return false; end -- not valid whatever it is   elseif mw.ustring.match(date_string, patterns['y-y'][1]) then -- Year range: YYY-YYY or YYY-YYYY or YYYY–YYYY; separated by unspaced endash; 100-9999  year, anchor_year, year2=mw.ustring.match(date_string, patterns['y-y'][1]);  anchor_year=year..'–'..anchor_year; -- assemble anchor year from both years  if tonumber(year) >= tonumber(year2) then return false; end -- left to right, earlier to later, not the same  if not is_valid_year(year2) then return false; end -- no year farther in the future than next year   elseif mw.ustring.match(date_string, patterns['y4-y2'][1]) then -- Year range: YYYY–YY; separated by unspaced endash  local century;  year, century, anchor_year, year2=mw.ustring.match(date_string, patterns['y4-y2'][1]);  anchor_year=year..'–'..anchor_year; -- assemble anchor year from both years  if 13 > tonumber(year2) then return false; end -- don't allow 2003-05 which might be May 2003  year2 = century..year2; -- add the century to year2 for comparisons  if tonumber(year) >= tonumber(year2) then return false; end -- left to right, earlier to later, not the same  if not is_valid_year(year2) then return false; end -- no year farther in the future than next year   elseif mw.ustring.match (date_string, patterns['y'][1]) then -- year; here accept either YYY or YYYY  anchor_year, year=mw.ustring.match (date_string, patterns['y'][1]);  if false == is_valid_year(year) then  return false;  end   else  return false; -- date format not one of the MOS:DATE approved formats  end   if 'access-date' == param then -- test accessdate here because we have numerical date parts  if 0 ~= year and 0 ~= month and 0 ~= day and -- all parts of a single date required  0 == year2 and 0 == month2 and 0 == day2 then -- none of these; accessdate must not be a range  if not is_valid_accessdate (year..'-'..month..'-'..day) then  return false; -- return false when accessdate out of bounds  end  else  return false; -- return false when accessdate is a range of two dates  end  end   local result=true; -- check whole dates for validity; assume true because not all dates will go through this test  if 0 ~= year and 0 ~= month and 0 ~= day and 0 == year2 and 0 == month2 and 0 == day2 then -- YMD (simple whole date)  result=is_valid_date(year,month,day);   elseif 0 ~= year and 0 ~= month and 0 ~= day and 0 == year2 and 0 == month2 and 0 ~= day2 then -- YMD-d (day range)  result=is_valid_date(year,month,day);  result=result and is_valid_date(year,month,day2);   elseif 0 ~= year and 0 ~= month and 0 ~= day and 0 == year2 and 0 ~= month2 and 0 ~= day2 then -- YMD-md (day month range)  result=is_valid_date(year,month,day);  result=result and is_valid_date(year,month2,day2);   elseif 0 ~= year and 0 ~= month and 0 ~= day and 0 ~= year2 and 0 ~= month2 and 0 ~= day2 then -- YMD-ymd (day month year range)  result=is_valid_date(year,month,day);  result=result and is_valid_date(year2,month2,day2);  end   if false == result then return false; end   if nil ~= tCOinS_date then -- this table only passed into this function when testing |date= parameter values  make_COinS_date ({year=year, month=month, day=day, year2=year2, month2=month2, day2=day2}, tCOinS_date); -- make an ISO 8601 date string for COinS  end   return true, anchor_year; -- format is good and date string represents a real date end   --[[--------------------------< D A T E S >--------------------------------------------------------------------  Cycle the date-holding parameters in passed table date_parameters_list through check_date() to check compliance with MOS:DATE. For all valid dates, check_date() returns true. The |date= parameter test is unique, it is the only date holding parameter from which values for anchor_year (used in CITEREF identifiers) and COinS_date (used in the COinS metadata) are derived. The |date= parameter is the only date-holding parameter that is allowed to contain the no-date keywords "n.d." or "nd" (without quotes).  Unlike most error messages created in this module, only one error message is created by this function. Because all of the date holding parameters are processed serially, a single error message is created as the dates are tested.  ]]  local function dates(date_parameters_list, tCOinS_date)  local anchor_year; -- will return as nil if the date being tested is not |date=  local COinS_date; -- will return as nil if the date being tested is not |date=  local embargo_date; -- if embargo date is a good dmy, mdy, ymd date then holds original value else reset to 9999  local error_message = "";  local good_date = false;   for k, v in pairs(date_parameters_list) do -- for each date-holding parameter in the list  if is_set(v.val) then -- if the parameter has a value  v.val = mw.ustring.gsub (v.val, '%d', cfg.date_names.local_digits); -- translate 'local' digits to Western 0-9  if v.val:match("^c%. [1-9]%d%d%d?%a?$") then -- special case for c. year or with or without CITEREF disambiguator - only |date= and |year=  local year = v.val:match("c%. ([1-9]%d%d%d?)%a?"); -- get the year portion so it can be tested  if 'date'==k then  anchor_year, COinS_date = v.val:match("((c%. [1-9]%d%d%d?)%a?)"); -- anchor year and COinS_date only from |date= parameter  good_date = is_valid_year(year);  elseif 'year'==k then  good_date = is_valid_year(year);  end  elseif 'date'==k then -- if the parameter is |date=  if v.val:match("^n%.d%.%a?$") then -- if |date=n.d. with or without a CITEREF disambiguator  good_date, anchor_year, COinS_date = true, v.val:match("((n%.d%.)%a?)"); --"n.d."; no error when date parameter is set to no date  elseif v.val:match("^nd%a?$") then -- if |date=nd with or without a CITEREF disambiguator  good_date, anchor_year, COinS_date = true, v.val:match("((nd)%a?)"); --"nd"; no error when date parameter is set to no date  else  good_date, anchor_year, COinS_date = check_date (v.val, k, tCOinS_date); -- go test the date  end  elseif 'year'==k then -- if the parameter is |year= it should hold only a year value  if v.val:match("^[1-9]%d%d%d?%a?$") then -- if |year= 3 or 4 digits only with or without a CITEREF disambiguator  good_date, anchor_year, COinS_date = true, v.val:match("((%d+)%a?)");  end  elseif 'embargo'==k then -- if the parameter is |embargo=  good_date = check_date (v.val, k); -- go test the date  if true == good_date then -- if the date is a valid date  good_date, embargo_date = is_valid_embargo_date (v.val); -- is |embargo= date a single dmy, mdy, or ymd formatted date? yes:returns embargo; no: returns 9999  end  else -- any other date-holding parameter  good_date = check_date (v.val, k); -- go test the date  end  if false==good_date then -- assemble one error message so we don't add the tracking category multiple times  if is_set(error_message) then -- once we've added the first portion of the error message ...  error_message=error_message .. ", "; -- ... add a comma space separator  end  error_message=error_message .. "&#124;" .. v.name .. "="; -- add the failed parameter  end  end  end  return anchor_year, embargo_date, error_message; -- and done end   --[[--------------------------< Y E A R _ D A T E _ C H E C K >------------------------------------------------  Compare the value provided in |year= with the year value(s) provided in |date=. This function returns a numeric value:  0 - year value does not match the year value in date  1 - (default) year value matches the year value in date or one of the year values when date contains two years  2 - year value matches the year value in date when date is in the form YYYY-MM-DD and year is disambiguated (|year=YYYYx)  ]]  local function year_date_check (year_string, date_string)  local year;  local date1;  local date2;  local result = 1; -- result of the test; assume that the test passes   year = year_string:match ('(%d%d%d%d?)');   if date_string:match ('%d%d%d%d%-%d%d%-%d%d') and year_string:match ('%d%d%d%d%a') then --special case where both date and year are required YYYY-MM-DD and YYYYx  date1 = date_string:match ('(%d%d%d%d)');  year = year_string:match ('(%d%d%d%d)');  if year ~= date1 then  result = 0; -- years don't match  else  result = 2; -- years match; but because disambiguated, don't add to maint cat  end   elseif date_string:match ("%d%d%d%d?.-%d%d%d%d?") then -- any of the standard range formats of date with two three- or four-digit years  date1, date2 = date_string:match ("(%d%d%d%d?).-(%d%d%d%d?)");  if year ~= date1 and year ~= date2 then  result = 0;  end   elseif mw.ustring.match(date_string, "%d%d%d%d[%-–]%d%d") then -- YYYY-YY date ranges  local century;  date1, century, date2 = mw.ustring.match(date_string, "((%d%d)%d%d)[%-–]+(%d%d)");  date2 = century..date2; -- convert YY to YYYY  if year ~= date1 and year ~= date2 then  result = 0;  end   elseif date_string:match ("%d%d%d%d?") then -- any of the standard formats of date with one year  date1 = date_string:match ("(%d%d%d%d?)");  if year ~= date1 then  result = 0;  end  else  result = 0; -- no recognizable year in date  end  return result; end   --[[--------------------------< R E F O R M A T T E R >--------------------------------------------------------  reformat 'date' into new format specified by format_param if pattern_idx (the current format of 'date') can be reformatted. Does the grunt work for reformat_dates().  The table re_formats maps patern_idx (current format) and format_param (desired format) to a table that holds:  format string used by string.format()  identifier letters ('d', 'm', 'y', 'd2', 'm2', 'y2') that serve as indexes into a table t{} that holds captures  from mw.ustring.match() for the various date parts specified by patterns[pattern_idx][1]  Items in patterns{} have the general form:  ['ymd'] = {'^(%d%d%d%d)%-(%d%d)%-(%d%d)$', 'y', 'm', 'd'}, where:  ['ymd'] is pattern_idx  patterns['ymd'][1] is the match pattern with captures for mw.ustring.match()  patterns['ymd'][2] is an indicator letter identifying the content of the first capture  patterns['ymd'][3] ... the second capture etc  when a pattern matches a date, the captures are loaded into table t{} in capture order using the idemtifier characters as indexes into t{} For the above, a ymd date is in t{} as:  t.y = first capture (year), t.m = second capture (month), t.d = third capture (day)  To reformat, this function is called with the pattern_idx that matches the current format of the date and with format_param set to the desired format. This function loads table t{} as described and then calls string.format() with the format string specified by re_format[pattern_idx][format_param][1] using values taken from t{} according to the capture identifier letters specified by patterns[pattern_idx][format_param][n] where n is 2..  ]]  local re_formats = {  ['ymd'] = { -- date format is ymd; reformat to:  ['mdy'] = {'%s %s, %s', 'm', 'd', 'y'}, -- |df=mdy  ['dmy'] = {'%s %s %s', 'd', 'm', 'y'}, -- |df=dmy -- ['yMd'] = {'%s %s %s', 'y', 'm', 'd'}, -- |df=yMd; not supported at en.wiki  },  ['Mdy'] = { -- date format is Mdy; reformat to:  ['mdy'] = {'%s %s, %s', 'm', 'd', 'y'}, -- for long/short reformatting  ['dmy'] = {'%s %s %s', 'd', 'm', 'y'}, -- |df=dmy  ['ymd'] = {'%s-%s-%s', 'y', 'm', 'd'}, -- |df=ymd -- ['yMd'] = {'%s %s %s', 'y', 'm', 'd'}, -- |df=yMd; not supported at en.wiki  },  ['dMy'] = { -- date format is dMy; reformat to:  ['dmy'] = {'%s %s %s', 'd', 'm', 'y'}, -- for long/short reformatting  ['mdy'] = {'%s %s, %s', 'm', 'd', 'y'}, -- |df=mdy  ['ymd'] = {'%s-%s-%s', 'y', 'm', 'd'}, -- |df=ymd -- ['yMd'] = {'%s %s %s', 'y', 'm', 'd'}, -- |df=yMd; not supported at en.wiki  },  ['Md-dy'] = { -- date format is Md-dy; reformat to:  ['mdy'] = {'%s %s–%s, %s', 'm', 'd', 'd2', 'y'}, -- for long/short reformatting  ['dmy'] = {'%s–%s %s %s', 'd', 'd2', 'm', 'y'}, -- |df=dmy -> d-dMy   },  ['d-dMy'] = { -- date format is d-d>y; reformat to:  ['dmy'] = {'%s–%s %s %s', 'd', 'd2', 'm', 'y'}, -- for long/short reformatting  ['mdy'] = {'%s %s–%s, %s', 'm', 'd', 'd2', 'y'}, -- |df=mdy -> Md-dy   },  ['dM-dMy'] = { -- date format is dM-dMy; reformat to:  ['dmy'] = {'%s %s – %s %s %s', 'd', 'm', 'd2', 'm2', 'y'}, -- for long/short reformatting  ['mdy'] = {'%s %s – %s %s, %s', 'm', 'd', 'm2', 'd2', 'y'}, -- |df=mdy -> Md-Mdy   },  ['Md-Mdy'] = { -- date format is Md-Mdy; reformat to:  ['mdy'] = {'%s %s – %s %s, %s', 'm', 'd', 'm2', 'd2', 'y'}, -- for long/short reformatting  ['dmy'] = {'%s %s – %s %s %s', 'd', 'm', 'd2', 'm2', 'y'}, -- |df=dmy -> dM-dMy   },  ['dMy-dMy'] = { -- date format is dMy-dMy; reformat to:  ['dmy'] = {'%s %s %s – %s %s %s', 'd', 'm', 'y', 'd2', 'm2', 'y2'}, -- for long/short reformatting  ['mdy'] = {'%s %s, %s – %s %s, %s', 'm', 'd', 'y', 'm2', 'd2', 'y2'}, -- |df=mdy -> Mdy-Mdy   },  ['Mdy-Mdy'] = { -- date format is Mdy-Mdy; reformat to:  ['mdy'] = {'%s %s, %s – %s %s, %s', 'm', 'd', 'y', 'm2', 'd2', 'y2'}, -- for long/short reformatting  ['dmy'] = {'%s %s %s – %s %s %s', 'd', 'm', 'y', 'd2', 'm2', 'y2'}, -- |df=dmy -> dMy-dMy   },  ['My-My'] = { -- these for long/short reformatting  ['any'] = {'%s %s – %s %s', 'm', 'y', 'm2', 'y2'}, -- dmy/mdy agnostic  },  ['M-My'] = { -- these for long/short reformatting  ['any'] = {'%s–%s %s', 'm', 'm2', 'y'}, -- dmy/mdy agnostic  },  ['My'] = { -- these for long/short reformatting  ['any'] = {'%s %s', 'm', 'y'}, -- dmy/mdy agnostic  }, -- ['yMd'] = { -- not supported at en.wiki -- ['mdy'] = {'%s %s, %s', 'm', 'd', 'y'}, -- |df=mdy -- ['dmy'] = {'%s %s %s', 'd', 'm', 'y'}, -- |df=dmy -- ['ymd'] = {'%s-%s-%s', 'y', 'm', 'd'}, -- |df=ymd -- },  }   local function reformatter (date, pattern_idx, format_param, mon_len)  if not in_array (pattern_idx, {'ymd', 'Mdy', 'Md-dy', 'dMy', 'yMd', 'd-dMy', 'dM-dMy', 'Md-Mdy', 'dMy-dMy', 'Mdy-Mdy', 'My-My', 'M-My', 'My'}) then  return; -- not in this set of date format patterns then not a reformattable date  end   if 'ymd' == format_param and in_array (pattern_idx, {'ymd', 'Md-dy', 'd-dMy', 'dM-dMy', 'Md-Mdy', 'dMy-dMy', 'Mdy-Mdy', 'My-My', 'M-My', 'My'}) then  return; -- ymd date ranges not supported at en.wiki; no point in reformatting ymd to ymd  end   if in_array (pattern_idx, {'My', 'M-My', 'My-My'}) then -- these are not dmy/mdy so can't be 'reformatted' into either  format_param = 'any'; -- so format-agnostic   end  -- if 'yMd' == format_param and in_array (pattern_idx, {'yMd', 'Md-dy', 'd-dMy', 'dM-dMy', 'Md-Mdy', 'dMy-dMy', 'Mdy-Mdy'}) then -- not supported at en.wiki  if 'yMd' == format_param then -- not supported at en.wiki  return; -- not a reformattable date  end   local c1, c2, c3, c4, c5, c6, c7; -- these hold the captures specified in patterns[pattern_idx][1]  c1, c2, c3, c4, c5, c6, c7 = mw.ustring.match (date, patterns[pattern_idx][1]); -- get the captures   local t = { -- table that holds k/v pairs of date parts from the captures and patterns[pattern_idx][2..]  [patterns[pattern_idx][2]] = c1; -- at minimum there is always one capture with a matching indicator letter  [patterns[pattern_idx][3] or 'x'] = c2; -- patterns can have a variable number of captures; each capture requires an indicator letter;  [patterns[pattern_idx][4] or 'x'] = c3; -- where there is no capture, there is no indicator letter so n in patterns[pattern_idx][n] will be nil;  [patterns[pattern_idx][5] or 'x'] = c4; -- the 'x' here spoofs an indicator letter to prevent 'table index is nil' error  [patterns[pattern_idx][6] or 'x'] = c5;  [patterns[pattern_idx][7] or 'x'] = c6;  [patterns[pattern_idx][8] or 'x'] = c7;  };   if t.a then -- if this date has an anchor year capture  t.y = t.a; -- use the anchor year capture when reassembling the date  end   if tonumber(t.m) then -- if raw month is a number (converting from ymd)  if 's' == mon_len then -- if we are to use abbreviated month names  t.m = cfg.date_names['inv_local_s'][tonumber(t.m)]; -- convert it to a month name  else  t.m = cfg.date_names['inv_local_l'][tonumber(t.m)]; -- convert it to a month name  end  t.d = t.d:gsub ('0(%d)', '%1'); -- strip leading '0' from day if present  elseif 'ymd' == format_param then -- when converting to ymd  if 1582 > tonumber(t.y) then -- ymd format dates not allowed before 1582  return;  end  t.m = string.format ('%02d', get_month_number (t.m)); -- make sure that month and day are two digits  t.d = string.format ('%02d', t.d);  elseif mon_len then -- if mon_len is set to either 'short' or 'long'  for _, mon in ipairs ({'m', 'm2'}) do -- because there can be two month names, check both   if t[mon] then  t[mon] = get_month_number (t[mon]); -- get the month number for this month (is length agnostic)  if 0 == t[mon] then return; end -- seasons and named dates can't be converted  t[mon] = (('s' == mon_len) and cfg.date_names['inv_local_s'][t[mon]]) or cfg.date_names['inv_local_l'][t[mon]]; -- fetch month name according to length  end  end  end   local new_date = string.format (re_formats[pattern_idx][format_param][1], -- format string  t[re_formats[pattern_idx][format_param][2]], -- named captures from t{}  t[re_formats[pattern_idx][format_param][3]],  t[re_formats[pattern_idx][format_param][4]],  t[re_formats[pattern_idx][format_param][5]],  t[re_formats[pattern_idx][format_param][6]],  t[re_formats[pattern_idx][format_param][7]],  t[re_formats[pattern_idx][format_param][8]]  );   return new_date; end   --[[-------------------------< R E F O R M A T _ D A T E S >--------------------------------------------------  Reformats existing dates into the format specified by format.  format is one of several manual keywords: dmy, dmy-all, mdy, mdy-all, ymd, ymd-all. The -all version includes access- and archive-dates; otherwise these dates are not reformatted.  This function allows automatic date formatting. In ~/Configuration, the article source is searched for one of the {{use xxx dates}} templates. If found, xxx becomes the global date format as xxx-all. If |cs1-dates= in {{use xxx dates}} has legitimate value then that value determines how cs1|2 dates will be rendered. Legitimate values for |cs1-dates= are:  l - all dates are rendered with long month names  ls - publication dates use long month names; access-/archive-dates use abbreviated month names  ly - publication dates use long month names; access-/archive-dates rendered in ymd format  s - all dates are rendered with abbreviated (short) month names  sy - publication dates use abbreviated month names; access-/archive-dates rendered in ymd format  y - all dates are rendered in ymd format  the format argument for automatic date formatting will be the format specified by {{use xxx dates}} with the value supplied by |cs1-dates so one of: xxx-l, xxx-ls, xxx-ly, xxx-s, xxx-sy, xxx-y, or simply xxx (|cs1-dates= empty, omitted, or invalid) where xxx shall be either of dmy or mdy.  dates are extracted from date_parameters_list, reformatted (if appropriate), and then written back into the list in the new format. Dates in date_parameters_list are presumed here to be valid (no errors). This function returns true when a date has been reformatted, false else. Actual reformatting is done by reformatter().  ]]  local function reformat_dates (date_parameters_list, format)  local all = false; -- set to false to skip access- and archive-dates  local len_p = 'l'; -- default publication date length shall be long  local len_a = 'l'; -- default access-/archive-date length shall be long  local result = false;  local new_date;   if format:match('%a+%-all') then -- manual df keyword; auto df keyword when length not specified in {{use xxx dates}};   format = format:match('(%a+)%-all'); -- extract the format  all = true; -- all dates are long format dates because this keyword doesn't specify length  elseif format:match('%a+%-[lsy][sy]?') then -- auto df keywords; internal only  all = true; -- auto df applies to all dates; use length specified by capture len_p for all dates  format, len_p, len_a = format:match('(%a+)%-([lsy])([sy]?)'); -- extract the format and length keywords  if 'y' == len_p then -- because allowed by MOS:DATEUNIFY (sort of) range dates and My dates not reformatted  format = 'ymd'; -- override {{use xxx dates}}  elseif (not is_set(len_a)) or (len_p == len_a) then -- no access-/archive-date length specified or same length as publication dates then  len_a = len_p; -- in case len_a not set  end  end -- else only publication dates and they are long   for param_name, param_val in pairs (date_parameters_list) do -- for each date-holding parameter in the list  if is_set (param_val.val) then -- if the parameter has a value  if not (not all and in_array (param_name, {'access-date', 'archive-date'})) then -- skip access- or archive-date unless format is xxx-all; yeah, ugly; TODO: find a better way  for pattern_idx, pattern in pairs (patterns) do  if mw.ustring.match (param_val.val, pattern[1]) then  if all and in_array (param_name, {'access-date', 'archive-date'}) then -- if this date is an access- or archive-date  new_date = reformatter (param_val.val, pattern_idx, (('y' == len_a) and 'ymd') or format, len_a); -- choose ymd or dmy/mdy according to len_a setting  else -- all other dates  new_date = reformatter (param_val.val, pattern_idx, format, len_p);  end   if new_date then -- set when date was reformatted  date_parameters_list[param_name].val = new_date; -- update date in date list  result = true; -- and announce that changes have been made  end  end -- if  end -- for  end -- if  end -- if  end -- for return result; -- declare boolean result and done end   --[[--------------------------< D A T E _ H Y P H E N _ T O _ D A S H >----------------------------------------  Loops through the list of date-holding parameters and converts any hyphen to an ndash. Not called if the cs1|2 template has any date errors.  Modifies the date_parameters_list and returns true if hyphens are replaced, else returns false.  ]]  local function date_hyphen_to_dash (date_parameters_list)  local result = false;  local n;  for param_name, param_val in pairs(date_parameters_list) do -- for each date-holding parameter in the list  if is_set (param_val.val) then  if not mw.ustring.match (param_val.val, '%d%d%d%d%-%d%d%-%d%d') then -- for those that are not ymd dates (ustring because here digits may not be western)  param_val.val, n = param_val.val:gsub ('%-', '–'); -- replace any hyphen with ndash  if 0 ~= n then  date_parameters_list[param_name].val = param_val.val; -- update the list  result = true;  end  end  end  end  return result; -- so we know if any hyphens were replaced end   --[[-------------------------< D A T E _ N A M E _ X L A T E >------------------------------------------------  Attempts to translate English month names to local-language month names using names supplied by MediaWiki's date parser function. This is simple name-for-name replacement and may not work for all languages.  if xlat_dig is true, this function will also translate western (English) digits to the local language's digits. This will also translate ymd dates.  ]]  local function date_name_xlate (date_parameters_list, xlt_dig)  local xlate;  local mode; -- long or short month names  local modified = false;  local date;   for param_name, param_val in pairs(date_parameters_list) do -- for each date-holding parameter in the list  if is_set(param_val.val) then -- if the parameter has a value  date = param_val.val;  for month in mw.ustring.gmatch (date, '%a+') do -- iterate through all dates in the date (single date or date range)  if cfg.date_names.en.long[month] then  mode = 'F'; -- English name is long so use long local name  elseif cfg.date_names.en.short[month] then  mode = 'M'; -- English name is short so use short local name  else  mode = nil; -- not an English month name; could be local language month name or an English season name  end   if mode then -- might be a season  xlate = lang_object:formatDate(mode, '1' .. month); -- translate the month name to this local language  date = mw.ustring.gsub (date, month, xlate); -- replace the English with the translation  date_parameters_list[param_name].val = date; -- save the translated date  modified = true;  end  end   if xlt_dig then -- shall we also translate digits?  date = date:gsub ('%d', cfg.date_names.xlate_digits); -- translate digits from western to 'local digits'  date_parameters_list[param_name].val = date; -- save the translated date  modified = true;  end  end  end   return modified;  end   --[[--------------------------< S E T _ S E L E C T E D _ M O D U L E S >--------------------------------------  Sets local imported functions table to same (live or sandbox) as that used by the other modules.  ]]  local function set_selected_modules (cfg_table_ptr, utilities_page_ptr)  is_set = utilities_page_ptr.is_set; -- import functions from selected Module:Citation/CS1/Utilities module  in_array = utilities_page_ptr.in_array; -- import functions from selected Module:Citation/CS1/Utilities module  cfg = cfg_table_ptr; -- import tables from selected Module:Citation/CS1/Configuration end   --[[--------------------------< E X P O R T E D F U N C T I O N S >------------------------------------------ ]]  return { -- return exported functions  dates = dates,  year_date_check = year_date_check,  reformat_dates = reformat_dates,  date_hyphen_to_dash = date_hyphen_to_dash,  date_name_xlate = date_name_xlate,  set_selected_modules = set_selected_modules  }