Module:Citation/CS1/Identifiers

----< F O R W A R D  D E C L A R A T I O N S >--

local has_accept_as_written, is_set, in_array, set_message, select_one,			-- functions in Module:Citation/CS1/Utilities substitute, make_wikilink;

local z;																		-- table of tables defined in Module:Citation/CS1/Utilities

local cfg;																		-- table of configuration tables that are defined in Module:Citation/CS1/Configuration

--[[--< P A G E  S C O P E   V A R I A B L E S >--

declare variables here that have page-wide scope that are not brought in from other modules; that are created here and used here

]]

local auto_link_urls = {};														-- holds identifier URLs for those identifiers that can auto-link |title=

--============================<< H E L P E R  F U N C T I O N S >>============================================

--[[--< W I K I D A T A _ A R T I C L E _ N A M E _ G E T >

as an aid to internationalizing identifier-label wikilinks, gets identifier article names from Wikidata.

returns : : when has an for ; nil else

for identifiers that do not have q, returns nil

for wikis that do not have mw.wikibase installed, returns nil

]]

local function wikidata_article_name_get (q) if not is_set (q) or (q and not mw.wikibase) then							-- when no q number or when a q number but mw.wikibase not installed on this wiki return nil;																-- abandon end

local wd_article; local this_wiki_code = cfg.this_wiki_code;									-- Wikipedia subdomain; 'en' for en.wikipedia.org

wd_article = mw.wikibase.getSitelink (q, this_wiki_code .. 'wiki');			-- fetch article title from WD; nil when no title available at this wiki

if wd_article then wd_article = table.concat ({':', this_wiki_code, ':', wd_article});		-- interwiki-style link without brackets if taken from WD; leading colon required end

return wd_article;															-- article title from WD; nil else end

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

common function to create identifier link label from handler table or from Wikidata

returns the first available of	1. redirect from local wiki's handler table (if enabled) 2. Wikidata (if there is a Wikidata entry for this identifier in the local wiki's language) 3. label specified in the local wiki's handler table ]]

local function link_label_make (handler) local wd_article; if not (cfg.use_identifier_redirects and is_set (handler.redirect)) then	-- redirect has priority so if enabled and available don't fetch from Wikidata because expensive wd_article = wikidata_article_name_get (handler.q);						-- if Wikidata has an article title for this wiki, get it; end return (cfg.use_identifier_redirects and is_set (handler.redirect) and handler.redirect) or wd_article or handler.link; end

--[[--< E X T E R N A L _ L I N K _ I D >--

Formats a wiki-style external link

]]

local function external_link_id (options) local url_string = options.id; local ext_link; local this_wiki_code = cfg.this_wiki_code;									-- Wikipedia subdomain; 'en' for en.wikipedia.org local wd_article;															-- article title from Wikidata if options.encode == true or options.encode == nil then url_string = mw.uri.encode (url_string, 'PATH'); end

if options.auto_link and is_set (options.access) then auto_link_urls[options.auto_link] = table.concat ({options.prefix, url_string, options.suffix}); end

ext_link = mw.ustring.format ('[%s%s%s %s]', options.prefix, url_string, options.suffix or "", mw.text.nowiki (options.id)); if is_set (options.access) then ext_link = substitute (cfg.presentation['ext-link-access-signal'], {cfg.presentation[options.access].class, cfg.presentation[options.access].title, ext_link});	-- add the free-to-read / paywall lock end

return table.concat	({		make_wikilink (link_label_make (options), options.label),				-- redirect, Wikidata link, or locally specified link (in that order)		options.separator or ' ',		ext_link		}); end

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

Formats a wiki-style internal link

TODO: Does not currently need to support options.access, options.encode, auto-linking and COinS (as in external_link_id), but may be needed in the future for :m:Interwiki_map custom-prefixes like :arxiv:, :bibcode:, :DOI:, :hdl:, :ISSN:,
 * JSTOR:, :Openlibrary:, :PMID:, :RFC:.

]]

local function internal_link_id (options) local id = mw.ustring.gsub (options.id, '%d', cfg.date_names.local_digits);	-- translate 'local' digits to Western 0-9

return table.concat (		{		make_wikilink (link_label_make (options), options.label),				-- wiki-link the identifier label		options.separator or ' ',											-- add the separator		make_wikilink ( table.concat (				{				options.prefix,				id,																-- translated to Western digits				options.suffix or ''				}), substitute (cfg.presentation['bdi'], {'', mw.text.nowiki (options.id)})	-- bdi tags to prevent Latin script identifiers from being reversed at RTL language wikis );																	-- nowiki because MediaWiki still has magic links for ISBN and the like; TODO: is it really required?		}); end

--[[--< I S _ E M B A R G O E D >--

Determines if a PMC identifier's online version is embargoed. Compares the date in |pmc-embargo-date= against today's date. If embargo date is in the future, returns the content of |pmc-embargo-date=; otherwise, returns an empty string because the embargo has expired or because |pmc-embargo-date= was not set in this cite.

]]

local function is_embargoed (embargo) if is_set (embargo) then local lang = mw.getContentLanguage; local good1, embargo_date, todays_date; good1, embargo_date = pcall (lang.formatDate, lang, 'U', embargo); todays_date = lang:formatDate ('U'); if good1 then															-- if embargo date is a good date if tonumber (embargo_date) >= tonumber (todays_date) then			-- is embargo date is in the future? return embargo;													-- still embargoed else set_message ('maint_pmc_embargo');								-- embargo has expired; add main cat return '';														-- unset because embargo has expired end end end return '';																	-- |pmc-embargo-date= not set return empty string end

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

for biorxiv, returns true if: 2019-12-11T00:00Z <= biorxiv_date < today + 2 days for medrxiv, returns true if: 2020-01-01T00:00Z <= medrxiv_date < today + 2 days The dated form of biorxiv identifier has a start date of 2019-12-11. The Unix timestamp for that date is = 1576022400 The medrxiv identifier has a start date of 2020-01-01. The Unix timestamp for that date is = 1577836800

 is the date provided in those |biorxiv= parameter values that are dated and in |medrxiv= parameter values at time 00:00:00 UTC is the current date at time 00:00:00 UTC plus 48 hours if today's date is 2023-01-01T00:00:00 then adding 24 hours gives 2023-01-02T00:00:00 – one second more than today adding 24 hours gives 2023-01-03T00:00:00 – one second more than tomorrow

inputs: , ,  – year, month, day parts of the date from the birxiv or medrxiv identifier 'b' for biorxiv, 'm' for medrxiv; defaults to 'b'

]=]

local function is_valid_rxiv_date (y, m, d, select) if 0 == tonumber (m) and 12 < tonumber (m) then								--  must be a number 1–12 return false; end if 0 == tonumber (d) and 31 < tonumber (d) then								--  must be a number 1–31; TODO: account for month length and leap yer? return false; end local rxiv_date = table.concat ({y, m, d}, '-');							-- make ymd date string local good1, good2; local rxiv_ts, tomorrow_ts;													-- to hold Unix timestamps representing the dates local lang_object = mw.getContentLanguage;

good1, rxiv_ts = pcall (lang_object.formatDate, lang_object, 'U', rxiv_date);		-- convert rxiv_date value to Unix timestamp 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 tonumber may not understand rxiv_ts = tonumber (rxiv_ts) or lang_object:parseFormattedNumber (rxiv_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 timestamp end

local limit_ts = ((select and ('m' == select)) and 1577836800) or 1576022400;	-- choose the appropriate limit timesatmp

return ((limit_ts <= rxiv_ts) and (rxiv_ts < tomorrow_ts))					-- limit_ts <= rxiv_date < tomorrow's date end

--[[--< IS _ V A L I D _ I S X N >-

ISBN-10 and ISSN validator code calculates checksum across all ISBN/ISSN digits including the check digit. ISBN-13 is checked in isbn.

If the number is valid the result will be 0. Before calling this function, ISBN/ISSN must be checked for length and stripped of dashes, spaces and other non-ISxN characters.

]]

local function is_valid_isxn (isxn_str, len) local temp = 0; isxn_str = { isxn_str:byte(1, len) };										-- make a table of byte values '0' → 0x30 .. '9' → 0x39, 'X' → 0x58 len = len + 1;																-- adjust to be a loop counter for i, v in ipairs (isxn_str) do											-- loop through all of the bytes and calculate the checksum if v == string.byte ("X" ) then											-- if checkdigit is X (compares the byte value of 'X' which is 0x58) temp = temp + 10 * (len - i);										-- it represents 10 decimal else temp = temp + tonumber (string.char (v) )*(len-i); end end return temp % 11 == 0;														-- returns true if calculation result is zero end

--[[--< IS _ V A L I D _ I S X N _ 1 3 >---

ISBN-13 and ISMN validator code calculates checksum across all 13 ISBN/ISMN digits including the check digit. If the number is valid, the result will be 0. Before calling this function, ISBN-13/ISMN must be checked for length and stripped of dashes, spaces and other non-ISxN-13 characters.

]]

local function is_valid_isxn_13 (isxn_str) local temp=0; isxn_str = { isxn_str:byte(1, 13) };										-- make a table of byte values '0' → 0x30 .. '9' → 0x39 for i, v in ipairs (isxn_str) do		temp = temp + (3 - 2*(i % 2)) * tonumber (string.char (v) );			-- multiply odd index digits by 1, even index digits by 3 and sum; includes check digit end return temp % 10 == 0;														-- sum modulo 10 is zero when ISBN-13/ISMN is correct end

--[[--< N O R M A L I Z E _ L C C N >--

LCCN normalization (https://www.loc.gov/marc/lccn-namespace.html#normalization) 1. Remove all blanks. 2. If there is a forward slash (/) in the string, remove it, and remove all characters to the right of the forward slash. 3. If there is a hyphen in the string: a. Remove it. b. Inspect the substring following (to the right of) the (removed) hyphen. Then (and assuming that steps 1 and 2 have been carried out): 1. All these characters should be digits, and there should be six or less. (not done in this function) 2. If the length of the substring is less than 6, left-fill the substring with zeroes until the length is six.

Returns a normalized LCCN for lccn to validate. There is no error checking (step 3.b.1) performed in this function.

]]

local function normalize_lccn (lccn) lccn = lccn:gsub ("%s", "");												-- 1. strip whitespace

if nil ~= string.find (lccn, '/') then lccn = lccn:match ("(.-)/");											-- 2. remove forward slash and all character to the right of it	end

local prefix local suffix prefix, suffix = lccn:match ("(.+)%-(.+)");									-- 3.a remove hyphen by splitting the string into prefix and suffix

if nil ~= suffix then														-- if there was a hyphen suffix = string.rep("0", 6-string.len (suffix)) .. suffix;				-- 3.b.2 left fill the suffix with 0s if suffix length less than 6 lccn = prefix..suffix;													-- reassemble the LCCN end return lccn; end

--============================<< I D E N T I F I E R  F U N C T I O N S >>====================================

--[[--< A R X I V >

See: https://arxiv.org/help/arxiv_identifier

format and error check arXiv identifier. There are three valid forms of the identifier: the first form, valid only between date codes 9107 and 0703, is: arXiv:. /  where: is a string of alpha characters - may be hyphenated; no other punctuation is a string of alpha characters - may be hyphenated; no other punctuation; not the same as |class= parameter which is not supported in this form is four digits in the form YYMM where YY is the last two digits of the four-digit year and MM is the month number January = 01 first digit of YY for this form can only 9 and 0 is a three-digit number is a 1 or more digit number preceded with a lowercase v; no spaces (undocumented) the second form, valid from April 2007 through December 2014 is: arXiv:. where: is four digits in the form YYMM where YY is the last two digits of the four-digit year and MM is the month number January = 01 is a four-digit number is a 1 or more digit number preceded with a lowercase v; no spaces

the third form, valid from January 2015 is: arXiv:. where: and are as defined for 0704-1412 is a five-digit number

]]

local function arxiv (options) local id = options.id; local class = options.Class;												-- TODO: lowercase? local handler = options.handler; local year, month, version; local err_msg = false;														-- assume no error message local text;																	-- output text if id:match("^%a[%a%.%-]+/[90]%d[01]%d%d%d%d$") or id:match("^%a[%a%.%-]+/[90]%d[01]%d%d%d%dv%d+$") then	-- test for the 9107-0703 format with or without version year, month = id:match("^%a[%a%.%-]+/([90]%d)([01]%d)%d%d%d[v%d]*$"); year = tonumber (year); month = tonumber (month); if ((not (90 year)) or (1 > month or 12 < month)) or		-- if invalid year or invalid month ((91 == year and 7 > month) or (7 == year and 3 < month)) then		-- if years ok, are starting and ending months ok? err_msg = true;													-- flag for error message end

elseif id:match("^%d%d[01]%d%.%d%d%d%d$") or id:match("^%d%d[01]%d%.%d%d%d%dv%d+$") then	-- test for the 0704-1412 with or without version year, month = id:match("^(%d%d)([01]%d)%.%d%d%d%d[v%d]*$"); year = tonumber (year); month = tonumber (month); if ((7 > year) or (14 < year) or (1 > month or 12 < month)) or			-- is year invalid or is month invalid? (doesn't test for future years) ((7 == year) and (4 > month)) then									-- when year is 07, is month invalid (before April)? err_msg = true;													-- flag for error message end

elseif id:match("^%d%d[01]%d%.%d%d%d%d%d$") or id:match("^%d%d[01]%d%.%d%d%d%d%dv%d+$") then	-- test for the 1501- format with or without version year, month = id:match("^(%d%d)([01]%d)%.%d%d%d%d%d[v%d]*$"); year = tonumber (year); month = tonumber (month); if ((15 > year) or (1 > month or 12 < month)) then						-- is year invalid or is month invalid? (doesn't test for future years) err_msg = true;														-- flag for error message end

else err_msg = true;															-- not a recognized format; flag for error message end

if err_msg then options.coins_list_t['ARXIV'] = nil;									-- when error, unset so not included in COinS end local err_msg_t = {}; if err_msg then set_message ('err_bad_arxiv'); end

text = external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,			prefix = handler.prefix, id = id, separator = handler.separator, encode = handler.encode, access = handler.access});

if is_set (class) then if id:match ('^%d+') then text = table.concat ({text, ' [class, ' ', class, ']'});	-- external link within square brackets, not wikilink else set_message ('err_class_ignored'); end end

return text; end

--[[--< B I B C O D E >

Validates (sort of) and formats a bibcode ID.

Format for bibcodes is specified here: https://adsabs.harvard.edu/abs_doc/help_pages/data.html#bibcodes

But, this: 2015arXiv151206696F is apparently valid so apparently, the only things that really matter are length, 19 characters and first four digits must be a year. This function makes these tests: length must be 19 characters characters in position 1–4 must be digits and must represent a year in the range of 1000 – next year 5 must be a letter 6–8 must be letter, digit, ampersand, or dot (ampersand cannot directly precede a dot; &. ) 9–18 must be letter, digit, or dot 19 must be a letter or dot

]]

local function bibcode (options) local id = options.id; local access = options.access; local handler = options.handler; local ignore_invalid = options.accept; local err_type; local err_msg = ''; local year;

local text = external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,		prefix = handler.prefix, id = id, separator = handler.separator, encode = handler.encode,		access = access}); if 19 ~= id:len then err_type = cfg.err_msg_supl.length; else year = id:match ("^(%d%d%d%d)[%a][%w&%.][%w&%.][%w&%.][%w.]+[%a%.]$"); if not year then														-- if nil then no pattern match err_type = cfg.err_msg_supl.value;									-- so value error else local next_year = tonumber (os.date ('%Y')) + 1;					-- get the current year as a number and add one for next year year = tonumber (year);												-- convert year portion of bibcode to a number if (1000 > year) or (year > next_year) then err_type = cfg.err_msg_supl.year;								-- year out of bounds end if id:find('&%.') then err_type = cfg.err_msg_supl.journal;							-- journal abbreviation must not have '&.' (if it does it's missing a letter) end if id:match ('.........%.tmp%.') then								-- temporary bibcodes when positions 10–14 are '.tmp.' set_message ('maint_bibcode'); end end end

if is_set (err_type) and not ignore_invalid then							-- if there was an error detected and accept-as-written markup not used set_message ('err_bad_bibcode', {err_type}); options.coins_list_t['BIBCODE'] = nil;									-- when error, unset so not included in COinS end

return text; end

--[[--< B I O R X I V >-

Format bioRxiv ID and do simple error checking. Before 2019-12-11, biorXiv IDs were 10.1101/ followed by exactly 6 digits. After 2019-12-11, biorXiv IDs retained the six-digit identifier but prefixed that with a yyyy.mm.dd. date and suffixed with an optional version identifier.

The bioRxiv ID is the string of characters: https://doi.org/10.1101/078733 -> 10.1101/078733 or a date followed by a six-digit number followed by an optional version indicator 'v' and one or more digits: https://www.biorxiv.org/content/10.1101/2019.12.11.123456v2 -> 10.1101/2019.12.11.123456v2 see https://www.biorxiv.org/about-biorxiv

]]

local function biorxiv (options) local id = options.id; local handler = options.handler; local err_msg = true;														-- flag; assume that there will be an error local patterns = { '^10%.1101/%d%d%d%d%d%d$',												-- simple 6-digit identifier (before 2019-12-11) '^10%.1101/(20%d%d)%.(%d%d)%.(%d%d)%.%d%d%d%d%d%dv%d+$',				-- y.m.d. date + 6-digit identifier + version (after 2019-12-11) '^10%.1101/(20%d%d)%.(%d%d)%.(%d%d)%.%d%d%d%d%d%d$',					-- y.m.d. date + 6-digit identifier (after 2019-12-11) }	for _, pattern in ipairs (patterns) do										-- spin through the patterns looking for a match if id:match (pattern) then local y, m, d = id:match (pattern);									-- found a match, attempt to get year, month and date from the identifier

if m then															-- m is nil when id is the six-digit form if not is_valid_rxiv_date (y, m, d, 'b') then					-- validate the encoded date; 'b' for biorxiv limit break;														-- date fail; break out early so we don't unset the error message end end err_msg = nil;														-- we found a match so unset the error message break;																-- and done end end																			-- err_cat remains set here when no match

if err_msg then options.coins_list_t['BIORXIV'] = nil;									-- when error, unset so not included in COinS set_message ('err_bad_biorxiv');										-- and set the error message end return external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,			prefix = handler.prefix, id = id, separator = handler.separator,			encode = handler.encode, access = handler.access}); end

--[[--< C I T E S E E R X >

CiteSeerX use their own notion of "doi" (not to be confused with the identifiers resolved via doi.org).

The description of the structure of this identifier can be found at Help_talk:Citation_Style_1/Archive_26#CiteSeerX_id_structure

]]

local function citeseerx (options) local id = options.id; local handler = options.handler; local matched;

local text = external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,		prefix = handler.prefix, id = id, separator = handler.separator, encode = handler.encode,		access = handler.access}); matched = id:match ("^10%.1%.1%.[1-9]%d?%d?%d?%.[1-9]%d?%d?%d?$"); if not matched then set_message ('err_bad_citeseerx' ); options.coins_list_t['CITESEERX'] = nil;								-- when error, unset so not included in COinS end

return text; end

--[[--< D O I >

Formats a DOI and checks for DOI errors.

DOI names contain two parts: prefix and suffix separated by a forward slash. Prefix: directory indicator '10.' followed by a registrant code Suffix: character string of any length chosen by the registrant

This function checks a DOI name for: prefix/suffix. If the DOI name contains spaces or endashes, or, if it ends with a period or a comma, this function will emit a bad_doi error message.

DOI names are case-insensitive and can incorporate any printable Unicode characters so the test for spaces, endash, and terminal punctuation may not be technically correct but it appears, that in practice these characters are rarely if ever used in DOI names.

https://www.doi.org/doi_handbook/2_Numbering.html				-- 2.2 Syntax of a DOI name https://www.doi.org/doi_handbook/2_Numbering.html#2.2.2			-- 2.2.2 DOI prefix

]]

local function doi (options) local id = options.id; local inactive = options.DoiBroken local access = options.access; local ignore_invalid = options.accept; local handler = options.handler; local err_flag;

local text; if is_set (inactive) then local inactive_year = inactive:match("%d%d%d%d");						-- try to get the year portion from the inactive date local inactive_month, good;

if is_set (inactive_year) then if 4 < inactive:len then											-- inactive date has more than just a year (could be anything) local lang_obj = mw.getContentLanguage;						-- get a language object for this wiki good, inactive_month = pcall (lang_obj.formatDate, lang_obj, 'F', inactive);	-- try to get the month name from the inactive date if not good then inactive_month = nil;										-- something went wrong so make sure this is unset end end end																		-- otherwise, |doi-broken-date= has something but it isn't a date if is_set (inactive_year) and is_set (inactive_month) then set_message ('maint_doi_inactive_dated', {inactive_year, inactive_month, ' '}); elseif is_set (inactive_year) then set_message ('maint_doi_inactive_dated', {inactive_year, , }); else set_message ('maint_doi_inactive'); end inactive = " (" .. cfg.messages['inactive'] .. ' ' .. inactive .. ')'; end

local registrant = mw.ustring.match (id, '^10%.([^/]+)/[^%s–]-[^%.,]$');	-- registrant set when DOI has the proper basic form

local registrant_err_patterns = {											-- these patterns are for code ranges that are not supported '^[^1-3]%d%d%d%d%.%d+$',												-- 5 digits with subcode (0xxxx, 40000+); accepts: 10000–39999 '^[^1-6]%d%d%d%d$',														-- 5 digits without subcode (0xxxx, 60000+); accepts: 10000–69999 '^[^1-9]%d%d%d%.%d+$',												-- 4 digits with subcode (0xxx); accepts: 1000–9999 '^[^1-9]%d%d%d$',														-- 4 digits without subcode (0xxx); accepts: 1000–9999 '^%d%d%d%d%d%d+',														-- 6 or more digits '^%d%d?%d?$',															-- less than 4 digits without subcode (3 digits with subcode is legitimate) '^%d%d?%.[%d%.]+',														-- 1 or 2 digits with subcode '^5555$',																-- test registrant will never resolve '[^%d%.]',																-- any character that isn't a digit or a dot }

if not ignore_invalid then if registrant then														-- when DOI has proper form for i, pattern in ipairs (registrant_err_patterns) do				-- spin through error patterns if registrant:match (pattern) then								-- to validate registrant codes err_flag = set_message ('err_bad_doi');						-- when found, mark this DOI as bad break;														-- and done end end else err_flag = set_message ('err_bad_doi');								-- invalid directory or malformed end else set_message ('maint_doi_ignore'); end

if err_flag then options.coins_list_t['DOI'] = nil;										-- when error, unset so not included in COinS end text = external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,		prefix = handler.prefix, id = id, separator = handler.separator, encode = handler.encode, access = access,		auto_link = not (err_flag or is_set (inactive) or ignore_invalid) and 'doi' or nil -- do not auto-link when |doi-broken-date= has a value or when there is a DOI error or (to play it safe, after all, auto-linking is not essential) when invalid DOIs are ignored		}) .. (inactive or '');

return text; end

--[[--< H D L >

Formats an HDL with minor error checking.

HDL names contain two parts: prefix and suffix separated by a forward slash. Prefix: character string using any character in the UCS-2 character set except '/' Suffix: character string of any length using any character in the UCS-2 character set chosen by the registrant

This function checks a HDL name for: prefix/suffix. If the HDL name contains spaces, endashes, or, if it ends with a period or a comma, this function will emit a bad_hdl error message.

HDL names are case-insensitive and can incorporate any printable Unicode characters so the test for endashes and terminal punctuation may not be technically correct but it appears, that in practice these characters are rarely if ever used in HDLs.

Query string parameters are named here: https://www.handle.net/proxy_servlet.html. query strings are not displayed but since '?' is an allowed character in an HDL, '?' followed by one of the query parameters is the only way we have to detect the query string so that it isn't URL-encoded with the rest of the identifier.

]]

local function hdl (options) local id = options.id; local access = options.access; local handler = options.handler; local query_params = {														-- list of known query parameters from https://www.handle.net/proxy_servlet.html 'noredirect', 'ignore_aliases', 'auth', 'cert', 'index', 'type', 'urlappend', 'locatt', 'action', }	local hdl, suffix, param = id:match ('(.-)(%?(%a+).+)$');					-- look for query string local found;

if hdl then																	-- when there are query strings, this is the handle identifier portion for _, q in ipairs (query_params) do									-- spin through the list of query parameters if param:match ('^' .. q) then										-- if the query string begins with one of the parameters found = true;													-- announce a find break;															-- and stop looking end end end

if found then id = hdl;																-- found so replace id with the handle portion; this will be URL-encoded, suffix will not else suffix = '';															-- make sure suffix is empty string for concatenation else end

local text = external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,			prefix = handler.prefix, id = id, suffix = suffix, separator = handler.separator, encode = handler.encode, access = access})

if nil == id:match("^[^%s–]-/[^%s–]-[^%.,]$") then							-- HDL must contain a forward slash, must not contain spaces, endashes, and must not end with period or comma set_message ('err_bad_hdl' ); options.coins_list_t['HDL'] = nil;										-- when error, unset so not included in COinS end

return text; end

--[[--< I S B N >--

Determines whether an ISBN string is valid

]]

local function isbn (options) local isbn_str = options.id; local ignore_invalid = options.accept; local handler = options.handler;

local function return_result (check, err_type)								-- local function to handle the various returns local ISBN = internal_link_id ({link = handler.link, label = handler.label, redirect = handler.redirect,						prefix = handler.prefix, id = isbn_str, separator = handler.separator}); if ignore_invalid then													-- if ignoring ISBN errors set_message ('maint_isbn_ignore');									-- add a maint category even when there is no error else																	-- here when not ignoring if not check then													-- and there is an error options.coins_list_t['ISBN'] = nil;								-- when error, unset so not included in COinS set_message ('err_bad_isbn', err_type);							-- set an error message return ISBN;										 			-- return id text end end return ISBN;															-- return id text end

if nil ~= isbn_str:match ('[^%s-0-9X]') then return return_result (false, cfg.err_msg_supl.char);					-- fail if isbn_str contains anything but digits, hyphens, or the uppercase X	end

local id = isbn_str:gsub ('[%s-]', '');										-- remove hyphens and whitespace

local len = id:len; if len ~= 10 and len ~= 13 then return return_result (false, cfg.err_msg_supl.length);					-- fail if incorrect length end

if len == 10 then if id:match ('^%d*X?$') == nil then										-- fail if isbn_str has 'X' anywhere but last position return return_result (false, cfg.err_msg_supl.form); end if not is_valid_isxn (id, 10) then										-- test isbn-10 for numerical validity return return_result (false, cfg.err_msg_supl.check);				-- fail if isbn-10 is not numerically valid end if id:find ('^63[01]') then												-- 630xxxxxxx and 631xxxxxxx are (apparently) not valid isbn group ids but are used by amazon as numeric identifiers (asin) return return_result (false, cfg.err_msg_supl.group);				-- fail if isbn-10 begins with 630/1 end return return_result (true, cfg.err_msg_supl.check);					-- pass if isbn-10 is numerically valid else if id:match ('^%d+$') == nil then return return_result (false, cfg.err_msg_supl.char);				-- fail if ISBN-13 is not all digits end if id:match ('^97[89]%d*$') == nil then return return_result (false, cfg.err_msg_supl.prefix);				-- fail when ISBN-13 does not begin with 978 or 979 end if id:match ('^9790') then return return_result (false, cfg.err_msg_supl.group);				-- group identifier '0' is reserved to ISMN end return return_result (is_valid_isxn_13 (id), cfg.err_msg_supl.check); end end

--[[--< A S I N >--

Formats a link to Amazon. Do simple error checking: ASIN must be mix of 10 numeric or uppercase alpha characters. If a mix, first character must be uppercase alpha; if all numeric, ASINs must be 10-digit ISBN. If 10-digit ISBN, add a maintenance category so a bot or AWB script can replace |asin= with |isbn=. Error message if not 10 characters, if not ISBN-10, if mixed and first character is a digit.

do not cause this function to emit the maint_asin message
 * asin=630....... and |asin=631....... are (apparently) not a legitimate ISBN though it checksums as one; these

This function is positioned here because it calls isbn

]]

local function asin (options) local id = options.id; local domain = options.ASINTLD; local err_flag;

if not id:match("^[%d%u][%d%u][%d%u][%d%u][%d%u][%d%u][%d%u][%d%u][%d%u][%d%u]$") then err_flag = set_message ('err_bad_asin');								-- ASIN is not a mix of 10 uppercase alpha and numeric characters else if id:match("^%d%d%d%d%d%d%d%d%d[%dX]$") then							-- if 10-digit numeric (or 9 digits with terminal X)			if is_valid_isxn (id, 10) then										-- see if ASIN value is or validates as ISBN-10 if not id:find ('^63[01]') then									-- 630xxxxxxx and 631xxxxxxx are (apparently) not a valid isbn prefixes but are used by amazon as a numeric identifier err_flag = set_message ('err_bad_asin');					-- ASIN has ISBN-10 form but begins with something other than 630/1 so probably an isbn end elseif not is_set (err_flag) then err_flag = set_message ('err_bad_asin');						-- ASIN is not ISBN-10 end elseif not id:match("^%u[%d%u]+$") then err_flag = set_message ('err_bad_asin');							-- asin doesn't begin with uppercase alpha end end if (not is_set (domain)) or in_array (domain, {'us'}) then					-- default: United States domain = "com"; elseif in_array (domain, {'jp', 'uk'}) then									-- Japan, United Kingdom domain = "co." .. domain; elseif in_array (domain, {'z.cn'}) then 									-- China domain = "cn"; elseif in_array (domain, {'au', 'br', 'mx', 'sg', 'tr'}) then				-- Australia, Brazil, Mexico, Singapore, Turkey domain = "com." .. domain; elseif not in_array (domain, {'ae', 'ca', 'cn', 'de', 'es', 'fr', 'in', 'it', 'nl', 'pl', 'sa', 'se', 'co.jp', 'co.uk', 'com', 'com.au', 'com.br', 'com.mx', 'com.sg', 'com.tr'}) then -- Arabic Emirates, Canada, China, Germany, Spain, France, Indonesia, Italy, Netherlands, Poland, Saudi Arabia, Sweden (as of 2021-03 Austria (.at), Liechtenstein (.li) and Switzerland (.ch) still redirect to the German site (.de) with special settings, so don't maintain local ASINs for them) err_flag = set_message ('err_bad_asin_tld');							-- unsupported asin-tld value end local handler = options.handler;

if not is_set (err_flag) then options.coins_list_t['ASIN'] = handler.prefix .. domain .. "/dp/" .. id;	-- asin for coins else options.coins_list_t['ASIN'] = nil;										-- when error, unset so not included in COinS end return external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,		prefix = handler.prefix .. domain .. "/dp/",		id = id, encode = handler.encode, separator = handler.separator}) end

--[[--< I S M N >--

Determines whether an ISMN string is valid. Similar to ISBN-13, ISMN is 13 digits beginning 979-0-... and uses the same check digit calculations. See https://www.ismn-international.org/download/Web_ISMN_Users_Manual_2008-6.pdf section 2, pages 9–12.

ismn value not made part of COinS metadata because we don't have a url or isn't a COinS-defined identifier (rft.xxx) or an identifier registered at info-uri.info (info:)

]]

local function ismn (options) local id = options.id; local handler = options.handler; local text; local valid_ismn = true; local id_copy;

id_copy = id;																-- save a copy because this testing is destructive id = id:gsub ('[%s-]', '');													-- remove hyphens and white space

if 13 ~= id:len or id:match ("^9790%d*$" ) == nil then					-- ISMN must be 13 digits and begin with 9790 valid_ismn = false; else valid_ismn=is_valid_isxn_13 (id);										-- validate ISMN end

--	text = internal_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,		-- use this (or external version) when there is some place to link to	--		prefix = handler.prefix, id = id_copy, separator = handler.separator, encode = handler.encode})

text = table.concat (														-- because no place to link to yet		{		make_wikilink (link_label_make (handler), handler.label),		handler.separator,		id_copy		});

if false == valid_ismn then options.coins_list_t['ISMN'] = nil;										-- when error, unset so not included in COinS; not really necessary here because ismn not made part of COinS set_message ('err_bad_ismn');											-- create an error message if the ISMN is invalid end return text; end

--[[--< I S S N >--

Validate and format an ISSN. This code fixes the case where an editor has included an ISSN in the citation but has separated the two groups of four digits with a space. When that condition occurred, the resulting link looked like this:

|issn=0819 4327 gives: 4327 0819 4327	-- can't have spaces in an external link This code now prevents that by inserting a hyphen at the ISSN midpoint. It also validates the ISSN for length and makes sure that the checkdigit agrees with the calculated value. Incorrect length (8 digits), characters other than 0-9 and X, or checkdigit / calculated value mismatch will all cause a check ISSN error message. The ISSN is always displayed with a hyphen, even if the ISSN was given as a single group of 8 digits.

]]

local function issn (options) local id = options.id; local handler = options.handler; local ignore_invalid = options.accept;

local issn_copy = id;														-- save a copy of unadulterated ISSN; use this version for display if ISSN does not validate local text; local valid_issn = true;

id = id:gsub ('[%s-]', '');													-- remove hyphens and whitespace

if 8 ~= id:len or nil == id:match ("^%d*X?$" ) then						-- validate the ISSN: 8 digits long, containing only 0-9 or X in the last position valid_issn = false;														-- wrong length or improper character else valid_issn = is_valid_isxn (id, 8);										-- validate ISSN end

if true == valid_issn then id = string.sub (id, 1, 4 ) .. "-" .. string.sub (id, 5 );				-- if valid, display correctly formatted version else id = issn_copy;															-- if not valid, show the invalid ISSN with error message end

text = external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,		prefix = handler.prefix, id = id, separator = handler.separator, encode = handler.encode})

if ignore_invalid then set_message ('maint_issn_ignore'); else if false == valid_issn then options.coins_list_t['ISSN'] = nil;									-- when error, unset so not included in COinS set_message ('err_bad_issn', (options.hkey == 'EISSN') and 'e' or '');	-- create an error message if the ISSN is invalid end end return text; end

--[[--< J F M >---

A numerical identifier in the form nn.nnnn.nn

]]

local function jfm (options) local id = options.id; local handler = options.handler; local id_num;

id_num = id:match ('^[Jj][Ff][Mm](.*)$');									-- identifier with jfm prefix; extract identifier

if is_set (id_num) then set_message ('maint_jfm_format'); else																		-- plain number without JFM prefix id_num = id;															-- if here id does not have prefix end

if id_num and id_num:match('^%d%d%.%d%d%d%d%.%d%d$') then id = id_num;															-- jfm matches pattern else set_message ('err_bad_jfm' );											-- set an error message options.coins_list_t['JFM'] = nil;										-- when error, unset so not included in COinS end return external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,			prefix = handler.prefix, id = id, separator = handler.separator, encode = handler.encode}); end

--[[--< J S T O R >

Format a JSTOR with some error checking

]]

local function jstor (options) local id = options.id; local access = options.access; local handler = options.handler;

if id:find ('[Jj][Ss][Tt][Oo][Rr]') or id:find ('^https?://') or id:find ('%s') then set_message ('err_bad_jstor');											-- set an error message options.coins_list_t['JSTOR'] = nil;									-- when error, unset so not included in COinS end return external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,		prefix = handler.prefix, id = id, separator = handler.separator, encode = handler.encode, access = access}); end

--[[--< L C C N >--

Format LCCN link and do simple error checking. LCCN is a character string 8-12 characters long. The length of the LCCN dictates the character type of the first 1-3 characters; the rightmost eight are always digits. https://oclc-research.github.io/infoURI-Frozen/info-uri.info/info:lccn/reg.html

length = 8 then all digits length = 9 then lccn[1] is lowercase alpha length = 10 then lccn[1] and lccn[2] are both lowercase alpha or both digits length = 11 then lccn[1] is lower case alpha, lccn[2] and lccn[3] are both lowercase alpha or both digits length = 12 then lccn[1] and lccn[2] are both lowercase alpha

]]

local function lccn (options) local lccn = options.id; local handler = options.handler; local err_flag;																-- presume that LCCN is valid local id = lccn;															-- local copy of the LCCN

id = normalize_lccn (id);													-- get canonical form (no whitespace, hyphens, forward slashes) local len = id:len;														-- get the length of the LCCN

if 8 == len then if id:match("[^%d]") then												-- if LCCN has anything but digits (nil if only digits) err_flag = set_message ('err_bad_lccn');							-- set an error message end elseif 9 == len then														-- LCCN should be adddddddd if nil == id:match("%l%d%d%d%d%d%d%d%d") then							-- does it match our pattern? err_flag = set_message ('err_bad_lccn');							-- set an error message end elseif 10 == len then														-- LCCN should be aadddddddd or dddddddddd if id:match("[^%d]") then												-- if LCCN has anything but digits (nil if only digits) ... if nil == id:match("^%l%l%d%d%d%d%d%d%d%d") then					-- ... see if it matches our pattern err_flag = set_message ('err_bad_lccn');						-- no match, set an error message end end elseif 11 == len then														-- LCCN should be aaadddddddd or adddddddddd if not (id:match("^%l%l%l%d%d%d%d%d%d%d%d") or id:match("^%l%d%d%d%d%d%d%d%d%d%d")) then	-- see if it matches one of our patterns err_flag = set_message ('err_bad_lccn');							-- no match, set an error message end elseif 12 == len then														-- LCCN should be aadddddddddd if not id:match("^%l%l%d%d%d%d%d%d%d%d%d%d") then						-- see if it matches our pattern err_flag = set_message ('err_bad_lccn');							-- no match, set an error message end else err_flag = set_message ('err_bad_lccn');								-- wrong length, set an error message end

if not is_set (err_flag) and nil ~= lccn:find ('%s') then err_flag = set_message ('err_bad_lccn');								-- lccn contains a space, set an error message end

if is_set (err_flag) then options.coins_list_t['LCCN'] = nil;										-- when error, unset so not included in COinS end

return external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,			prefix = handler.prefix, id = lccn, separator = handler.separator, encode = handler.encode}); end

--[[--< M E D R X I V >-

Format medRxiv ID and do simple error checking. Similar to later bioRxiv IDs, medRxiv IDs are prefixed with a yyyy.mm.dd. date and suffixed with an optional version identifier. Ealiest date accepted is 2020.01.01

The medRxiv ID is a date followed by an eight-digit number followed by an optional version indicator 'v' and one or more digits: https://www.medrxiv.org/content/10.1101/2020.11.16.20232009v2 -> 10.1101/2020.11.16.20232009v2

]]

local function medrxiv (options) local id = options.id; local handler = options.handler; local err_msg_flag = true;													-- flag; assume that there will be an error

local patterns = { '%d%d%d%d%d%d%d%d$',													-- simple 8-digit identifier; these should be relatively rare '^10%.1101/(20%d%d)%.(%d%d)%.(%d%d)%.%d%d%d%d%d%d%d%dv%d+$',			-- y.m.d. date + 8-digit identifier + version (2020-01-01 and later) '^10%.1101/(20%d%d)%.(%d%d)%.(%d%d)%.%d%d%d%d%d%d%d%d$',				-- y.m.d. date + 8-digit identifier (2020-01-01 and later) }	for _, pattern in ipairs (patterns) do										-- spin through the patterns looking for a match if id:match (pattern) then local y, m, d = id:match (pattern);									-- found a match, attempt to get year, month and date from the identifier

if m then															-- m is nil when id is the 8-digit form if not is_valid_rxiv_date (y, m, d, 'b') then					-- validate the encoded date; 'b' for medrxiv limit break;														-- date fail; break out early so we don't unset the error message end end err_msg_flag = nil;													-- we found a match so unset the error message break;																-- and done end end																			--  remains set here when no match

if err_msg_flag then options.coins_list_t['MEDRXIV'] = nil;									-- when error, unset so not included in COinS set_message ('err_bad_medrxiv');										-- and set the error message end return external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,			prefix = handler.prefix, id = id, separator = handler.separator,			encode = handler.encode, access = handler.access}); end

--[[--< M R >--

A seven digit number; if not seven digits, zero-fill leading digits to make seven digits.

]]

local function mr (options) local id = options.id; local handler = options.handler; local id_num; local id_len;

id_num = id:match ('^[Mm][Rr](%d+)$');										-- identifier with mr prefix

if is_set (id_num) then set_message ('maint_mr_format');										-- add maint cat else																		-- plain number without mr prefix id_num = id:match ('^%d+$');											-- if here id is all digits end

id_len = id_num and id_num:len or 0; if (7 >= id_len) and (0 ~= id_len) then id = string.rep ('0', 7-id_len) .. id_num;								-- zero-fill leading digits else set_message ('err_bad_mr');												-- set an error message options.coins_list_t['MR'] = nil;										-- when error, unset so not included in COinS end return external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,			prefix = handler.prefix, id = id, separator = handler.separator, encode = handler.encode}); end

--[[--< O C L C >--

Validate and format an OCLC ID. https://www.oclc.org/batchload/controlnumber.en.html archived at: https://web.archive.org/web/20161228233804/https://www.oclc.org/batchload/controlnumber.en.html

]]

local function oclc (options) local id = options.id; local handler = options.handler; local number;

if id:match('^ocm%d%d%d%d%d%d%d%d$') then									-- ocm prefix and 8 digits; 001 field (12 characters) number = id:match('ocm(%d+)');											-- get the number elseif id:match('^ocn%d%d%d%d%d%d%d%d%d$') then								-- ocn prefix and 9 digits; 001 field (12 characters) number = id:match('ocn(%d+)');											-- get the number elseif id:match('^on%d%d%d%d%d%d%d%d%d%d+$') then							-- on prefix and 10 or more digits; 001 field (12 characters) number = id:match('^on(%d%d%d%d%d%d%d%d%d%d+)$');						-- get the number elseif id:match('^%(OCoLC%)[1-9]%d*$') then									-- (OCoLC) prefix and variable number digits; no leading zeros; 035 field number = id:match('%(OCoLC%)([1-9]%d*)');								-- get the number if 9 < number:len then number = nil;														-- constrain to 1 to 9 digits; change this when OCLC issues 10-digit numbers end elseif id:match('^%d+$') then												-- no prefix number = id;															-- get the number if tonumber (id) > handler.id_limit then number = nil;														-- unset when id value exceeds the limit end end

if number then																-- proper format id = number;															-- exclude prefix, if any, from external link else set_message ('err_bad_oclc')											-- add an error message if the id is malformed options.coins_list_t['OCLC'] = nil;										-- when error, unset so not included in COinS end return external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,		prefix = handler.prefix, id = id, separator = handler.separator, encode = handler.encode}); end

--[[--< O P E N L I B R A R Y >

Formats an OpenLibrary link, and checks for associated errors.

]]

local function openlibrary (options) local id = options.id; local access = options.access; local handler = options.handler; local ident, code = id:gsub('^OL', ''):match("^(%d+([AMW]))$");				-- strip optional OL prefix followed immediately by digits followed by 'A', 'M', or 'W'; local err_flag; local prefix = {															-- these are appended to the handler.prefix according to code ['A']='authors/OL', ['M']='books/OL', ['W']='works/OL', ['X']='OL'																-- not a code; spoof when 'code' in id is invalid };

if not ident then code = 'X';																-- no code or id completely invalid ident = id;																-- copy id to ident so that we display the flawed identifier err_flag = set_message ('err_bad_ol'); end

if not is_set (err_flag) then options.coins_list_t['OL'] = handler.prefix .. prefix[code] .. ident;	-- experiment for ol coins else options.coins_list_t['OL'] = nil;										-- when error, unset so not included in COinS end

return external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,		prefix = handler.prefix .. prefix[code],		id = ident, separator = handler.separator, encode = handler.encode,		access = access}); end

--[[--< O S T I >--

Format OSTI and do simple error checking. OSTIs are sequential numbers beginning at 1 and counting up. This code checks the OSTI to see that it contains only digits and is less than test_limit specified in the configuration; the value in test_limit will need to be updated periodically as more OSTIs are issued.

NB. 1018 is the lowest OSTI number found in the wild (so far) and resolving OK on the OSTI site

]]

local function osti (options) local id = options.id; local access = options.access; local handler = options.handler;

if id:match("[^%d]") then													-- if OSTI has anything but digits set_message ('err_bad_osti');											-- set an error message options.coins_list_t['OSTI'] = nil;										-- when error, unset so not included in COinS else																		-- OSTI is only digits local id_num = tonumber (id);											-- convert id to a number for range testing if 1018 > id_num or handler.id_limit < id_num then						-- if OSTI is outside test limit boundaries set_message ('err_bad_osti');										-- set an error message options.coins_list_t['OSTI'] = nil;									-- when error, unset so not included in COinS end end return external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,			prefix = handler.prefix, id = id, separator = handler.separator, encode = handler.encode, access = access}); end

--[[--< P M C >

Format a PMC, do simple error checking, and check for embargoed articles.

The embargo parameter takes a date for a value. If the embargo date is in the future the PMC identifier will not be linked to the article. If the embargo date is today or in the past, or if it is empty or omitted, then the PMC identifier is linked to the article through the link at cfg.id_handlers['PMC'].prefix.

PMC embargo date testing is done in function is_embargoed which is called earlier because when the citation has |pmc= but does not have a |url= then |title= is linked with the PMC link. Function is_embargoed returns the embargo date if the PMC article is still embargoed, otherwise it returns an empty string.

PMCs are sequential numbers beginning at 1 and counting up. This code checks the PMC to see that it contains only digits and is less than test_limit; the value in local variable test_limit will need to be updated periodically as more PMCs are issued.

]]

local function pmc (options) local id = options.id; local embargo = options.Embargo;											-- TODO: lowercase? local handler = options.handler; local err_flag; local id_num; local text;

id_num = id:match ('^[Pp][Mm][Cc](%d+)$');									-- identifier with PMC prefix

if is_set (id_num) then set_message ('maint_pmc_format'); else																		-- plain number without PMC prefix id_num = id:match ('^%d+$');											-- if here id is all digits end

if is_set (id_num) then														-- id_num has a value so test it		id_num = tonumber (id_num);												-- convert id_num to a number for range testing if 1 > id_num or handler.id_limit < id_num then							-- if PMC is outside test limit boundaries err_flag = set_message ('err_bad_pmc');								-- set an error message else id = tostring (id_num);												-- make sure id is a string end else																		-- when id format incorrect err_flag = set_message ('err_bad_pmc');									-- set an error message end if is_set (embargo) and is_set (is_embargoed (embargo)) then				-- is PMC is still embargoed? text = table.concat (													-- still embargoed so no external link			{			make_wikilink (link_label_make (handler), handler.label),			handler.separator,			id,			}); else text = external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,	-- no embargo date or embargo has expired, ok to link to article			prefix = handler.prefix, id = id, separator = handler.separator, encode = handler.encode, access = handler.access,			auto_link = not err_flag and 'pmc' or nil							-- do not auto-link when PMC has error			}); end

if err_flag then options.coins_list_t['PMC'] = nil;										-- when error, unset so not included in COinS end

return text; end

--[[--< P M I D >--

Format PMID and do simple error checking. PMIDs are sequential numbers beginning at 1 and counting up. This code checks the PMID to see that it contains only digits and is less than test_limit; the value in local variable test_limit will need to be updated periodically as more PMIDs are issued.

]]

local function pmid (options) local id = options.id; local handler = options.handler;

if id:match("[^%d]") then													-- if PMID has anything but digits set_message ('err_bad_pmid');											-- set an error message options.coins_list_t['PMID'] = nil;										-- when error, unset so not included in COinS else																		-- PMID is only digits local id_num = tonumber (id);											-- convert id to a number for range testing if 1 > id_num or handler.id_limit < id_num then							-- if PMID is outside test limit boundaries set_message ('err_bad_pmid');										-- set an error message options.coins_list_t['PMID'] = nil;									-- when error, unset so not included in COinS end end return external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,			prefix = handler.prefix, id = id, separator = handler.separator, encode = handler.encode}); end

--[[--< R F C >

Format RFC and do simple error checking. RFCs are sequential numbers beginning at 1 and counting up. This code checks the RFC to see that it contains only digits and is less than test_limit specified in the configuration; the value in test_limit will need to be updated periodically as more RFCs are issued.

An index of all RFCs is here: https://tools.ietf.org/rfc/

]]

local function rfc (options) local id = options.id; local handler = options.handler;

if id:match("[^%d]") then													-- if RFC has anything but digits set_message ('err_bad_rfc');											-- set an error message options.coins_list_t['RFC'] = nil;										-- when error, unset so not included in COinS else																		-- RFC is only digits local id_num = tonumber (id);											-- convert id to a number for range testing if 1 > id_num or handler.id_limit < id_num then							-- if RFC is outside test limit boundaries set_message ('err_bad_rfc');										-- set an error message options.coins_list_t['RFC'] = nil;									-- when error, unset so not included in COinS end end return external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,			prefix = handler.prefix, id = id, separator = handler.separator, encode = handler.encode, access = handler.access}); end

--[[--< S 2 C I D >

Format an S2CID, do simple error checking

S2CIDs are sequential numbers beginning at 1 and counting up. This code checks the S2CID to see that it is only digits and is less than test_limit; the value in local variable test_limit will need to be updated periodically as more S2CIDs are issued.

]]

local function s2cid (options) local id = options.id; local access = options.access; local handler = options.handler; local id_num; local text; id_num = id:match ('^[1-9]%d*$');											-- id must be all digits; must not begin with 0; no open access flag

if is_set (id_num) then														-- id_num has a value so test it		id_num = tonumber (id_num);												-- convert id_num to a number for range testing if handler.id_limit < id_num then										-- if S2CID is outside test limit boundaries set_message ('err_bad_s2cid');										-- set an error message options.coins_list_t['S2CID'] = nil;								-- when error, unset so not included in COinS end else																		-- when id format incorrect set_message ('err_bad_s2cid');											-- set an error message options.coins_list_t['S2CID'] = nil;									-- when error, unset so not included in COinS end

text = external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,		prefix = handler.prefix, id = id, separator = handler.separator, encode = handler.encode, access = access});

return text; end

--[[--< S B N >

9-digit form of ISBN-10; uses same check-digit validation when SBN is prefixed with an additional '0' to make 10 digits

sbn value not made part of COinS metadata because we don't have a url or isn't a COinS-defined identifier (rft.xxx) or an identifier registered at info-uri.info (info:)

]]

local function sbn (options) local id = options.id; local ignore_invalid = options.accept; local handler = options.handler; local function return_result (check, err_type)								-- local function to handle the various returns local SBN = internal_link_id ({link = handler.link, label = handler.label, redirect = handler.redirect,						prefix = handler.prefix, id = id, separator = handler.separator}); if not ignore_invalid then												-- if not ignoring SBN errors if not check then options.coins_list_t['SBN'] = nil;								-- when error, unset so not included in COinS; not really necessary here because sbn not made part of COinS set_message ('err_bad_sbn', {err_type});						-- display an error message return SBN; end else set_message ('maint_isbn_ignore');									-- add a maint category even when there is no error (ToDo: Possibly switch to separate message for SBNs only) end return SBN; end

if id:match ('[^%s-0-9X]') then return return_result (false, cfg.err_msg_supl.char);					-- fail if SBN contains anything but digits, hyphens, or the uppercase X	end

local ident = id:gsub ('[%s-]', '');										-- remove hyphens and whitespace; they interfere with the rest of the tests

if 9 ~= ident:len then return return_result (false, cfg.err_msg_supl.length);					-- fail if incorrect length end

if ident:match ('^%d*X?$') == nil then return return_result (false, cfg.err_msg_supl.form);					-- fail if SBN has 'X' anywhere but last position end

return return_result (is_valid_isxn ('0' .. ident, 10), cfg.err_msg_supl.check); end

--[[--< S S R N >--

Format an SSRN, do simple error checking

SSRNs are sequential numbers beginning at 100? and counting up. This code checks the SSRN to see that it is only digits and is greater than 99 and less than test_limit; the value in local variable test_limit will need to be updated periodically as more SSRNs are issued.

]]

local function ssrn (options) local id = options.id; local handler = options.handler; local id_num; local text; id_num = id:match ('^%d+$');												-- id must be all digits

if is_set (id_num) then														-- id_num has a value so test it		id_num = tonumber (id_num);												-- convert id_num to a number for range testing if 100 > id_num or handler.id_limit < id_num then						-- if SSRN is outside test limit boundaries set_message ('err_bad_ssrn');										-- set an error message options.coins_list_t['SSRN'] = nil;									-- when error, unset so not included in COinS end else																		-- when id format incorrect set_message ('err_bad_ssrn');											-- set an error message options.coins_list_t['SSRN'] = nil;										-- when error, unset so not included in COinS end text = external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,		prefix = handler.prefix, id = id, separator = handler.separator, encode = handler.encode, access = options.access});

return text; end

--[[--< U S E N E T _ I D >

Validate and format a usenet message id. Simple error checking, looks for 'id-left@id-right' not enclosed in '<' and/or '>' angle brackets.

]]

local function usenet_id (options) local id = options.id; local handler = options.handler;

local text = external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,		prefix = handler.prefix, id = id, separator = handler.separator, encode = handler.encode}) if not id:match('^.+@.+$') or not id:match('^[^<].*[^>]$') then				-- doesn't have '@' or has one or first or last character is '< or '>' set_message ('err_bad_usenet_id')										-- add an error message if the message id is invalid options.coins_list_t['USENETID'] = nil;									-- when error, unset so not included in COinS end return text; end

--[[--< Z B L >---

A numerical identifier in the form nnnn.nnnnn - leading zeros in the first quartet optional

format described here: http://emis.mi.sanu.ac.rs/ZMATH/zmath/en/help/search/

temporary format is apparently eight digits. Anything else is an error

]]

local function zbl (options) local id = options.id; local handler = options.handler;

if id:match('^%d%d%d%d%d%d%d%d$') then										-- is this identifier using temporary format? set_message ('maint_zbl');												-- yes, add maint cat elseif not id:match('^%d?%d?%d?%d%.%d%d%d%d%d$') then						-- not temporary, is it normal format? set_message ('err_bad_zbl');											-- no, set an error message options.coins_list_t['ZBL'] = nil;										-- when error, unset so not included in COinS end return external_link_id ({link = handler.link, label = handler.label, q = handler.q, redirect = handler.redirect,			prefix = handler.prefix, id = id, separator = handler.separator, encode = handler.encode}); end

--============================<< I N T E R F A C E  F U N C T I O N S >>==========================================

--[[--< E X T R A C T _ I D S >

Populates ID table from arguments using configuration settings. Loops through cfg.id_handlers and searches args for any of the parameters listed in each cfg.id_handlers['...'].parameters. If found, adds the parameter and value to the identifier list. Emits redundant error message if more than one alias exists in args

]]

local function extract_ids (args) local id_list = {};															-- list of identifiers found in args for k, v in pairs (cfg.id_handlers) do										-- k is uppercase identifier name as index to cfg.id_handlers; e.g. cfg.id_handlers['ISBN'], v is a table v = select_one (args, v.parameters, 'err_redundant_parameters' );		-- v.parameters is a table of aliases for k; here we pick one from args if present if is_set (v) then id_list[k] = v; end									-- if found in args, add identifier to our list end return id_list; end

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

Fetches custom id access levels from arguments using configuration settings. Parameters which have a predefined access level (e.g. arxiv) do not use this function as they are directly rendered as free without using an additional parameter.

returns a table of k/v pairs where k is same as the identifier's key in cfg.id_handlers and v is the assigned (valid) keyword

access-level values must match the case used in cfg.keywords_lists['id-access'] (lowercase unless there is some special reason for something else)

]]

local function extract_id_access_levels (args, id_list) local id_accesses_list = {}; for k, v in pairs (cfg.id_handlers) do		local access_param = v.custom_access;									-- name of identifier's access-level parameter if is_set (access_param) then local access_level = args[access_param];							-- get the assigned value if there is one if is_set (access_level) then if not in_array (access_level, cfg.keywords_lists['id-access']) then	-- exact match required set_message ('err_invalid_param_val', {access_param, access_level}); access_level = nil;											-- invalid so unset end if not is_set (id_list[k]) then									-- identifier access-level must have a matching identifier set_message ('err_param_access_requires_param', {k:lower});	-- parameter name is uppercase in cfg.id_handlers (k); lowercase for error message end id_accesses_list[k] = cfg.keywords_xlate[access_level];			-- get translated keyword end end end return id_accesses_list; end

--[[--< B U I L D _ I D _ L I S T >

render the identifiers into a sorted sequence table

 is a table of k/v pairs where k is same as key in cfg.id_handlers and v is the assigned value  is a table of various k/v option pairs provided in the call to new_build_id_list; modified by	this function and passed to all identifier rendering functions  is a table of k/v pairs where k is same as key in cfg.id_handlers and v is the assigned value (if valid)

returns a sequence table of sorted (by hkey - 'handler' key) rendered identifier strings

]]

local function build_id_list (ID_list_coins_t, options_t, access_levels_t) local ID_list_t = {}; local accept; local func_map = {															--function map points to functions associated with hkey identifier ['ARXIV'] = arxiv, ['ASIN'] = asin, ['BIBCODE'] = bibcode, ['BIORXIV'] = biorxiv, ['CITESEERX'] = citeseerx, ['DOI'] = doi, ['EISSN'] = issn, ['HDL'] = hdl, ['ISBN'] = isbn, ['ISMN'] = ismn, ['ISSN'] = issn, ['JFM'] = jfm, ['JSTOR'] = jstor, ['LCCN'] = lccn, ['MEDRXIV'] = medrxiv, ['MR'] = mr, ['OCLC'] = oclc, ['OL'] = openlibrary, ['OSTI'] = osti, ['PMC'] = pmc, ['PMID'] = pmid, ['RFC'] = rfc, ['S2CID'] = s2cid, ['SBN'] = sbn, ['SSRN'] = ssrn, ['USENETID'] = usenet_id, ['ZBL'] = zbl, }

for hkey, v in pairs (ID_list_coins_t) do		v, accept = has_accept_as_written (v);									-- remove accept-as-written markup if present; accept is boolean true when markup removed; false else -- every function gets the options table with value v and accept boolean options_t.hkey = hkey;													-- ~/Configuration handler key options_t.id = v;														-- add that identifier value to the options table options_t.accept = accept;												-- add the accept boolean flag options_t.access = access_levels_t[hkey];								-- add the access level for those that have an |<identifier-access= parameter options_t.handler = cfg.id_handlers[hkey]; options_t.coins_list_t = ID_list_coins_t;								-- pointer to ID_list_coins_t; for |asin= and |ol=; also to keep erroneous values out of the citation's metadata options_t.coins_list_t[hkey] = v;										-- id value without accept-as-written markup for metadata if options_t.handler.access and not in_array (options_t.handler.access, cfg.keywords_lists['id-access']) then error (cfg.messages['unknown_ID_access'] .. options_t.handler.access);	-- here when handler access key set to a value not listed in list of allowed id access keywords end

if func_map[hkey] then local id_text = func_map[hkey] (options_t);							-- call the function to get identifier text and any error message table.insert (ID_list_t, {hkey, id_text});							-- add identifier text to the output sequence table else error (cfg.messages['unknown_ID_key'] .. hkey);						-- here when func_map doesn't have a function for hkey end end

local function comp (a, b)													-- used by following table.sort return a[1]:lower < b[1]:lower;										-- sort by hkey end

table.sort (ID_list_t, comp);												-- sequence table of tables sort for k, v in ipairs (ID_list_t) do											-- convert sequence table of tables to simple sequence table of strings ID_list_t[k] = v[2];													-- v[2] is the identifier rendering from the call to the various functions in func_map{} end return ID_list_t; end

--[[--< O P T I O N S _ C H E C K >

check that certain option parameters have their associated identifier parameters with values

 is a table of k/v pairs where k is same as key in cfg.id_handlers and v is the assigned value  is a sequence table of tables created in citation0 where each subtable has four elements: [1] is the support parameter's assigned value; empty string if not set [2] is a text string same as key in cfg.id_handlers [3] is cfg.error_conditions key used to create error message [4] is original ID support parameter name used to create error message returns nothing; on error emits an appropriate error message

]]

local function options_check (ID_list_coins_t, ID_support_t) for _, v in ipairs (ID_support_t) do		if is_set (v[1]) and not ID_list_coins_t[v[2]] then						-- when support parameter has a value but matching identifier parameter is missing or empty set_message (v[3], (v[4]));											-- emit the appropriate error message end end end

--[[--< I D E N T I F I E R _ L I S T S _ G E T >--

Creates two identifier lists: a k/v table of identifiers and their values to be used locally and for use in the COinS metadata, and a sequence table of the rendered identifier strings that will be included in the rendered citation.

]]

local function identifier_lists_get (args_t, options_t, ID_support_t) local ID_list_coins_t = extract_ids (args_t);										-- get a table of identifiers and their values for use locally and for use in COinS options_check (ID_list_coins_t, ID_support_t);										-- ID support parameters must have matching identifier parameters local ID_access_levels_t = extract_id_access_levels (args_t, ID_list_coins_t);		-- get a table of identifier access levels local ID_list_t = build_id_list (ID_list_coins_t, options_t, ID_access_levels_t);	-- get a sequence table of rendered identifier strings

return ID_list_t, ID_list_coins_t;											-- return the tables end

--[[--< S E T _ S E L E C T E D _ M O D U L E S >--

Sets local cfg table and 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) cfg = cfg_table_ptr;

has_accept_as_written = utilities_page_ptr.has_accept_as_written;			-- import functions from select Module:Citation/CS1/Utilities module is_set = utilities_page_ptr.is_set; in_array = utilities_page_ptr.in_array; set_message = utilities_page_ptr.set_message; select_one = utilities_page_ptr.select_one; substitute = utilities_page_ptr.substitute; make_wikilink = utilities_page_ptr.make_wikilink;

z = utilities_page_ptr.z;													-- table of tables in Module:Citation/CS1/Utilities end

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

return { auto_link_urls = auto_link_urls,											-- table of identifier URLs to be used when auto-linking |title= identifier_lists_get = identifier_lists_get,								-- experiment to replace individual calls to build_id_list, extract_ids, extract_id_access_levels is_embargoed = is_embargoed; set_selected_modules = set_selected_modules; }