Modul:URIutil

 local URIutil = { suite = "URIutil",
 serial = "2024年08月05日",
 item = 19644443 };
 --[=[
 Utilities for URI etc.
 * coreISSN()
 * formatISBN()
 * formatISSN()
 * formatLCCN()
 * isDNBvalid()
 * isDOI()
 * isEscValid()
 * isGTINvalid()
 * isHandle()
 * isISBN()
 * isISBNvalid()
 * isISSNvalid()
 * isLCCN()
 * linkDNBopac()
 * linkDOI()
 * linkHandle()
 * linkISBN()
 * linkISSN()
 * linkLCCN()
 * linkPMID()
 * linkURN()
 * mayDOI()
 * mayHandle()
 * mayISBN()
 * mayISSN()
 * mayLCCN()
 * mayURI()
 * mayURN()
 * plainISBN()
 * targetISSN()
 * uriDOI()
 * uriHandle()
 * uriURN()
 * failsafe()
 * URIutil()
 loadData: URIutil/config URIutil/isbn URIutil/urn
 ]=]
 local Failsafe = URIutil;
 local CurrentPageName;



 local factory = function ( attempt, allowX )
 -- Retrieve plain digits of attempt
 -- Precondition:
 -- attempt -- string; with digits (+xX) and hyphens, not trimmed
 -- allowX -- number; of (last) position for permitted xX
 -- boolean; xX at last position permitted
 -- Postcondition:
 -- Returns table; success
 -- [1]...[8]/[10]...[13] -- digits 0...9
 -- 10 at last position
 -- .hyphens -- number of hyphens
 -- .type -- number of digits
 -- number; no string or bad length or data
 -- 0 -- no string
 -- >0 -- unexpected char at position (trimmed)
 local r;
 if type( attempt ) == "string" then
 local c, i;
 local j = 0;
 local k = 1;
 local s = mw.text.trim( attempt );
 local n = mw.ustring.len( s );
 r = { hyphens = 0 };
 for i = 1, n do
 c = mw.ustring.codepoint( s, i, i + 1 );
 if c >= 48 and c <= 57 then
 j = j + 1;
 r[ j ] = c - 48;
 k = false;
 elseif c == 45 then -- hyphen
 if i > 1 and i < n then
 r.hyphens = r.hyphens + 1;
 k = i;
 else
 r = j;
 break;
 end
 elseif c == 88 or c == 120 then -- X x
 j = j + 1;
 if allowX and i == n then
 if allowX == true or allowX == j then
 r[ j ] = 10;
 else
 r = j;
 end
 else
 r = j;
 end
 break;
 else
 r = j;
 break;
 end
 end -- for i
 if type( r ) == "table" then
 r.type = j;
 end
 else
 r = 0;
 end
 return r;
 end -- factory()



 local faculty = function ( ask, auto )
 -- Evaluate possible string as boolean signal, if brief
 -- Precondition:
 -- ask -- trimmed string or nil or other
 -- auto -- fallback value if nil
 -- Postcondition:
 -- Returns appropriate value, or ask
 local r;
 if type( ask ) == "string" then
 if ask == "1" or ask == "" then
 r = true;
 elseif ask == "0" or ask == "-" then
 r = false;
 else
 r = ask;
 end
 elseif ask == nil then
 r = auto;
 else
 r = ask;
 end
 return r;
 end -- faculty()



 local fair = function ( assert )
 -- Compute check digit (11 minus modulo 11) for descending factor
 -- Precondition:
 -- assert -- table; as of factory()
 -- .type -- number of digits including check digit
 -- Postcondition:
 -- Returns checksum
 local i;
 local n = assert.type;
 local k = n;
 local r = 0;
 for i = 1, n - 1 do
 r = r + k * assert[ i ];
 k = k - 1;
 end -- for i
 return ( 11 - r % 11 );
 end -- fair()



 local fault = function ( alert )
 -- Format error message by class=error
 -- Parameter:
 -- alert -- string, error message
 -- Returns:
 -- string, HTML span
 return tostring( mw.html.create( "span" )
 :addClass( "error" )
 :wikitext( alert ) );
 end -- fault()



 local fetch = function ( acquire )
 -- Load data submodule
 -- Precondition:
 -- acquire -- string, one of
 -- "config"
 -- "isbn"
 -- "urn"
 -- Postcondition:
 -- Returns any table
 local r;
 if URIutil.data then
 r = URIutil.data[ acquire ];
 else
 URIutil.data = { };
 end
 if not r then
 local lucky, storage;
 storage = "Module:URIutil/" .. acquire;
 lucky, r = pcall( mw.loadData, storage );
 if not lucky then
 if not URIutil.suited and
 type( URIutil.item ) == "number" then
 local suited = string.format( "Q%d", URIutil.item );
 URIutil.suited = mw.wikibase.getSitelink( suited )
 or true;
 end
 if type( URIutil.suited ) == "string" then
 storage = string.format( "%s/%s",
 URIutil.suited, acquire );
 lucky, r = pcall( mw.loadData, storage );
 end
 end
 if type( r ) ~= "table" then
 r = { };
 end
 URIutil.data[ acquire ] = r;
 end
 return r;
 end -- fetch()



 local flop = function ( alert )
 -- Create link to (maintenance) category
 -- Precondition:
 -- alert -- trimmed string with title, not empty, or nil
 -- Postcondition:
 -- Returns link, or false
 local r;
 if type( alert ) == "string" and
 alert ~= "-" and
 alert ~= "" then
 r = string.format( "[[Category:%s]]", alert );
 end
 return r;
 end -- flop()



 local format = function ( assigned, ahead, amount )
 -- Convert part of digit sequence into string
 -- Precondition:
 -- assigned -- table; as of factory()
 -- ahead -- index of first digit
 -- amount -- number of digits to append
 -- Postcondition:
 -- Returns string with digits and hyphens
 local i, k;
 local r = "";
 for i = ahead, ahead + amount - 1 do
 k = assigned[ i ];
 if k == 10 then
 r = r .. "X";
 else
 r = r .. tostring( k );
 end
 end -- for i
 return r;
 end -- format()



 local fullPageName = function ()
 -- Retrieve current page name
 -- Postcondition:
 -- Returns string: current page name
 if not CurrentPageName then
 CurrentPageName = mw.title.getCurrentTitle().fullText;
 end
 return CurrentPageName;
 end -- fullPageName()



 local DNBfaith = function ( assert, ancestor )
 -- Compute DNB (also GND, ZDB) check digit and verify
 -- Precondition:
 -- assert -- table; as of factory()
 -- .type -- until 11 including check digit
 -- ancestor -- true: 2011 mode
 -- Postcondition:
 -- Returns true: check digit matches
 -- 2013年09月01日
 local k = fair( assert ) % 11;
 if ancestor then
 k = 11 - k;
 end
 return ( k == assert[ assert.type ] );
 end -- DNBfaith()



 local GTINfair = function ( assert )
 -- Compute GTIN check digit
 -- Precondition:
 -- assert -- table; ~ 13 digits
 -- .type -- 13 ...
 -- Postcondition:
 -- Returns number 0...9
 local i, k;
 local lead = true;
 local r = 0;
 for i = 1, assert.type - 1 do
 k = assert[ i ];
 r = r + k;
 if lead then -- odd
 lead = false;
 else -- even
 r = r + k + k;
 lead = true;
 end
 end -- for i
 r = (10 - r % 10) % 10;
 return r;
 end -- GTINfair()



 local GTINfaith = function ( assert )
 -- Compute GTIN check digit and verify
 -- Precondition:
 -- assert -- table; ~ 13 digits
 -- .type -- 13 ...
 -- Postcondition:
 -- Returns true: check digit matches
 return ( GTINfair( assert ) == assert[ assert.type ] );
 end -- GTINfaith()



 local ISBNfactory = function ( attempt )
 -- Retrieve plain digits of ISBN attempt
 -- Precondition:
 -- attempt -- string with digits (+xX) and hyphens, not trimmed
 -- Postcondition:
 -- Returns table; success
 -- [1]...[13] -- digits 0...9
 -- 10 at ISBN-10 last position
 -- .type -- 10 or 13
 -- .hyphens -- 0... number of hyphens
 -- number; no string or bad length or data
 -- 0 -- no string
 -- >0 -- unexpected char at position (trimmed)
 -- -1 -- bad digit count
 -- -2 -- bad bookland
 local r;
 if type( attempt ) == "string" then
 local s;
 r = factory( attempt, 10 );
 s = type( r );
 if s == "number" and r ~= 10 and r > 6 and r < 13 then
 r = factory( attempt, r );
 s = type( r );
 end
 if s == "table" then
 if r.type == 13 then
 if r[1] ~= 9 or
 r[2] ~= 7 or
 r[3] < 8 then
 r = -2;
 end
 elseif r.type ~= 10 then
 r = -1;
 end
 end
 else
 r = 0;
 end
 return r;
 end -- ISBNfactory()



 local ISBNfaith = function ( assert )
 -- Compute ISBN check digit and verify
 -- Precondition:
 -- assert -- table; as of ISBNfactory()
 -- .type -- 10 or 13
 -- Postcondition:
 -- Returns true: check digit matches
 local r;
 if assert.type == 10 then
 local i;
 local k = 0;
 for i = 1, 9 do
 k = k + i * assert[ i ];
 end -- for i
 k = k % 11;
 r = ( k == assert[ 10 ] );
 elseif assert.type == 13 then
 r = GTINfaith( assert );
 else
 r = false;
 end
 return r;
 end -- ISBNfaith()



 local ISBNflat = function ( assigned )
 -- Plain digits of attempt ISBN
 -- Precondition:
 -- assigned -- table; as of ISBNfactory()
 -- Postcondition:
 -- Returns string with digits; ISBN-10 with 'X' at last position
 local i;
 local r = "";
 local n = assigned.type;
 if n == 10 then
 if assigned[ assigned.type ] == 10 then
 n = 9;
 end
 end
 for i = 1, n do
 r = r .. tostring( assigned[ i ] );
 end -- for i
 if n == 9 then
 r = r .. "X";
 end
 return r;
 end -- ISBNflat()



 local ISBNfold = function ( assigned, apply, allocate, already )
 -- Retrieve number of digits for ISBN publisher/group
 -- Precondition:
 -- assigned -- table; as of ISBNfactory()
 -- apply -- number; of bookland (978 or 979)
 -- allocate -- number; of country
 -- already -- number; position in assigned to inspect
 -- Postcondition:
 -- Returns number of digits, at least 0
 local r = 0;
 local def = fetch( "isbn" );
 local bookland = def[ apply ];
 if type( bookland ) == "table" then
 local country = bookland[ allocate ];
 if type( country ) == "table" then
 local e, i, j, k, m, v;
 for i = 1, 4 do
 v = country[ i ];
 if type( v ) == "table" then
 m = tonumber( format( assigned, already, i ) );
 for k, e in pairs( v ) do
 if m >= e[ 1 ] and m <= e[ 2 ] then
 r = e[ 3 ];
 break; -- for k
 end
 end -- for k
 end
 if r > 0 then
 break; -- for i
 end
 end -- for i
 end
 end
 return r;
 end -- ISBNfold()



 local ISBNformat = function ( attempt, assigned )
 -- Hyphen formatting; at least try minimum
 -- Precondition:
 -- attempt -- string with presumable ISBN
 -- assigned -- table; as of ISBNfactory()
 -- .type -- 10 or 13
 -- .hyphens -- 0...4
 -- Postcondition:
 -- Returns string with digits and hyphens
 local r = false;
 local j, k, m, n;
 if assigned.type == 10 then
 m = 978;
 r = "";
 j = 1;
 else
 m = 970 + assigned[ 3 ];
 r = tostring( m ) .. "-";
 j = 4;
 end
 if assigned[ j ] < 8 then
 k = 1;
 else
 k = 2;
 if assigned[ j ] == 9 and
 assigned[ j + 1 ] > 4 then
 k = 3;
 if assigned[ j + 1 ] > 8 then
 k = 4;
 if assigned[ j + 2 ] > 8 then
 k = 5;
 end
 end
 end
 end
 if k then
 n = format( assigned, j, k );
 r = string.format( "%s%s-", r, n );
 j = j + k;
 n = ISBNfold( assigned, m, tonumber( n ), j );
 if n > 0 then
 r = string.format( "%s%s-", r, format( assigned, j, n ) );
 j = j + n;
 end
 end
 r = r .. format( assigned, j, assigned.type - j );
 if assigned[ assigned.type ] == 10 then
 r = r .. "-X";
 else
 r = string.format( "%s-%s",
 r,
 tostring( assigned[ assigned.type ] ) );
 end
 if not r then
 r = mw.ustring.upper( mw.text.trim( attempt ) );
 end
 return r;
 end -- ISBNformat()



 local ISSNfactory = function ( attempt )
 -- Retrieve plain digits of ISSN attempt
 -- Precondition:
 -- attempt -- string with digits (+xX) and hyphens, not trimmed
 -- Postcondition:
 -- Returns table; success
 -- [1]...[13] -- digits 0...9
 -- 10 at ISSN-8 last position
 -- .type -- 8 or 13
 -- .hyphens -- 0... number of hyphens
 -- number; no string or bad length or data
 -- 0 -- no string
 -- >0 -- unexpected char at position (trimmed)
 -- -1 -- bad digit count
 -- -2 -- bad issnland
 local r;
 if type( attempt ) == "string" then
 r = factory( attempt, 8 );
 if type( r ) == "table" then
 if r.type == 13 then
 if r[1] ~= 9 or
 r[2] ~= 7 or
 r[3] ~= 7 then
 r = -2;
 end
 elseif r.type ~= 8 then
 r = -1;
 end
 end
 else
 r = 0;
 end
 return r;
 end -- ISSNfactory()



 local ISSNfaith = function ( assert )
 -- Compute ISSN check digit and verify
 -- Precondition:
 -- assert -- table; as of ISSNfactory()
 -- .type -- 8 or 13
 -- Postcondition:
 -- Returns true: check digit matches
 local r;
 if assert.type == 8 then
 local k = fair( assert );
 if k == 11 then
 r = ( assert[ 8 ] == 0 );
 else
 r = ( assert[ 8 ] == k );
 end
 elseif assert.type == 13 then
 r = GTINfaith( assert );
 else
 r = false;
 end
 return r;
 end -- ISSNfaith()



 local ISSNformat = function ( assigned, achieve )
 -- Hyphen formatting of ISSN
 -- Precondition:
 -- assigned -- table; as of ISSNfactory(), and valid
 -- achieve -- 8 or 13
 -- Postcondition:
 -- Returns string with digits and hyphens
 local r;
 if achieve == 8 then
 local x;
 if assigned.type == 8 then
 r = string.format( "%s-%s",
 format( assigned, 1, 4 ),
 format( assigned, 5, 3 ) );
 x = assigned[ 8 ];
 elseif assigned.type == 13 then
 r = string.format( "%s-%s",
 format( assigned, 4, 4 ),
 format( assigned, 8, 3 ) );
 x = fair( assigned );
 end
 if x == 10 then
 r = r .. "X";
 else
 r = r .. tostring( x );
 end
 elseif achieve == 13 then
 if assigned.type == 8 then
 r = string.format( "977-%s-00-%s",
 format( assigned, 1, 7 ),
 GTINfair( assigned ) );
 elseif assigned.type == 13 then
 r = string.format( "977-%s%s-%s",
 format( assigned, 4, 7 ),
 format( assigned, 10, 2 ),
 tostring( assigned[ 13 ] ) );
 end
 end
 return r;
 end -- ISSNformat()



 local LCCNfactory = function ( attempt, allow )
 -- Retrieve segments of LCCN attempt (format since 2001)
 -- Precondition:
 -- attempt -- string with presumable LCCN
 -- allow -- false or string: "/"
 -- Postcondition:
 -- Returns table; success
 -- false if not correct, bad data
 -- 2014年12月28日
 local r = false;
 local pat = "^%s*(%a*)(/?)(%d%S+)%s*$";
 local pre, sep, s = attempt:match( pat );
 if pre and s then
 local year, serial;
 if pre == "" then
 pre = false;
 if sep ~= "" then
 s = false;
 end
 elseif #pre > 3 then
 s = false;
 else
 pre = pre:lower();
 end
 if s then
 if allow ~= "/" or sep == "/" then
 if sep == "/" then
 year, serial = s:match( "^(%d+)/(%d.+)$" );
 elseif s:find( "-", 2, true ) then
 year, serial = s:match( "^(%d+)%-(%d.+)$" );
 else
 year = s:match( "^([%d]+)" );
 if year then
 if #year <= 8 then
 year = s:sub( 1, 2 );
 serial = s:sub( 3 );
 elseif #year <= 10 then
 year = s:sub( 1, 4 );
 serial = s:sub( 5 );
 else
 year = false;
 serial = s;
 end
 elseif tonumber( s ) then
 serial = s;
 end
 end
 end
 if year then
 if #year == 4 then
 local n = tonumber( year );
 if n <= 2000 then
 -- 2000 -> "00"
 serial = false;
 elseif n > tonumber( os.date( "%Y" ) ) then
 serial = false;
 end
 elseif #year ~= 2 then
 serial = false;
 end
 end
 if serial then
 r = { pre = pre, serial = serial };
 if year then
 r.year = year;
 end
 if serial:find( "/", 2, true ) then
 local q;
 serial, q = serial:lower()
 :match( "^(%d+)/([a-z]+)$" );
 if q == "dc" or
 q == "mads" or
 q == "marcxml" or
 q == "mods" then
 r.serial = serial;
 r.qualifier = q;
 end
 end
 if serial then
 serial = serial:match( "^0*([1-9]%d*)$" );
 end
 if not serial then
 r = false;
 elseif #serial < 6 then
 r.serial = string.format( "%06d",
 tonumber( serial ) );
 elseif #serial > 6 then
 r = false;
 end
 end
 end
 end
 return r;
 end -- LCCNfactory()



 local LCCNformat = function ( assigned, achieve )
 -- Standard or hyphen or slash formatting of LCCN
 -- Precondition:
 -- assigned -- table; as of LCCNfactory(), and valid
 -- achieve -- additional formatting desires, like "-" or "/"
 -- Postcondition:
 -- Returns string with letters, digits and hyphens
 -- 2013年07月14日
 local r;
 if assigned.pre then
 r = assigned.pre;
 else
 r = "";
 end
 if assigned.year then
 if achieve == "/" and r ~= "" then
 r = r .. "/";
 end
 r = r .. assigned.year;
 if achieve then
 r = r .. achieve;
 end
 end
 if assigned.serial then
 r = r .. assigned.serial;
 end
 if assigned.qualifier then
 r = string.format( "%s/%s", r, assigned.qualifier );
 end
 return r;
 end -- LCCNformat()



 local LCCNforward = function ( attempt, achieve )
 -- Retrieve bracketed titled external LCCN permalink
 -- Precondition:
 -- attempt -- string with presumable LCCN
 -- achieve -- additional title formatting desires, like "-"
 -- Postcondition:
 -- Returns link, or plain attempt if bad LCCN
 -- 2015年08月10日
 local lccn = LCCNfactory( attempt );
 local r;
 if lccn then
 r = LCCNformat( lccn, false );
 if r then
 local e, s;
 if achieve then
 s = LCCNformat( lccn, achieve );
 if s:find( "-", 2, true ) then
 e = mw.html.create( "span" )
 :css( "white-space", "nowrap" );
 end
 else
 s = r;
 end
 s = string.format( "[https://lccn.loc.gov/%s %s]", r, s );
 if e then
 r = tostring( e:wikitext( s ) );
 else
 r = s;
 end
 end
 else
 r = attempt;
 end
 return r;
 end -- LCCNforward()



 local URNnamespace = function ( area, acquire )
 -- Are these parts of a correct URN?
 -- Precondition:
 -- area -- string with lowercase namespace
 -- acquire -- string with identification
 -- Postcondition:
 -- Returns false if no problem detected
 -- string with violation
 local r;
 if area == "urn" then
 r = "urn:";
 else
 local s = fetch( "urn" ).sns;
 if type( s ) == "string" then
 r = string.format( ":%s:", area );
 if s:match( r ) then
 s = "[^%w%(%)%+,%-%.:=/@;%$_!%*'].*$";
 r = acquire:match( s );
 else
 r = string.format( "&#58;%s:", area );
 end
 if not r then
 r = false;
 if area == "isbn" then
 if not URIutil.isISBNvalid( acquire ) then
 r = acquire;
 end
 elseif area == "issn" then
 if not URIutil.isISSNvalid( acquire ) then
 r = acquire;
 end
 end
 end
 end
 end
 return r;
 end -- URNnamespace()



 local URNresolve = function ( assigned, ask, alter )
 -- Resolve URN within space
 -- Precondition:
 -- assigned -- table with resolvers for this space
 -- ask -- string with ID within this space
 -- alter -- string with alternative resolver, or not
 -- Postcondition:
 -- Returns
 -- 1. URL of resolver, or nil
 -- 2. modified ask
 local resolver = assigned;
 local sign = ask;
 local subset = assigned[ ":" ];
 local r;
 if subset then
 local s = sign:match( subset );
 if s then
 s = s:lower();
 sign = s .. sign:sub( #s + 1 )
 if assigned[ s ] then
 resolver = assigned[ s ];
 end
 end
 end
 if alter then
 r = resolver[ alter ];
 end
 if not r then
 r = resolver[ "*" ];
 end
 return r, sign;
 end -- URNresolve()



 function URIutil.coreISSN( attempt )
 -- Fetch significant ISSN
 -- Precondition:
 -- attempt -- string with presumable ISSN
 -- Postcondition:
 -- Returns string with 7 digits, without check digit nor GTIN
 -- unmodified input if wrong
 local r;
 local issn = ISSNfactory( attempt );
 if type( issn ) == "table" then
 if issn.type == 8 then
 r = format( issn, 1, 7 );
 elseif issn.type == 13 then
 r = format( issn, 4, 7 );
 end
 else
 r = mw.ustring.upper( mw.text.trim( attempt ) );
 end
 return r;
 end -- URIutil.coreISSN()



 function URIutil.formatISBN( attempt, assigned )
 -- Format ISBN, if no hyphens present
 -- Precondition:
 -- attempt -- string with presumable ISBN
 -- assigned -- table or false; as of ISBNfactory()
 -- Postcondition:
 -- Returns string with some hyphens, if not yet
 -- unmodified input if already hyphens or wrong
 local r;
 local isbn;
 if type( assigned ) == "table" then
 isbn = assigned;
 else
 isbn = ISBNfactory( attempt );
 end
 if type( isbn ) == "table" then
 r = ISBNformat( attempt, isbn );
 else
 r = mw.ustring.upper( mw.text.trim( attempt ) );
 end
 return r;
 end -- URIutil.formatISBN()



 function URIutil.formatISSN( attempt, achieve )
 -- Format ISSN
 -- Precondition:
 -- attempt -- string with presumable ISSN
 -- achieve -- false or 8 or 13; requested presentation
 -- Postcondition:
 -- Returns string with some hyphens, if not yet
 -- unmodified input if already hyphens or wrong
 local r = false;
 local issn = ISSNfactory( attempt );
 if type( issn ) == "table" then
 if ISSNfaith( issn ) then
 local k, m;
 if type( achieve ) == "string" then
 m = tonumber( achieve );
 else
 m = achieve;
 end
 if m == 8 or m == 13 then
 k = m;
 else
 k = issn.type;
 end
 r = ISSNformat( issn, k );
 end
 end
 if not r then
 r = mw.ustring.upper( mw.text.trim( attempt ) );
 end
 return r;
 end -- URIutil.formatISSN()



 function URIutil.formatLCCN( attempt, achieve )
 -- Standard or hyphen formatting of LCCN
 -- Precondition:
 -- attempt -- string with presumable LCCN
 -- achieve -- additional formatting desires, like "-"
 -- Postcondition:
 -- Returns string with letters, digits and hyphens
 -- unmodified input if wrong
 local r = LCCNfactory( attempt );
 if r then
 r = LCCNformat( r, achieve );
 end
 return r;
 end -- URIutil.formatLCCN()



 function URIutil.isDNBvalid( attempt, also )
 -- Is this DNB (also GND, ZDB) formally correct (check digit)?
 -- Precondition:
 -- attempt -- string with any presumable DNB code
 -- also -- string or nil; optional requirement DMA GND SWD
 -- "ZDB" -- permit hyphen, but use >2011 rule
 -- DMA starting with 3 and no hyphen
 -- GND not DNB2011
 -- SWD DNB2011 starting with 4 or 7 and no X check
 -- Postcondition:
 -- Returns number of digits or 2011, if valid
 -- false if not correct, bad data or check digit wrong
 local s = mw.text.trim( attempt );
 local j = s:find( "/", 5, true );
 local r = false;
 local dnb;
 if j then
 s = attempt:sub( 1, j - 1 );
 end
 j = s:find( "-", 2, true );
 if j then
 if j > 3 and j <= 8 then
 if s:match( "^[0-9]+-[0-9xX]$" ) then
 dnb = factory( s, true );
 end
 end
 elseif #s > 6 then
 if s:match( "^[0-9]+[0-9xX]$" ) then
 dnb = factory( s, #s );
 end
 end
 if type( dnb ) == "table" then
 if j then
 if DNBfaith( dnb, true ) then
 r = 2011;
 elseif type( also ) == "string" then
 s = mw.text.trim( also );
 if s == "ZDB" then
 if DNBfaith( dnb, false ) then
 r = dnb.type;
 end
 end
 end
 else
 if DNBfaith( dnb, false ) then
 r = dnb.type;
 elseif type( also ) == "string" then
 s = mw.text.trim( also );
 if s == "ZDB" then
 if DNBfaith( dnb, true ) then
 r = dnb.type;
 end
 end
 end
 end
 end
 return r;
 end -- URIutil.isDNBvalid()



 function URIutil.isDOI( attempt )
 -- Is this a syntactically correct DOI?
 -- Precondition:
 -- attempt -- string with presumable DOI code
 -- Postcondition:
 -- Returns number of organization, if valid
 -- false if not correct, bad character or syntax
 local r = false;
 if not URIutil.DOIpAuth then
 URIutil.DOIpAuth = "^%s*10%.([1-9][0-9]+)/(.+)%s*$";
 end
 local k, s = attempt:match( URIutil.DOIpAuth );
 if k then
 k = tonumber( k );
 if k >= 1000 and k < 100000000 then
 if not URIutil.DOI then
 URIutil.DOIpID = "^[0-9A-Za-z%(%[<%./]"
 .. "[%-0-9/A-Z%.a-z%(%)_%[%];,:<>%+]*"
 .. "[0-9A-Za-z%)%]>%+#]$";
 end
 s = mw.uri.decode( mw.text.decode( s ), "PATH" );
 if s:match( URIutil.DOIpID ) or s:match( "^%w$" ) then
 r = k;
 end
 end
 end
 return r;
 end -- URIutil.isDOI()



 function URIutil.isEscValid( attempt )
 -- Are bad percent escapings in attempt?
 -- Precondition:
 -- attempt -- string with possible percent escapings
 -- Postcondition:
 -- Returns string with violating sequence
 -- false if correct
 local i = 0;
 local r = false;
 local h, s;
 while i do
 i = attempt:find( "%", i, true );
 if i then
 s = attempt:sub( i + 1, i + 2 );
 h = s:match( "%x%x" );
 if h then
 if h == "00" then
 r = "%00";
 break; -- while i
 end
 i = i + 2;
 else
 r = "%" .. s;
 break; -- while i
 end
 end
 end -- while i
 return r;
 end -- URIutil.isEscValid()



 function URIutil.isGTINvalid( attempt )
 -- Is this GTIN (EAN) formally correct (check digit)?
 -- Precondition:
 -- attempt -- string with presumable GTIN
 -- Postcondition:
 -- Returns GTIN length
 -- false if not correct, bad data or check digit wrong
 local r;
 local gtin = factory( attempt, false );
 if type( gtin ) == "table" then
 if gtin.type == 13 then
 if GTINfaith( gtin ) then
 r = gtin.type;
 end
 else
 r = false;
 end
 else
 r = false;
 end
 return r;
 end -- URIutil.isGTINvalid()



 function URIutil.isHandle( attempt )
 -- Is this a meaningful handle for handle.net?
 -- Precondition:
 -- attempt -- string with presumable handle code
 -- Postcondition:
 -- Returns number of primary authority, if valid
 -- false if not correct, bad character or syntax
 local r = attempt:match( "^%s*([^/%s]+)/%S+%s*$" );
 if r then
 local k = r:find( ".", 1, true );
 if k then
 if k == 1 or r:match( "%.$" ) then
 r = false;
 else
 r = r:sub( 1, k - 1 );
 end
 end
 if r then
 if r:match( "^[1-9][0-9]+$" ) then
 r = tonumber( r );
 else
 r = false;
 end
 end
 else
 r = false;
 end
 return r;
 end -- URIutil.isHandle()



 function URIutil.isISBN( attempt )
 -- Is this a syntactically correct ISBN?
 -- Precondition:
 -- attempt -- string with presumable ISBN
 -- Postcondition:
 -- Returns
 -- 1 -- 10 if 10 digits and hyphens; also X at end of ISBN-10
 -- 13 if 13 digits and hyphens; beginning with bookland
 -- false if not an ISBN
 -- 2 -- internal table, if (1)
 -- number; no string or bad length or data
 -- 0 -- no string
 -- >0 -- unexpected char at position (trimmed)
 -- -1 -- bad digit count
 -- -2 -- bad bookland
 local r;
 local isbn = ISBNfactory( attempt );
 if type( isbn ) == "table" then
 r = isbn.type;
 else
 r = false;
 end
 return r, isbn;
 end -- URIutil.isISBN()



 function URIutil.isISBNvalid( attempt )
 -- Is this ISBN formally correct (check digit)?
 -- Precondition:
 -- attempt -- string with presumable ISBN
 -- Postcondition:
 -- Returns
 -- 1 -- 10 if 10 digits and hyphens; also X at end of ISBN-10
 -- 13 if 13 digits and hyphens; beginning with bookland
 -- false if not correct, bad data or check digit wrong
 -- 2 -- internal table, if (1)
 -- number; no string or bad length or data
 -- 0 -- no string
 -- >0 -- unexpected char at position (trimmed)
 -- -1 -- bad digit count
 -- -2 -- bad bookland
 local r = false;
 local isbn = ISBNfactory( attempt );
 if type( isbn ) == "table" then
 if ISBNfaith( isbn ) then
 r = isbn.type;
 end
 end
 return r, isbn;
 end -- URIutil.isISBNvalid()



 function URIutil.isISSNvalid( attempt )
 -- Is this ISSN formally correct (check digit)?
 -- Precondition:
 -- attempt -- string with presumable ISSN
 -- Postcondition:
 -- Returns 8 if 8 digits and up to 1 hyphen; also X at end
 -- 13 if 13 digits and hyphens; beginning with 977
 -- false if not correct, bad data or check digit wrong
 local r = false;
 local issn = ISSNfactory( attempt );
 if type( issn ) == "table" then
 if ISSNfaith( issn ) then
 r = issn.type;
 end
 end
 return r;
 end -- URIutil.isISSNvalid()



 function URIutil.isLCCN( attempt, allow )
 -- Is this a syntactically correct LCCN?
 -- Precondition:
 -- attempt -- string with presumable LCCN
 -- allow -- false or string: "/"
 -- Postcondition:
 -- Returns string with LCCN formatted aa9999-99999999
 -- false if not correct, bad data
 local r = false;
 local lccn = LCCNfactory( attempt, allow );
 if lccn then
 r = LCCNformat( lccn, "-" );
 end
 return r;
 end -- URIutil.isLCCN()



 function URIutil.linkDNBopac( attempt, about, allow, abbr, alert )
 -- Retrieve bracketed titled external DNB opac link
 -- Precondition:
 -- attempt -- string with presumable DNB ID
 -- about -- title, or false
 -- allow -- true: permit invalid ID
 -- abbr -- true: link DNB abbreviation
 -- alert -- string with title of maintenance category, or nil
 -- Postcondition:
 -- Returns link, or plain string if bad DNB
 local r = allow or URIutil.isDNBvalid( attempt );
 local s = "DNB";
 if abbr and not about then
 local cnf = fetch( "config" );
 if cnf.supportDNB and cnf.supportDNB ~= fullPageName() then
 s = string.format( "[[%s|DNB]]", cnf.supportDNB );
 end
 end
 if r then
 if about then
 r = about;
 else
 r = attempt;
 end
 r = string.format( "%s&nbsp;[%s%s%s%s%s %s]",
 s,
 "https://portal.dnb.de/opac.htm",
 "?referrer=Wikipedia",
 "&method=simpleSearch&cqlMode=true",
 "&query=idn%3D",
 attempt,
 r );
 else
 r = string.format( "%s&nbsp;%s", s, attempt );
 if about then
 r = string.format( "%s %s", r, about );
 end
 if alert then
 r = r .. flop( alert );
 end
 end
 return r;
 end -- URIutil.linkDNBopac()



 function URIutil.linkDOI( attempt, any1, any2, any3, alert )
 -- Retrieve bracketed titled external link on DOI resolver
 -- Precondition:
 -- attempt -- string with presumable DOI
 -- any1 -- intentionally dummy parameter
 -- any2 -- intentionally dummy parameter
 -- any3 -- intentionally dummy parameter
 -- alert -- string with title of maintenance category, or nil
 -- Postcondition:
 -- Returns external link, or false
 local r = URIutil.isDOI( attempt );
 if r then
 local e = mw.html.create( "span" )
 :addClass( "uri-handle" )
 :css( "white-space", "nowrap" );
 local s;
 s, r = attempt:match( "^%s*(10%.[1-9][0-9]+/)(.+)%s*$" );
 r = mw.text.decode( r, "PATH" );
 r = string.format( "[%s/%s%s %s%s]",
 "https://doi.org",
 s,
 mw.uri.encode( r ):gsub( "#$", "%23" ),
 s,
 mw.text.encode( r, "<>&%]" ) );
 r = tostring( e:wikitext( r ) );
 else
 r = flop( alert );
 end
 return r;
 end -- URIutil.linkDOI()



 function URIutil.linkHandle( attempt, any1, any2, any3, alert )
 -- Retrieve bracketed titled external link on handle resolver
 -- Precondition:
 -- attempt -- string with presumable handle
 -- any1 -- intentionally dummy parameter
 -- any2 -- intentionally dummy parameter
 -- any3 -- intentionally dummy parameter
 -- alert -- string with title of maintenance category, or nil
 -- Postcondition:
 -- Returns external link, or false
 local r = URIutil.isHandle( attempt );
 if r then
 local e = mw.html.create( "span" )
 :addClass( "uri-handle" )
 :css( "white-space", "nowrap" );
 r = mw.text.decode( mw.text.trim( attempt ), "PATH" );
 r = string.format( "[%s%s %s]",
 "https://hdl.handle.net/",
 mw.uri.encode( r ),
 mw.text.encode( r, "<>&%]" ) );
 r = tostring( e:wikitext( r ) );
 else
 r = flop( alert );
 end
 return r;
 end -- URIutil.linkHandle()



 function URIutil.linkISBN( attempt, allow, abbr, adhere, alert )
 -- Retrieve bracketed titled wikilink on booksources page with "ISBN"
 -- Precondition:
 -- attempt -- string with presumable ISBN
 -- allow -- true: permit invalid check digit or digit count
 -- abbr -- true or string: link ISBN abbreviation
 -- adhere -- true: use &nbsp; else: use simple space
 -- alert -- string with title of maintenance category, or nil
 -- Postcondition:
 -- Returns link
 local e = mw.html.create( "span" );
 local source = mw.text.trim( attempt );
 local r = string.format( "[[Special:Booksources/%s|", source );
 local isbn = ISBNfactory( source );
 local lapsus;
 if type( isbn ) == "table" then
 local lenient;
 if type( allow ) == "string" then
 lenient = ( allow ~= "0" );
 else
 lenient = allow;
 end
 if lenient then
 lapsus = false;
 else
 lapsus = ( not ISBNfaith( isbn ) );
 end
 r = r .. ISBNformat( attempt, isbn );
 else
 lapsus = not allow;
 r = r .. source;
 end
 r = r .. "]]";
 e:css( "white-space", "nowrap" );
 if lapsus then
 r = r .. fault( "(?!?!)" );
 e:addClass( "invalid-ISBN" )
 :wikitext( r );
 r = tostring( e );
 if alert then
 r = r .. flop( alert );
 end
 else
 e:wikitext( r );
 r = tostring( e );
 end
 if adhere then
 r = "&nbsp;" .. r;
 else
 r = " " .. r;
 end
 if abbr then
 local cnf = fetch( "config" );
 local s = cnf.supportISBN;
 if s then
 if type( s ) ~= "string"
 or s == "-"
 or s == "" then
 s = false;
 end
 else
 s = "International Standard Book Number";
 end
 if s and s ~= fullPageName() then
 s = string.format( "[[%s|ISBN]]", s );
 else
 s = "ISBN";
 end
 r = string.format( "%s&#160;%s", s, r );
 else
 r = "ISBN" .. r;
 end
 return r;
 end -- URIutil.linkISBN()



 function URIutil.linkISSN( attempt, allow, abbr, adhere, alert )
 -- Retrieve bracketed titled external link on ISSN DB with "ISSN"
 -- Precondition:
 -- attempt -- string with presumable ISSN
 -- allow -- true: permit invalid check digit
 -- abbr -- true: link ISSN abbreviation
 -- adhere -- true: use &nbsp; else: use simple space;
 -- alert -- string with title of maintenance category, or nil
 -- Postcondition:
 -- Returns link
 local r = URIutil.targetISSN( attempt, allow, nil, nil, alert );
 if adhere then
 r = "&#160;" .. r;
 else
 r = " " .. r;
 end
 if abbr then
 local cnf = fetch( "config" );
 local s = cnf.supportISSN;
 if s then
 if type( s ) ~= "string"
 or s == "-"
 or s == "" then
 s = false;
 end
 else
 s = "International Standard Serial Number";
 end
 if s and s ~= fullPageName() then
 if s == "ISSN" then
 s = "[[ISSN]]";
 else
 s = string.format( "[[%s|ISSN]]", s );
 end
 else
 s = "ISSN";
 end
 r = string.format( "%s%s", s, r );
 else
 r = "ISSN" .. r;
 end
 return r;
 end -- URIutil.linkISSN()



 function URIutil.linkLCCN( attempt, achieve, any1, any2, alert )
 -- Retrieve bracketed titled external LCCN permalink
 -- Precondition:
 -- attempt -- string with presumable LCCN
 -- achieve -- additional title formatting desires, like "-"
 -- any1 -- intentionally dummy parameter
 -- any2 -- intentionally dummy parameter
 -- alert -- string with title of maintenance category, or nil
 -- Postcondition:
 -- Returns link, or false if bad LCCN
 local r = LCCNforward( attempt, achieve );
 if not r then
 r = flop( alert );
 end
 return r;
 end -- URIutil.linkLCCN()



 function URIutil.linkPMID( attempt, any, abbr, adhere, alert )
 -- Retrieve external PMID link with "PMID"
 -- Precondition:
 -- attempt -- string or number with presumable PMID
 -- any -- intentionally dummy parameter
 -- abbr -- true: link PMID abbreviation
 -- adhere -- true: use &nbsp; else: use simple space;
 -- alert -- string with title of maintenance category, or nil
 -- Postcondition:
 -- Returns link
 local s = type( attempt );
 local legal, r;
 if s == "string" then
 r = mw.text.trim( attempt );
 if r == "" then
 r = "PMID";
 s = "empty";
 end
 elseif s == "number" then
 r = tostring( attempt );
 s = "string";
 else
 r = "PMID";
 end
 if s == "string" then
 legal = r:match( "^[1-9]%d*$" );
 if legal then
 local cnf = fetch( "config" );
 if cnf then
 s = cnf.pmid;
 if type( s ) == "string" and
 s ~= "-" and
 s ~= "" then
 local sep;
 if s:find( "1ドル", 5, true ) then
 s = s:gsub( "%1ドル", r );
 else
 s = s .. r;
 end
 r = string.format( "[%s %s]", s, r );
 if adhere then
 sep = "&#160;";
 else
 sep = " ";
 end
 if abbr then
 s = cnf.supportPMID;
 if type( s ) == "string" and
 s ~= "-" and
 s ~= "" and
 s ~= fullPageName() then
 if s == "PMID" then
 s = "[[PMID]]";
 else
 s = string.format( "[[%s|PMID]]", s );
 end
 else
 s = "PMID";
 end
 else
 s = "PMID";
 end
 r = string.format( "%s%s%s", s, sep, r );
 else
 cnf = false;
 end
 end
 if not cnf then
 r = string.format( "PMID %s", r );
 end
 else
 r = string.format( "PMID %s", r );
 end
 end
 if not legal then
 local e = mw.html.create( "span" )
 :addClass( "invalid-PMID" )
 :wikitext( r );
 r = tostring( e ) .. fault( "(?!?!)" );
 if alert then
 r = r .. flop( alert );
 end
 end
 return r;
 end -- URIutil.linkPMID()



 function URIutil.linkURN( attempt, alter, any1, any2, alert, at, alone )
 -- Retrieve bracketed titled external URN link
 -- Precondition:
 -- attempt -- string, with presumable URN, starting with "urn:"
 -- alter -- alternative handler
 -- any1 -- intentionally dummy parameter
 -- any2 -- intentionally dummy parameter
 -- alert -- string, with title of maintenance category, or nil
 -- at -- fragment, or nil
 -- alone -- true, if link text not preceded by "urn:"
 -- Postcondition:
 -- Returns
 -- 1. linked ID, or plain string if bad URN
 -- 2. true, if to be preceded by "urn:"
 local r2 = true;
 local r;
 if URIutil.mayURN( attempt ) then
 local e = mw.html.create( "span" )
 :addClass( "invalid-URN" );
 local serial = attempt;
 local suffix = flop( alert );
 if serial:sub( 1, 4 ):lower() == "urn:" then
 serial = serial:sub( 5 );
 end
 e:wikitext( serial );
 r = tostring( e ) .. fault( "(?!?!)" );
 if suffix then
 r = r .. suffix;
 end
 else
 local s = attempt:match( "^%s*[uU][rR][nN]:(%S+)%s*$" );
 if s then
 local space, sign = s:match( "^(%w+):(.+)$" );
 if space then
 local defs = fetch( "urn" );
 if type( defs ) == "table" then
 local resolver = defs.resolver;
 space = space:lower();
 resolver = resolver[ space ];
 r2 = ( resolver ~= true );
 if type( resolver ) == "table" then
 r, sign = URNresolve( resolver, sign, alter );
 s = string.format( "%s:%s", space, sign );
 if r then
 r = r:gsub( "%1ドル", "urn:" .. s );
 if at then
 r = string.format( "%s#%s", r, at );
 end
 if alone then
 r2 = true;
 else
 s = "urn:" .. s;
 end
 r = string.format( "[%s %s]", r, s );
 end
 elseif r2 then
 if type( defs.sns ) == "string" then
 s = string.format( ":%s:", space );
 if not defs.sns:find( s, 1, true ) then
 s = false;
 end
 else
 s = false;
 end
 if s then
 r = string.format( "%s:%s", space, sign );
 else
 r = string.format( "%s&#58;%s",
 space, sign );
 end
 r2 = not alone;
 else
 s = "link" .. space:upper();
 r = URIutil[ s ]( sign, alter, nil, nil, alert );
 end
 else
 r = fault( "Bad structure in Module:URIutil/urn" );
 end
 end
 end
 end
 if not r then
 if alert then
 r = flop( alert ) or "";
 if attempt then
 r = attempt .. r;
 end
 else
 r = mw.text.trim( attempt );
 end
 r2 = false;
 end
 return r, r2;
 end -- URIutil.linkURN()



 function URIutil.mayDOI( attempt )
 -- Is this a syntactically correct DOI, or empty?
 -- Precondition:
 -- attempt -- string with presumable DOI
 -- Postcondition:
 -- Returns number of organization
 -- 0 if empty
 -- false if not empty and not a DOI
 local r;
 if type( attempt ) == "string" then
 local s = mw.text.trim( attempt );
 if #s >= 10 then
 r = URIutil.isDOI( attempt );
 elseif #s == 0 then
 r = 0;
 else
 r = false;
 end
 else
 r = false;
 end
 return r;
 end -- URIutil.mayDOI()



 function URIutil.mayHandle( attempt )
 -- Is this a meaningful handle, or empty?
 -- Precondition:
 -- attempt -- string with presumable handle
 -- Postcondition:
 -- Returns number of organization
 -- 0 if empty
 -- false if not empty and not a DOI
 local r;
 if type( attempt ) == "string" then
 local s = mw.text.trim( attempt );
 if #s > 5 then
 r = URIutil.isHandle( attempt );
 elseif #s == 0 then
 r = 0;
 else
 r = false;
 end
 else
 r = false;
 end
 return r;
 end -- URIutil.mayHandle()



 function URIutil.mayISBN( attempt )
 -- Is this a syntactically correct ISBN, or empty?
 -- Precondition:
 -- attempt -- string with presumable ISBN
 -- Postcondition:
 -- Returns 10 if 10 digits and hyphens; also X at end of ISBN-10
 -- 13 if 13 digits and hyphens; beginning with bookland
 -- 0 if empty
 -- false if not empty and not an ISBN
 local r;
 if type( attempt ) == "string" then
 local s = mw.text.trim( attempt );
 if #s >= 10 then
 r = URIutil.isISBN( attempt );
 elseif #s == 0 then
 r = 0;
 else
 r = false;
 end
 else
 r = false;
 end
 return r;
 end -- URIutil.mayISBN()



 function URIutil.mayISSN( attempt )
 -- Is this a correct ISSN, or empty?
 -- Precondition:
 -- attempt -- string with presumable ISSN
 -- Postcondition:
 -- Returns 8 if 8 digits and hyphens; also X at end
 -- 13 if 13 digits and hyphens; beginning with issnland
 -- 0 if empty
 -- false if not empty and not an ISSN
 local r;
 if type( attempt ) == "string" then
 local s = mw.text.trim( attempt );
 if #s >= 8 then
 r = URIutil.isISSNvalid( attempt );
 elseif #s == 0 then
 r = 0;
 else
 r = false;
 end
 else
 r = false;
 end
 return r;
 end -- URIutil.mayISSN()



 function URIutil.mayLCCN( attempt )
 -- Is this a syntactically correct LCCN?
 -- Precondition:
 -- attempt -- string with presumable LCCN
 -- Postcondition:
 -- Returns string with LCCN formatted aa9999-99999999
 -- 0 if empty
 -- false if not recognized
 local r;
 if type( attempt ) == "string" then
 local s = mw.text.trim( attempt );
 if s == "" then
 r = 0;
 else
 r = URIutil.isLCCN( s );
 end
 else
 r = false;
 end
 return r;
 end -- URIutil.mayLCCN()



 function URIutil.mayURI( attempt, ascii )
 -- Is this a syntactically correct URI, or empty?
 -- Precondition:
 -- attempt -- string with presumable URI
 -- ascii -- limit to ASCII (no IRI)
 -- Postcondition:
 -- Returns false if no problem
 -- string with violation
 local r = URIutil.isEscValid( attempt );
 if not r then
 local s = mw.text.trim( attempt );
 r = s:match( "%s(.+)$" );
 if not r then
 r = s:match( "#(.*)$" );
 if r then
 r = "&#35;" .. r;
 elseif ascii then
 local p = string.format( "[%s].+$",
 mw.ustring.char( 128,45,255 ) );
 r = mw.ustring.match( s, p );
 end
 end
 end
 return r;
 end -- URIutil.mayURI()



 function URIutil.mayURN( attempt )
 -- Is this a syntactically correct URN, or empty?
 -- Precondition:
 -- attempt -- string with presumable URN, starting with "urn:"
 -- Postcondition:
 -- Returns false if no problem
 -- string with violation
 local r = URIutil.mayURI( attempt, true );
 if not r then
 local s = attempt:match( "^%s*[uU][rR][nN]:(.+)$" );
 if s then
 local space, id = s:match( "^(%w+):(.+)$" );
 if space then
 r = URNnamespace( space:lower(), id );
 else
 r = s;
 end
 else
 s = mw.text.trim( attempt );
 if s == "" then
 r = false;
 elseif s:match( "^https?://" ) then
 r = "http:";
 else
 r = "urn:";
 end
 end
 end
 return r;
 end -- URIutil.mayURN()



 function URIutil.plainISBN( attempt )
 -- Format ISBN as digits (and 'X') only string
 -- Precondition:
 -- attempt -- string with presumable ISBN
 -- Postcondition:
 -- Returns string with 10 or 13 chars
 -- false if not empty and not an ISBN
 local r;
 local isbn = ISBNfactory( attempt );
 if type( isbn ) == "table" then
 r = ISBNflat( isbn );
 else
 r = false;
 end
 return r;
 end -- URIutil.plainISBN()



 function URIutil.targetISSN( attempt, allow, any1, any2, alert )
 -- Retrieve bracketed titled external link on ISSN DB without "ISSN"
 -- Precondition:
 -- attempt -- string with presumable ISSN
 -- allow -- true: permit invalid check digit
 -- any1 -- intentionally dummy parameter
 -- any2 -- intentionally dummy parameter
 -- alert -- string with title of maintenance category, or nil
 -- Postcondition:
 -- Returns link
 local e = mw.html.create( "span" );
 local cnf = fetch( "config" );
 local issn = ISSNfactory( attempt );
 local lapsus, r;
 if type( issn ) == "table" then
 local lenient;
 if type( allow ) == "string" then
 lenient = ( allow ~= "0" );
 else
 lenient = allow;
 end
 if lenient then
 lapsus = false;
 else
 lapsus = ( not ISSNfaith( issn ) );
 end
 r = ISSNformat( issn, issn.type );
 if type( cnf.issn ) == "string" then
 local s = cnf.issn
 if s:find( "1ドル", 5, true ) then
 s = s:gsub( "%1ドル", r );
 else
 s = s .. r;
 end
 r = string.format( "[%s %s]", s, r );
 end
 else
 lapsus = true;
 r = attempt;
 end
 e:css( "white-space", "nowrap" )
 :wikitext( r );
 if lapsus then
 e:addClass( "invalid-ISSN" );
 r = tostring( e ) .. fault( "(?!?!)" );
 if alert then
 r = r .. flop( alert );
 end
 else
 r = tostring( e );
 end
 return r;
 end -- URIutil.targetISSN()



 function URIutil.uriDOI( attempt, anything, abbr )
 -- Retrieve linked URI on DOI resolver
 -- Precondition:
 -- attempt -- string with presumable DOI
 -- anything -- intentionally dummy parameter
 -- abbr -- true or string: link doi: abbreviation
 local r = URIutil.linkDOI( attempt );
 if r then
 if abbr then
 local s;
 if type( abbr ) == "string" then
 s = abbr;
 else
 s = "Digital Object Identifier";
 end
 if s ~= fullPageName() then
 r = string.format( "[[%s|doi]]:%s", s, r );
 else
 r = "doi:" .. r;
 end
 else
 r = "doi:" .. r;
 end
 end
 return r;
 end -- URIutil.uriDOI()



 function URIutil.uriHandle( attempt, anything, abbr )
 -- Retrieve linked URI on handle resolver
 -- Precondition:
 -- attempt -- string with presumable handle
 -- anything -- intentionally dummy parameter
 -- abbr -- true or string: link hdl: abbreviation
 -- Postcondition:
 -- Returns combined linked URI, or false
 local r = URIutil.linkHandle( attempt );
 if r then
 local s;
 if type( abbr ) == "string" then
 s = abbr;
 else
 local cnf = fetch( "config" );
 if cnf then
 s = cnf.supportHandle;
 if type( s ) ~= "string" or
 s == "-" or
 s == "" or
 s == fullPageName() then
 s = false;
 end
 end
 end
 if s then
 r = string.format( "[[%s|hdl]]:%s", s, r );
 else
 r = "hdl:" .. r;
 end
 end
 return r;
 end -- URIutil.uriHandle()



 function URIutil.uriURN( attempt, anything, alter, alert, at )
 -- Retrieve linked URI on URN resolver
 -- Precondition:
 -- attempt -- string with presumable URN, starting with "urn:"
 -- anything -- intentionally dummy parameter
 -- alter -- string with alternative handler, or nil
 -- alert -- string with title of maintenance category, or nil
 -- at -- fragment, or nil
 -- Postcondition:
 -- Returns link, or plain string if bad URN
 local r, l =
 URIutil.linkURN( attempt, alter, false, false, alert, at, true );
 if l then
 local s = fetch( "config" ).supportURN;
 if s then
 if type( s ) ~= "string"
 or s == "-"
 or s == "" then
 s = false;
 end
 else
 s = "Uniform Resource Name";
 end
 if s and s ~= fullPageName() then
 r = string.format( "[[%s|urn]]:%s", s, r );
 else
 r = "urn:" .. r;
 end
 end
 return r;
 end -- URIutil.uriURN()



 Failsafe.failsafe = function ( atleast )
 -- Retrieve versioning and check for compliance
 -- Precondition:
 -- atleast -- string, with required version
 -- or wikidata|item|~|@ or false
 -- Postcondition:
 -- Returns string -- with queried version/item, also if problem
 -- false -- if appropriate
 -- 2024年03月01日
 local since = atleast
 local last = ( since == "~" )
 local linked = ( since == "@" )
 local link = ( since == "item" )
 local r
 if last or link or linked or since == "wikidata" then
 local item = Failsafe.item
 since = false
 if type( item ) == "number" and item > 0 then
 local suited = string.format( "Q%d", item )
 if link then
 r = suited
 else
 local entity = mw.wikibase.getEntity( suited )
 if type( entity ) == "table" then
 local seek = Failsafe.serialProperty or "P348"
 local vsn = entity:formatPropertyValues( seek )
 if type( vsn ) == "table" and
 type( vsn.value ) == "string" and
 vsn.value ~= "" then
 if last and vsn.value == Failsafe.serial then
 r = false
 elseif linked then
 if mw.title.getCurrentTitle().prefixedText
 == mw.wikibase.getSitelink( suited ) then
 r = false
 else
 r = suited
 end
 else
 r = vsn.value
 end
 end
 end
 end
 elseif link then
 r = false
 end
 end
 if type( r ) == "nil" then
 if not since or since <= Failsafe.serial then
 r = Failsafe.serial
 else
 r = false
 end
 end
 return r
 end -- Failsafe.failsafe()



 local Template = function ( frame, action )
 -- Retrieve library result for template access
 -- Precondition:
 -- frame -- object
 -- action -- string; function name
 -- Postcondition:
 -- Returns appropriate string, or error message (development)
 local lucky, r = pcall( URIutil[ action ],
 frame.args[ 1 ] or "",
 frame.args[ 2 ],
 faculty( frame.args.link, true ),
 faculty( frame.args.nbsp, true ),
 frame.args.cat,
 frame.args.fragment );
 if lucky then
 if r then
 r = tostring( r );
 else
 r = "";
 end
 else
 r = fault( r );
 end
 return r;
 end -- Template()



 -- Provide template access and expose URIutil table to require()

 local p = {};

 function p.coreISSN( frame )
 return Template( frame, "coreISSN" );
 end
 function p.formatISBN( frame )
 return Template( frame, "formatISBN" );
 end
 function p.formatISSN( frame )
 return Template( frame, "formatISSN" );
 end
 function p.formatLCCN( frame )
 return Template( frame, "formatLCCN" );
 end
 function p.isDNBvalid( frame )
 return Template( frame, "isDNBvalid" );
 end
 function p.isDOI( frame )
 return Template( frame, "isDOI" );
 end
 function p.isEscValid( frame )
 return Template( frame, "isEscValid" );
 end
 function p.isGTINvalid( frame )
 return Template( frame, "isGTINvalid" );
 end
 function p.isHandle( frame )
 return Template( frame, "isHandle" );
 end
 function p.isISBN( frame )
 return Template( frame, "isISBN" );
 end
 function p.isISBNvalid( frame )
 return Template( frame, "isISBNvalid" );
 end
 function p.isISSNvalid( frame )
 return Template( frame, "isISSNvalid" );
 end
 function p.isLCCN( frame )
 return Template( frame, "isLCCN" );
 end
 function p.linkDNBopac( frame )
 return Template( frame, "linkDNBopac" );
 end
 function p.linkDOI( frame )
 return Template( frame, "linkDOI" );
 end
 function p.linkHandle( frame )
 return Template( frame, "linkHandle" );
 end
 function p.linkISBN( frame )
 return Template( frame, "linkISBN" );
 end
 function p.linkISSN( frame )
 return Template( frame, "linkISSN" );
 end
 function p.linkLCCN( frame )
 return Template( frame, "linkLCCN" );
 end
 function p.linkPMID( frame )
 return Template( frame, "linkPMID" );
 end
 function p.linkURN( frame )
 return Template( frame, "linkURN" );
 end
 function p.mayDOI( frame )
 return Template( frame, "mayDOI" );
 end
 function p.mayHandle( frame )
 return Template( frame, "mayHandle" );
 end
 function p.mayISBN( frame )
 return Template( frame, "mayISBN" );
 end
 function p.mayISSN( frame )
 return Template( frame, "mayISSN" );
 end
 function p.mayLCCN( frame )
 return Template( frame, "mayLCCN" );
 end
 function p.mayURI( frame )
 return Template( frame, "mayURI" );
 end
 function p.mayURN( frame )
 return Template( frame, "mayURN" );
 end
 function p.plainISBN( frame )
 return Template( frame, "plainISBN" );
 end
 function p.targetISSN( frame )
 return Template( frame, "targetISSN" );
 end
 function p.uriDOI( frame )
 return Template( frame, "uriDOI" );
 end
 function p.uriHandle( frame )
 return Template( frame, "uriHandle" );
 end
 function p.uriURN( frame )
 return Template( frame, "uriURN" );
 end
 p.failsafe = function ( frame )
 local s = type( frame );
 local since;
 if s == "table" then
 since = frame.args[ 1 ];
 elseif s == "string" then
 since = frame;
 end
 if since then
 since = mw.text.trim( since );
 if since == "" then
 since = false;
 end
 end
 return Failsafe.failsafe( since ) or "";
 end -- p.failsafe()
 function p.URIutil( arg )
 local r;
 if arg then
 r = "";
 else
 r = URIutil;
 end
 return r;
 end

 setmetatable( p, { __call = function ( func, ... )
 setmetatable( p, nil )
 return Failsafe
 end } )

 return p;