モジュール:Multilingual

local Multilingual = { suite   = "Multilingual",
serial  = "2020-12-10",
item    = 47541920,
globals = { ISO15924 = 71584769,
WLink    = 19363224 }
}
--=
Utilities for multilingual texts and ISO 639 (BCP47) issues etc.- fair()- fallback()- findCode()- fix()- format()- getBase()- getLang()- getName()- i18n()- int()- isLang()- isLangWiki()- isMinusculable()- isRTL()- message()- sitelink()- tabData()- userLang()- userLangCode()- wikibase()- failsafe()
loadData: Multilingual/config Multilingual/names
**
local Failsafe   = Multilingual
local GlobalMod  = Multilingual
local GlobalData = Multilingual
local User       = { sniffer = "showpreview" }
Multilingual.globals.Multilingual = Multilingual.item
Multilingual.exotic = { simple = true,
no     = true }
Multilingual.prefer = { cs = true,
de = true,
en = true,
es = true,
fr = true,
it = true,
nl = true,
pt = true,
ru = true,
sv = true }
local foreignModule = function ( access, advanced, append, alt, alert )
-- Fetch global module
-- Precondition:
--     access    -- string, with name of base module
--     advanced  -- true, for require(); else mw.loadData()
--     append    -- string, with subpage part, if any; or false
--     alt       -- number, of wikidata item of root; or false
--     alert     -- true, for throwing error on data problem
-- Postcondition:
--     Returns whatever, probably table
-- 2020-01-01
local storage = access
local finer = function ()
if append then
storage = string.format( "%s/%s",
storage,
append )
end
end
local fun, lucky, r, suited
if advanced then
fun = require
else
fun = mw.loadData
end
GlobalMod.globalModules = GlobalMod.globalModules or { }
suited = GlobalMod.globalModules access 
if not suited then
finer()
lucky, r = pcall( fun,  "Module:" .. storage )
end
if not lucky then
if not suited  and
type( alt ) == "number"  and
alt > 0 then
suited = string.format( "Q%d", alt )
suited = mw.wikibase.getSitelink( suited )
GlobalMod.globalModules access  = suited or true
end
if type( suited ) == "string" then
storage = suited
finer()
lucky, r = pcall( fun, storage )
end
if not lucky and alert then
error( "Missing or invalid page: " .. storage )
end
end
return r
end -- foreignModule()
local fetchData = function ( access )
-- Retrieve translated keyword from commons:Data:****.tab
-- Precondition:
--     access  -- string, with page identification on Commons
--     Returns table, with data, or string, with error message
-- 2019-12-05
local storage = access
local r
if type( storage ) == "string" then
local s
storage = mw.text.trim( storage )
s = storage:lower()
if s:sub( 1, 2 ) == "c:" then
storage = mw.text.trim( storage:sub( 3 ) )
s       = storage:lower()
elseif s:sub( 1, 8 ) == "commons:" then
storage = mw.text.trim( storage:sub( 9 ) )
s       = storage:lower()
end
if s:sub( 1, 5 ) == "data:" then
storage = mw.text.trim( storage:sub( 6 ) )
s       = storage:lower()
end
if s == ""  or  s == ".tab" then
storage = false
elseif s:sub( -4 ) == ".tab" then
storage = storage:sub( 1, -5 ) .. ".tab"
else
storage = storage .. ".tab"
end
end
if type( storage ) == "string" then
local data
if type( GlobalData.TabDATA ) ~= "table" then
GlobalData.TabDATA = { }
end
data = GlobalData.TabDATA storage 
if data then
r = data
else
local lucky
lucky, data = pcall( mw.ext.data.get, storage, "_" )
if type( data ) == "table" then
data = data.data
if type( data ) == "table" then
GlobalData.TabDATA storage  = data
else
r = string.format( "%s %s%s",
"INVALID Data:*.tab",
"commons:Data:",
storage )
end
else
r = "BAD PAGE Data:*.tab – commons:" .. storage
end
if r then
GlobalData.TabDATA storage  = r
data = false
else
r = data
end
end
else
r = "BAD PAGE commons:Data:*.tab"
end
return r
end -- fetchData()
local favorites = function ()
-- Provide fallback codes
-- Postcondition:
--     Returns table with sequence of preferred languages
--     * ahead elements
--     * user (not yet accessible)
--     * page content language (not yet accessible)
--     * page name subpage
--     * project
--     * en
local r = Multilingual.polyglott
if not r then
local self = mw.language.getContentLanguage():getCode():lower()
local sub  = mw.title.getCurrentTitle().subpageText
local f    = function ( add )
local s = add
for i = 1, #r do
if r i  == s then
s = false
break -- for i
end
end -- for i
if s then
table.insert( r, s )
end
end
r = { }
if sub:find( "/", 2, true ) then
sub = sub:match( "/(%l%l%l?)$" )
if sub then
table.insert( r, sub )
end
elseif sub:find( "^%l%l%l?%-?%a?%a?%a?%a?$" )  and
mw.language.isSupportedLanguage( sub ) then
table.insert( r, sub )
end
f( self )
f( "en" )
Multilingual.polyglott = r
end
return r
end -- favorites()
local feasible = function ( ask, accept )
-- Is ask to be supported by application?
-- Precondition:
--     ask     -- lowercase code
--     accept  -- sequence table, with offered lowercase codes
-- Postcondition:
--     nil, or true
local r
for i = 1, #accept do
if accept i  == ask then
r = true
break -- for i
end
end -- for i
return r
end -- feasible()
local fetch = function ( access, append )
-- Attach config or library module
-- Precondition:
--     access  -- module title
--     append  -- string, with subpage part of this; or false
-- Postcondition:
--     Returns:  table, with library, or false
local got, sign
if append then
sign = string.format( "%s/%s", access, append )
else
sign = access
end
if type( Multilingual.ext ) ~= "table" then
Multilingual.ext = { }
end
got = Multilingual.ext sign 
if not got  and  got ~= false then
local global = Multilingual.globals access 
local lib    = ( not append  or  append == "config" )
got = foreignModule( access, lib, append, global )
if type( got ) == "table" then
if lib then
local startup = got access 
if type( startup ) == "function" then
got = startup()
end
end
else
got = false
end
Multilingual.ext sign  = got
end
return got
end -- fetch()
local fetchISO639 = function ( access )
-- Retrieve table from commons:Data:ISO639/***.tab
-- Precondition:
--     access  -- string, with subpage identification
-- Postcondition:
--     Returns table, with data, even empty
local r
if type( Multilingual.iso639 ) ~= "table" then
Multilingual.iso639 = { }
end
r = Multilingual.iso639 access 
if type( r ) == "nil" then
local raw = fetchData( "ISO639/" .. access )
if type( raw ) == "table" then
local t
r = { }
for i = 1, #raw do
t = raw i 
if type( t ) == "table"  and
type( t 1  ) == "string"  and
type( t 2  ) == "string" then
r t 1   =  t 2 
else
break -- for i
end
end -- for i
else
r = false
end
Multilingual.iso639 access  = r
end
return r or { }
end -- fetchISO639()
local fill = function ( access, alien, frame )
-- Expand language name template
-- Precondition:
--     access  -- string, with language code
--     alien   -- language code for which to be generated
--     frame   -- frame, if available
-- Postcondition:
--     Returns string
local template = Multilingual.tmplLang
local r
if type( template ) ~= "table" then
local cnf = fetch( "Multilingual", "config" )
if cnf then
template = cnf.tmplLang
end
end
if type( template ) == "table" then
local source = template.title
local f, lucky, s
Multilingual.tmplLang = template
if type( source ) ~= "string"  and
type( template.namePat ) == "string"  and
template.namePat:find( "%s", 1, true ) then
source = string.format( template.namePat, access )
end
if type( source ) == "string" then
if not Multilingual.frame then
if frame then
Multilingual.frame = frame
else
Multilingual.frame = mw.getCurrentFrame()
end
end
f = function ( a )
return Multilingual.frame:expandTemplate{ title = a }
end
lucky, s = pcall( f, source )
if lucky then
r = s
end
end
end
return r
end -- fill()
local find = function ( ask, alien )
-- Derive language code from name
-- Precondition:
--     ask    -- language name, downcased
--     alien  -- language code of ask
-- Postcondition:
--     nil, or string
local codes = mw.language.fetchLanguageNames( alien, "all" )
local r
for k, v in pairs( codes ) do
if mw.ustring.lower( v ) == ask then
r = k
break -- for k, v
end
end -- for k, v
if not r then
r = Multilingual.fair( ask )
end
return r
end -- find()
local fold = function ( frame )
-- Merge template and #invoke arglist
-- Precondition:
--     frame   -- template frame
-- Postcondition:
--     table, with combined arglist
local r = { }
local f = function ( apply )
if type( apply ) == "table"  and
type( apply.args ) == "table" then
for k, v in pairs( apply.args ) do
v = mw.text.trim( v )
if v ~= "" then
r tostring( k )  = v
end
end -- for k, v
end
end -- f()
f( frame:getParent() )
f( frame )
return r
end -- fold()
User.favorize = function ( accept, frame )
-- Guess user language
-- Precondition:
--     accept  -- sequence table, with offered ISO 639 etc. codes
--     frame   -- frame, if available
-- Postcondition:
--     Returns string with best code, or nil
if not ( User.self or User.langs ) then
if not User.trials then
User.tell = mw.message.new( User.sniffer )
if User.tell:exists() then
User.trials = { }
if not Multilingual.frame then
if frame then
Multilingual.frame = frame
else
Multilingual.frame = mw.getCurrentFrame()
end
end
User.sin = Multilingual.frame:callParserFunction( "int",
User.sniffer )
else
User.langs = true
end
end
if User.sin then
local order  = { }
local post   = { }
local three  = { }
local unfold = { }
local s, sin
for i = 1, #accept do
s = accept i 
if not User.trials s  then
if #s > 2 then
if s:find( "-", 3, true ) then
table.insert( unfold, s )
else
table.insert( three, s )
end
else
if Multilingual.prefer s  then
table.insert( order, s )
else
table.insert( post, s )
end
end
end
end -- for i
for i = 1, #post do
table.insert( order, post i  )
end -- for i
for i = 1, #three do
table.insert( order, three i  )
end -- for i
for i = 1, #unfold do
table.insert( order, unfold i  )
end -- for i
for i = 1, #order do
s = order i 
sin = User.tell:inLanguage( s ):plain()
if sin == User.sin then
User.self = s
break -- for i
else
User.trials s  = true
end
end -- for i
end
end
return User.self
end -- User.favorize()
Multilingual.fair = function ( ask )
-- Format language specification according to RFC 5646 etc.
-- Precondition:
--     ask  -- string or table, as created by .getLang()
-- Postcondition:
--     Returns string, or false
local s = type( ask )
local q, r
if s == "table" then
q = ask
elseif s == "string" then
q = Multilingual.getLang( ask )
end
if q  and
q.legal  and
mw.language.isKnownLanguageTag( q.base ) then
r = q.base
if q.n > 1 then
local order = { "extlang",
"script",
"region",
"other",
"extension" }
for i = 1, #order do
s = q order i  
if s then
r =  string.format( "%s-%s", r, s )
end
end -- for i
end
end
return r or false
end -- Multilingual.fair()
Multilingual.fallback = function ( able, another )
-- Is another language suitable as replacement?
-- Precondition:
--     able     -- language version specifier to be supported
--     another  -- language specifier of a possible replacement,
--                 or not to retrieve a fallback table
-- Postcondition:
--     Returns boolean, or table with fallback codes
local r
if type( able ) == "string"  and  #able > 0 then
if type( another ) == "string"  and  #another > 0 then
if able == another then
r = true
else
local s = Multilingual.getBase( able )
if s == another then
r = true
else
local others = mw.language.getFallbacksFor( s )
r = feasible( another, others )
end
end
else
local s = Multilingual.getBase( able )
if s then
r = mw.language.getFallbacksFor( s )
if r 1  == "en" then
local d = fetchISO639( "fallback" )
if type( d ) == "table"  and
type( d s  ) == "string" then
r = mw.text.split( d s , "|" )
table.insert( r, "en" )
end
end
end
end
end
return r or false
end -- Multilingual.fallback()
Multilingual.findCode = function ( ask )
-- Retrieve code of local (current project or English) language name
-- Precondition:
--     ask  -- string, with presumable language name
--             A code itself will be identified, too.
-- Postcondition:
--     Returns string, or false
local seek = mw.text.trim( ask )
local r = false
if #seek > 1 then
if seek:find( "", 1, true ) then
local wlink = fetch( "WLink" )
if wlink  and
type( wlink.getPlain ) == "function" then
seek = wlink.getPlain( seek )
end
end
seek = mw.ustring.lower( seek )
if Multilingual.isLang( seek ) then
r = Multilingual.fair( seek )
else
local collection = favorites()
for i = 1, #collection do
r = find( seek, collection i  )
if r then
break -- for i
end
end -- for i
end
end
return r
end -- Multilingual.findCode()
Multilingual.fix = function ( attempt )
-- Fix frequently mistaken language code
-- Precondition:
--     attempt  -- string, with presumable language code
-- Postcondition:
--     Returns string with correction, or false if no problem known
local r = fetchISO639( "correction" ) attempt:lower() 
return r or false
end -- Multilingual.fix()
Multilingual.format = function ( apply, alien, alter, active, alert,
frame, assembly, adjacent, ahead )
-- Format one or more languages
-- Precondition:
--     apply     -- string with language list or item
--     alien     -- language of the answer
--                  -- nil, false, "*": native
--                  -- "!": current project
--                  -- "#": code, downcased, space separated
--                  -- "-": code, mixcase, space separated
--                  -- any valid code
--     alter     -- capitalize, if "c"; downcase all, if "d"
--                  capitalize first item only, if "f"
--                  downcase every first word only, if "m"
--     active    -- link items, if true
--     alert     -- string with category title in case of error
--     frame     -- if available
--     assembly  -- string with split pattern, if list expected
--     adjacent  -- string with list separator, else assembly
--     ahead     -- string to prepend first element, if any
-- Postcondition:
--     Returns string, or false if apply empty
local r = false
if apply then
local slang
if assembly then
local bucket = mw.text.split( apply, assembly )
local shift = alter
local separator
if adjacent then
separator = adjacent
elseif alien == "#"  or  alien == "-" then
separator = " "
else
separator = assembly
end
for k, v in pairs( bucket ) do
slang = Multilingual.format( v, alien, shift, active,
alert )
if slang then
if r then
r = string.format( "%s%s%s",
r, separator, slang )
else
r = slang
if shift == "f" then
shift = "d"
end
end
end
end -- for k, v
if r and ahead then
r = ahead .. r
end
else
local single = mw.text.trim( apply )
if single == "" then
r = false
else
local lapsus, slot
slang = Multilingual.findCode( single )
if slang then
if alien == "-" then
r = slang
elseif alien == "#" then
r = slang:lower()
else
r = Multilingual.getName( slang, alien )
if active then
slot = fill( slang, false, frame )
if slot then
local wlink = fetch( "WLink" )
if wlink  and
type( wlink.getTarget )

**"function" then
slot = wlink.getTarget( slot )
end
else
lapsus = alert
end
end
end
else
r = single
if active then
local title = mw.title.makeTitle( 0, single )
if title.exists then
slot = single
end
end
lapsus = alert
end
if not r then
r = single
elseif alter == "c" or alter == "f" then
r = mw.ustring.upper( mw.ustring.sub( r, 1, 1 ) )
.. mw.ustring.sub( r, 2 )
elseif alter == "d" then
if Multilingual.isMinusculable( slang, r ) then
r = mw.ustring.lower( r )
end
elseif alter == "m" then
if Multilingual.isMinusculable( slang, r ) then
r = mw.ustring.lower( mw.ustring.sub( r, 1, 1 ) )
.. mw.ustring.sub( r, 2 )
end
end
if slot then
if r == slot then
r = string.format( "%s", r )
else
r = string.format( "%s", slot, r )
end
end
if lapsus and alert then
r = string.format( "%s", r, alert )
end
end
end
end
return r
end -- Multilingual.format()
Multilingual.getBase = function ( ask )
-- Retrieve base language from possibly combined ISO language code
-- Precondition:
--     ask  -- language code
-- Postcondition:
--     Returns string, or false
local r
if ask then
local slang = ask:match( "^%s*(%a%a%a?)-?%a*%s*$" )
if slang then
r = slang:lower()
else
r = false
end
else
r = false
end
return r
end -- Multilingual.getBase()
Multilingual.getLang = function ( ask )
-- Retrieve components of a RFC 5646 language code
-- Precondition:
--     ask  -- language code with subtags
-- Postcondition:
--     Returns table with formatted subtags
--             .base
--             .region
--             .script
--             .suggest
--             .year
--             .extension
--             .other
--             .n
local tags = mw.text.split( ask, "-" )
local s    = tags 1 
local r
if s:match( "^%a%a%a?$" ) then
r = { base  = s:lower(),
legal = true,
n     = #tags }
for i = 2, r.n do
s = tags i 
if #s == 2 then
if r.region  or  not s:match( "%a%a" ) then
r.legal = false
else
r.region = s:upper()
end
elseif #s == 4 then
if s:match( "%a%a%a%a" ) then
r.legal = ( not r.script )
r.script = s:sub( 1, 1 ):upper() ..
s:sub( 2 ):lower()
elseif s:match( "20%d%d" )  or
s:match( "1%d%d%d" ) then
r.legal = ( not r.year )
r.year = s
else
r.legal = false
end
elseif #s == 3 then
if r.extlang  or  not s:match( "%a%a%a" ) then
r.legal = false
else
r.extlang = s:lower()
end
elseif #s == 1 then
s = s:lower()
if s:match( "tux" ) then
r.extension = s
for k = i + 1, r.n do
s = tags k 
if s:match( "^%w+$" ) then
r.extension = string.format( "%s-%s",
r.extension, s )
else
r.legal = false
end
end -- for k
else
r.legal = false
end
break -- for i
else
r.legal = ( not r.other )  and
s:match( "%a%a%a" )
r.other = s:lower()
end
if not r.legal then
break -- for i
end
end -- for i
if r.legal then
r.suggest = Multilingual.fix( r.base )
if r.suggest then
r.legal = false
end
end
else
r = { legal = false }
end
if not r.legal then
local cnf = fetch( "Multilingual", "config" )
if cnf  and  type( cnf.scream ) == "string" then
r.scream = cnf.scream
end
end
return r
end -- Multilingual.getLang()
Multilingual.getName = function ( ask, alien )
-- Which name is assigned to this language code?
-- Precondition:
--     ask    -- language code
--     alien  -- language of the answer
--               -- nil, false, "*": native
--               -- "!": current project
--               -- any valid code
-- Postcondition:
--     Returns string, or false
local r
if ask then
local slang   = alien
local tLang
if slang then
if slang == "*" then
slang = Multilingual.fair( ask )
elseif slang == "!" then
slang = favorites() 1 
else
slang = Multilingual.fair( slang )
end
else
slang = Multilingual.fair( ask )
end
if not slang then
slang = ask or "?????"
end
slang = slang:lower()
tLang = fetch( "Multilingual", "names" )
if tLang then
tLang = tLang slang 
if tLang then
r = tLang ask 
end
end
if not r then
if not Multilingual.ext.tMW then
Multilingual.ext.tMW = { }
end
tLang = Multilingual.ext.tMW slang 
if tLang == nil then
tLang = mw.language.fetchLanguageNames( slang )
if tLang then
Multilingual.ext.tMW slang  = tLang
else
Multilingual.ext.tMW slang  = false
end
end
if tLang then
r = tLang ask 
end
end
if not r then
r = mw.language.fetchLanguageName( ask:lower(), slang )
if r == "" then
r = false
end
end
else
r = false
end
return r
end -- Multilingual.getName()
Multilingual.i18n = function ( available, alt, frame )
-- Select translatable message
-- Precondition:
--     available  -- table, with mapping language code ./. text
--     alt        -- string|nil|false, with fallback text
--     frame      -- frame, if available
--     Returns
--         1. string|nil|false, with selected message
--         2. string|nil|false, with language code
local r1, r2
if type( available ) == "table" then
local codes = { }
local trsl  = { }
local slang
for k, v in pairs( available ) do
if type( k ) == "string"  and
type( v ) == "string" then
slang = mw.text.trim( k:lower() )
table.insert( codes, slang )
trsl slang  = v
end
end -- for k, v
slang = Multilingual.userLang( codes, frame )
if slang  and  trsl slang  then
r1 = mw.text.trim( trsl slang  )
if r1 == "" then
r1 = false
else
r2 = slang
end
end
end
if not r1  and  type( alt ) == "string" then
r1 = mw.text.trim( alt )
if r1 == "" then
r1 = false
end
end
return r1, r2
end -- Multilingual.i18n()
Multilingual.int = function ( access, alien, apply )
-- Translated system message
-- Precondition:
--     access  -- message ID
--     alien   -- language code
--     apply   -- nil, or sequence table with parameters $1, $2, ...
-- Postcondition:
--     Returns string, or false
local o = mw.message.new( access )
local r
if o:exists() then
if type( alien ) == "string" then
o:inLanguage( alien:lower() )
end
if type( apply ) == "table" then
o:params( apply )
end
r = o:plain()
end
return r or false
end -- Multilingual.int()
Multilingual.isLang = function ( ask, additional )
-- Could this be an ISO language code?
-- Precondition:
--     ask         -- language code
--     additional  -- true, if Wiki codes like "simple" permitted
-- Postcondition:
--     Returns boolean
local r, s
if additional then
s = ask
else
s = Multilingual.getBase( ask )
end
if s then
r = mw.language.isKnownLanguageTag( s )
if r then
r = not Multilingual.fix( s )
elseif additional then
r = Multilingual.exotic s  or false
end
else
r = false
end
return r
end -- Multilingual.isLang()
Multilingual.isLangWiki = function ( ask )
-- Could this be a Wiki language version?
-- Precondition:
--     ask  -- language version specifier
-- Postcondition:
--     Returns boolean
local r
local s = Multilingual.getBase( ask )
if s then
r = mw.language.isSupportedLanguage( s )  or
Multilingual.exotic ask 
else
r = false
end
return r
end -- Multilingual.isLangWiki()
Multilingual.isMinusculable = function ( ask, assigned )
-- Could this language name become downcased?
-- Precondition:
--     ask       -- language code, or nil
--     assigned  -- language name, or nil
-- Postcondition:
--     Returns boolean
local r = true
if ask then
local cnf = fetch( "Multilingual", "config" )
if cnf then
local s = string.format( " %s ", ask:lower() )
if type( cnf.stopMinusculization ) == "string"
and  cnf.stopMinusculization:find( s, 1, true ) then
r = false
end
if r  and  assigned
and  type( cnf.seekMinusculization ) == "string"
and  cnf.seekMinusculization:find( s, 1, true )
and  type( cnf.scanMinusculization ) == "string" then
local scan = assigned:gsub( "%(%)", " " ) .. " "
if not scan:find( cnf.scanMinusculization ) then
r = false
end
end
end
end
return r
end -- Multilingual.isMinusculable()
Multilingual.isRTL = function ( ask )
-- Check whether language is written right-to-left
-- Precondition:
--     ask  -- string, with language (or script) code
-- Returns true, if right-to-left
local r
Multilingual.rtl = Multilingual.rtl or { }
r = Multilingual.rtl ask 
if type( r ) ~= "boolean" then
local bib = fetch( "ISO15924" )
if type( bib ) == "table"  and
type( bib.isRTL ) == "function" then
r = bib.isRTL( ask )
else
r = mw.language.new( ask ):isRTL()
end
Multilingual.rtl ask  = r
end
return r
end -- Multilingual.isRTL()
Multilingual.message = function ( arglist, frame )
-- Show text in best match of user language like system message
-- Precondition:
--     arglist  -- template arguments
--     frame    -- frame, if available
-- Postcondition:
--     Returns string with appropriate text
local r
if type( arglist ) == "table" then
local t = { }
local m, p, save
for k, v in pairs( arglist ) do
if type( k ) == "string"  and
type( v ) == "string" then
v = mw.text.trim( v )
if v ~= "" then
if k:match( "^%l%l" ) then
t k  = v
elseif k:match( "^%$%d$" )  and  k ~= "$0" then
p = p or { }
k = tonumber( k:match( "^%$(%d)$" ) )
p k  = v
if not m  or  k > m then
m = k
end
end
end
end
end -- for k, v
if type( arglist "-"  ) == "string" then
save = arglist arglist "-"  
end
r = Multilingual.i18n( t, save, frame )
if p  and  r  and  r:find( "$", 1, true ) then
t = { }
for i = 1, m do
t i  = p i   or  ""
end -- for i
r = mw.message.newRawMessage( r, t ):plain()
end
end
return r  or  ""
end -- Multilingual.message()
Multilingual.sitelink = function ( all, frame )
-- Make link at local or other site with optimal linktext translation
-- Precondition:
--     all    -- string or table or number, item ID or entity
--     frame  -- frame, if available
-- Postcondition:
--     Returns string with any helpful internal link, or plain text
local s = type( all )
local object, r
if s == "table" then
object = all
elseif s == "string" then
object = mw.wikibase.getEntity( all )
elseif s == "number" then
object = mw.wikibase.getEntity( string.format( "Q%d", all ) )
end
if type( object ) == "table" then
local collection = object.sitelinks
local entry
s = false
if type( collection ) == "table" then
Multilingual.site = Multilingual.site  or
mw.wikibase.getGlobalSiteId()
entry = collection Multilingual.site 
if entry then
s = ":" .. entry.title
elseif collection.enwiki then
s = "w:en:" .. collection.enwiki.title
end
end
r = Multilingual.wikibase( object, "labels", frame )
if s then
if s == ":" .. r then
r = string.format( "%s", s )
else
r = string.format( "%s", s, r )
end
end
end
return r  or  ""
end -- Multilingual.sitelink()
Multilingual.tabData = function ( access, at, alt, frame )
-- Retrieve translated keyword from commons:Data:****.tab
-- Precondition:
--     access  -- string, with page identification on Commons
--     at      -- string, with keyword
--     alt     -- string|nil|false, with fallback text
--     frame   -- frame, if available
--     Returns
--         1. string|nil|false, with selected message
--         2. language code, or "error"
local data = fetchData( access )
local r1, r2
if  type( data ) == "table" then
if type( at ) == "string" then
local seek = mw.text.trim( at )
if seek == "" then
r1 = "EMPTY Multilingual.tabData key"
else
local e, poly
for i = 1, #data do
e = data i 
if type( e ) == "table" then
if e 1  == seek then
if type( e 2  ) == "table" then
poly = e 2 
else
r1 = "INVALID Multilingual.tabData bad #"
.. tostring( i )
end
break   -- for i
end
else
break   -- for i
end
end   -- for i
if poly then
data = poly
else
r1 = "UNKNOWN Multilingual.tabData key: " .. seek
end
end
else
r1 = "INVALID Multilingual.tabData key"
end
else
r1 = data
end
if r1 then
r2 = "error"
elseif data then
r1, r2 = Multilingual.i18n( data, alt, frame )
r2 = r2 or "error"
end
return r1, r2
end -- Multilingual.tabData()
Multilingual.userLang = function ( accept, frame )
-- Try to support user language by application
-- Precondition:
--     accept  -- string or table
--                space separated list of available ISO 639 codes
--                Default: project language, or English
--     frame   -- frame, if available
-- Postcondition:
--     Returns string with appropriate code
local s = type( accept )
local codes, r, slang
if s == "string" then
codes = mw.text.split( accept:lower(), "%s+" )
elseif s == "table" then
codes = { }
for i = 1, #accept do
s = accept i 
if type( s ) == "string"  and
s ~= "" then
table.insert( codes, s:lower() )
end
end -- for i
end
slang = User.favorize( codes, frame )
if slang then
if feasible( slang, codes ) then
r = slang
elseif slang:find( "-", 1, true ) then
slang = Multilingual.getBase( slang )
if feasible( slang, codes ) then
r = slang
end
end
if not r then
local others = mw.language.getFallbacksFor( slang )
for i = 1, #others do
slang = others i 
if feasible( slang, codes ) then
r = slang
break -- for i
end
end -- for i
end
end
if not r then
local back = favorites()
for i = 1, #back do
slang = back i 
if feasible( slang, codes ) then
r = slang
break -- for i
end
end -- for i
if not r  and  codes 1  then
r = codes 1 
end
end
return r  or  favorites() 1 
end -- Multilingual.userLang()
Multilingual.userLangCode = function ()
-- Guess a user language code
-- Postcondition:
--     Returns code of current best guess
return User.self  or  favorites() 1 
end -- Multilingual.userLangCode()
Multilingual.wikibase = function ( all, about, attempt, frame )
-- Optimal translation of wikibase component
-- Precondition:
--     all      -- string or table, object ID or entity
--     about    -- boolean, true "descriptions" or false "labels"
--     attempt  -- string or not, code of preferred language
--     frame    -- frame, if available
-- Postcondition:
--     Returns
--         1. string, with selected message
--         2. string, with language code, or not
local s = type( all )
local object, r, r2
if s == "table" then
object = all
elseif s == "string" then
object = mw.wikibase.getEntity( all )
end
if type( object ) == "table" then
if about  and  about ~= "labels" then
s = "descriptions"
else
s = "labels"
end
object = object s 
if type( object ) == "table" then
if object attempt  then
r  = object attempt .value
r2 = attempt
else
local poly
for k, v in pairs( object ) do
poly = poly or { }
poly k  = v.value
end -- for k, v
if poly then
r, r2 = Multilingual.i18n( poly, nil, frame )
end
end
end
end
return r  or  "",   r2
end -- Multilingual.wikibase()
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
-- 2020-08-17
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
end
end
if type( r ) == "nil" then
if not since  or  since  n then
n = i
end
end
end
end -- for k, v
if n > 0 then
local s
params = { }
for i = 1, n do
s = frame.args "$" .. tostring( i )   or  ""
table.insert( params, s )
end -- for i
end
r = Multilingual.int( sysMsg, slang, params )
end
end
return r or ""
end -- p.int
p.isLang = function ( frame )
-- Could this be an ISO language code?
--     1  -- code
local s = mw.text.trim( frame.args 1   or  "" )
local lucky, r = pcall( Multilingual.isLang, s )
return r and "1" or ""
end -- p.isLang
p.isLangWiki = function ( frame )
-- Could this be a Wiki language version?
--     1  -- code
-- Returns non-empty, if possibly language version
local s = mw.text.trim( frame.args 1   or  "" )
local lucky, r = pcall( Multilingual.isLangWiki, s )
return r and "1" or ""
end -- p.isLangWiki
p.isRTL = function ( frame )
-- Check whether language is written right-to-left
--     1  -- string, with language code
-- Returns non-empty, if right-to-left
local s = mw.text.trim( frame.args 1   or  "" )
return Multilingual.isRTL( s ) and "1" or ""
end -- p.isRTL()
p.message = function ( frame )
-- Translation of text element
return Multilingual.message( fold( frame ), frame )
end -- p.message
p.sitelink = function ( frame )
-- Make link at local or other site with optimal linktext translation
--     1  -- item ID
local s = mw.text.trim( frame.args 1   or  "" )
local r
if s:match( "^%d+$") then
r = tonumber( s )
elseif s:match( "^Q%d+$") then
r = s
end
if r then
r = Multilingual.sitelink( r, frame )
end
return r or s
end -- p.sitelink
p.tabData = function ( frame )
-- Retrieve best message text from Commons Data
--     1    -- page identification on Commons
--     2    -- keyword
--     alt  -- fallback text
local suite = frame.args 1 
local seek  = frame.args 2 
local salt  = frame.args.alt
local r     = Multilingual.tabData( suite, seek, salt, frame )
return r
end -- p.tabData
p.userLang = function ( frame )
-- Which language does the current user prefer?
--     1  -- space separated list of available ISO 639 codes
local s = mw.text.trim( frame.args 1   or  "" )
return Multilingual.userLang( s, frame )
end -- p.userLang
p.wikibase = function ( frame )
-- Optimal translation of wikibase component
--     1  -- object ID
--     2  -- 1 for "descriptions", 0 for "labels".
--           or either "descriptions" or "labels"
local r
local s = mw.text.trim( frame.args 1   or  "" )
if s ~= "" then
local s2    = mw.text.trim( frame.args 2   or  "0" )
local slang = mw.text.trim( frame.args.lang  or  "" )
local large = ( s2 ~= ""  and  s2 ~= "0" )
if slang == "" then
slang = false
end
r = Multilingual.wikibase( s, large, slang, frame )
end
return r or ""
end -- p.wikibase
p.failsafe = function ( frame )
-- Versioning interface
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()
p.Multilingual = function ()
return Multilingual
end -- p.Multilingual
return p