require('strict') local getArgs = require('মডিউল:Arguments').getArgs local catPair = require('মডিউল:বিষয়শ্রেণী যুগল')._pair  local p = {}  -- Ordered list of eons, era, periods, etc. The code will search through -- these lists for a match, then return an appropriate link to the timespans -- adjacent to those matches  p.eon = {'Hadean', 'Archean', 'Proterozoic', 'Phanerozoic'}  p.era = {'Eoarchean', 'Paleoarchean', 'Mesoarchean', 'Neoarchean', 	'Paleoproterozoic', 'Mesoproterozoic', 'Neoproterozoic', 	'Paleozoic', 'Mesozoic', 'Cenozoic'}  p.period = {'Siderian', 'Rhyacian', 'Orosirian', 'Statherian', 	'Calymmian', 'Ectasian', 'Stenian', 	'Tonian', 'Cryogenian', 'Ediacaran', 	'Cambrian', 'Ordovician', 'Silurian', 'Devonian', 'Carboniferous', 'Permian', 	'Triassic', 'Jurassic', 'Cretaceous', 'Paleogene', 'Neogene', 'Quaternary'}  p.epoch = {'Terreneuvian', 'Cambrian Series 2', 'Miaolingian', 'Furongian', 	'Early Ordovician', 'Middle Ordovician', 'Late Ordovician', 	{base='Llandovery', dab='epoch'}, {base='Wenlock', dab='epoch'}, 	{base='Ludlow', dab='epoch'}, {base='Pridoli', dab='epoch'}, 	'Early Devonian', 'Middle Devonian', 'Late Devonian', 	{base='Mississippian', dab='(geology)'}, {base='Pennsylvanian',dab='(geology)'}, 	'Cisuralian', 'Guadalupian', 'Lopingian', 	'Early Triassic', 'Middle Triassic', 'Late Triassic', 	'Early Jurassic', 'Middle Jurassic', 'Late Jurassic', 	'Early Cretaceous', 'Late Cretaceous', 	'Paleocene', 'Eocene', 'Oligocene', 	'Miocene', 'Pliocene', 'Pleistocene', 'Holocene'}  p.series = {'Furongian', 	'Lower Ordovician', 'Middle Ordovician', 'Upper Ordovician', 	'Llandovery', 'Wenlock', 'Ludlow', 'Pridoli', 	'Lower Devonian', 'Middle Devonian', 'Upper Devonian', 	'Lower Carboniferous', 'Upper Carboniferous', 	'Cisuralian', 'Guadalupian', 'Lopingian', 	'Lower Triassic', 'Middle Triassic', 'Upper Triassic', 	'Lower Jurassic', 'Middle Jurassic', 'Upper Jurassic', 	'Lower Cretaceous', 'Upper Cretaceous','Paleocene'}  p.age = {'Fortunian', 'Cambrian Stage 2', 'Cambrian Stage 3', 'Cambrian Stage 4', 	'Wuliuan', 'Drumian', 'Guzhangian', 'Paibian', 'Jiangshanian', 'Cambrian Stage 10', 	'Tremadocian', 'Floian', 'Dapingian', 'Darriwilian', 'Sandbian', 'Katian', 'Hirnantian', 	'Rhuddanian', 'Aeronian', 'Telychian', 'Sheinwoodian', 'Homerian', 'Gorstian', 'Ludfordian', 	'Lochkovian', 'Pragian', 'Emsian', 'Eifelian', 'Givetian', 'Frasnian', 'Famennian', 	'Tournaisian', 'Viséan', 'Serpukhovian', 'Bashkirian', {base='Moscovian', dab='(Carboniferous)'}, 'Kasimovian', 'Gzhelian', 	'Asselian', 'Sakmarian', 'Artinskian', 'Kungurian', 'Roadian', 'Wordian', 'Capitanian', 'Wuchiapingian', 'Changhsingian', 	'Induan', 'Olenekian', 'Anisian', 'Ladinian', 'Carnian', 'Norian', 'Rhaetian', 	'Hettangian', 'Sinemurian', 'Pliensbachian', 'Toarcian', 'Aalenian', 'Bajocian', 	'Bathonian', 'Callovian', {base='Oxfordian', dab='(stage)'}, 'Kimmeridgian', 'Tithonian', 	'Berriasian','Valanginian','Hauterivian','Barremian','Aptian','Albian', 	'Cenomanian','Turonian','Coniacian','Santonian','Campanian','Maastrichtian', 	'Danian','Selandian','Thanetian','Ypresian','Lutetian','Bartonian','Priabonian','Rupelian','Chattian', 	{base='Aquitanian', dab='(stage)'},'Burdigalian','Langhian','Serravallian','Tortonian','Messinian','Zanclean','Piacenzian', 	'Gelasian',{base='Calabrian', dab='(stage)'},'Calabrian','Late Pleistocene','Greenlandian','Northgrippian','Meghalayan'}  -- Determine whether a query string matches a stored timespan string -- Arguments: --   s: query string --   sub: standard name of timespan -- Returns: --   false if there is no match --   prefix and suffix of match, otherwise local function matches(s, sub) 	local sLen = mw.ustring.len(s) 	local subLen = mw.ustring.len(sub) 	if subLen > sLen then 		return false 	end 	local lowerS = mw.ustring.lower(s) 	local lowerSub = mw.ustring.lower(sub) 	local startOffset, endOffset = mw.ustring.find(lowerS,lowerSub,1,true) 	if not startOffset then 		return false 	end 	return (mw.ustring.sub(s,1,startOffset-1) or ""), (mw.ustring.sub(s,endOffset+1) or "") end  -- Create list of strings to search corresponding to a standard timespan -- Some timespans are disambiguated: first search for the dabbed title, then -- the base title. Otherwise just search for the standard timespan string -- Argument: --   span = value in timespan lists (above) -- Returns: --   list of strings to search in query string local function searchStringList(span) 	if type(span) == "table" then 		return {span.base.." "..span.dab, span.base} 	end 	return {span} end  -- When an adjacent time span is found, this function returns the -- corresponding basename for the page. -- Arguments: --   span: adjacent entry from table, above --   prefix: prefix of query string before match --   suffix: remainder of original query string beyond match -- Returns: --   page title -- -- If the adjacent time span is dabbed, then return the dab if the suffix -- is empty. If the suffix is non-empty (e.g., "life"), append it to the base -- name of the span (e.g., "Oxfordian") --> "Oxfordian life" local function matchedString(span, prefix, suffix) 	if type(span) == "table" then 		if prefix == "" and suffix == "" then 			return span.base.." "..span.dab 		end 		return prefix..span.base..suffix 	end 	return prefix..span..suffix end  -- Function to find the page titles of time spans adjacent to a query string -- Arguments: --   s: query string to search for local function find(s) 	-- Search from most-specific to least, to catch "Cambrian Series 2" before "Cambrian" 	for _, list in ipairs({p.age, p.epoch, p.series, p.period, p.era, p.eon}) do 		local listLen = #list 		for i, span in ipairs(list) do 			-- Each timespan might have more than one search string 			for _, searchString in ipairs(searchStringList(span)) do 				local prefix, suffix = matches(s, searchString) 				if suffix then 					local prevSpan = i > 1 and matchedString(list[i-1], prefix, suffix) 					local nextSpan = i < listLen and matchedString(list[i+1], prefix, suffix) 					-- return first match found 					return {prev=prevSpan, next=nextSpan} 				end 			end 		end 	end 	return nil		 end  -- Lua entry point to generate see also hatnote for geological time spans adjanct in time -- Arguments: --   args[1]: name of page to generate adjacency (current page if None) -- Returns: --   See also previous and next, formatted as a hatnote function p._seeAlso(args) 	local title = args[1] and mw.title.new(args[1]) or mw.title.getCurrentTitle() 	local basetext = title.baseText 	local namespace = title.namespace 	local adjacent = find(basetext) 	if not adjacent then 		local warning = require('Module:If preview')._warning 		local warn = warning({"Cannot find geological time frame in "..basetext}) 		if mw.title.getCurrentTitle().nsText ~= "Template" then 			warn = warn.."Category:Missing geological time frame" 		end 		return warn 	end 	local prevTitle = adjacent.prev and mw.title.new(adjacent.prev, namespace) 	local nextTitle = adjacent.next and mw.title.new(adjacent.next, namespace) 	return catPair(prevTitle, nextTitle) end  -- Template entry point function p.seeAlso(frame) 	local args = getArgs(frame) 	return p._seeAlso(args) end  return p