local p = {}  local macron = mw.ustring.char(0x304) local breve = mw.ustring.char(0x306) local rough = mw.ustring.char(0x314) local smooth = mw.ustring.char(0x313) local diaeresis = mw.ustring.char(0x308) local acute = mw.ustring.char(0x301) local grave = mw.ustring.char(0x300) local circumflex = mw.ustring.char(0x342) local Latin_circumflex = mw.ustring.char(0x302) local subscript = mw.ustring.char(0x345) local macron_circumflex = macron .. diaeresis .. '?' .. Latin_circumflex  local is_velar = { ['κ'] = true, ['γ'] = true, ['χ'] = true, ['ξ'] = true, }  local UTF8_char = "[%z\1-\127\194-\244][\128-\191]*" local basic_Greek = "[\206-\207][\128-\191]" -- excluding first line of Greek and Coptic block: ͰͱͲͳʹ͵Ͷͷͺͻͼͽ;Ϳ  local info = {}  -- The tables are shared among different characters so that they can be checked -- for equality if needed, and to use less space. local vowel = { vowel = true, diacritic_seat = true } local iota = { vowel = true, diacritic_seat = true, offglide = true } local upsilon = { vowel = true, diacritic_seat = true, offglide = true } -- Technically rho is only a seat for rough or smooth breathing. local rho = { consonant = true, diacritic_seat = true } local consonant = { consonant = true } local diacritic = { diacritic = true } -- Needed for equality comparisons. local breathing = { diacritic = true }  local function add_info(characters, t) 	if type(characters) == "string" then 		for character in string.gmatch(characters, UTF8_char) do 			info[character] = t 		end 	else 		for _, character in ipairs(characters) do 			info[character] = t 		end 	end end  add_info({ macron, breve, 		diaeresis, 		acute, grave, circumflex, 		subscript, 	}, diacritic)  add_info({rough, smooth}, breathing) add_info("ΑΕΗΟΩαεηοω", vowel) add_info("Ιι", iota) add_info("Υυ", upsilon) add_info("ΒΓΔΖΘΚΛΜΝΞΠΡΣΤΦΧΨϜϘϺϷͶϠβγδζθκλμνξπρσςτφχψϝϙϻϸͷϡ", consonant) add_info("Ρρ", rho)  local not_recognized = {} setmetatable(info, { __index = 	function() 		return not_recognized 	end })  local function quote(str) 	return "“" ..  str .. "”" end  local correspondences = { 	-- Vowels 	["α"] = "a", 	["ε"] = "e", 	["η"] = "e" .. macron, 	["ι"] = "i", 	["ο"] = "o", 	["υ"] = "u", 	["ω"] = "o" .. macron,  	-- Consonants 	["β"] = "b", 	["γ"] = "g", 	["δ"] = "d", 	["ζ"] = "z", 	["θ"] = "th", 	["κ"] = "k", 	["λ"] = "l", 	["μ"] = "m", 	["ν"] = "n", 	["ξ"] = "x", 	["π"] = "p", 	["ρ"] = "r", 	["σ"] = "s", 	["ς"] = "s", 	["τ"] = "t", 	["φ"] = "ph", 	["ψ"] = "ps", 	 	-- Archaic letters 	["ϝ"] = "w", 	["ϻ"] = "ś", 	["ϙ"] = "q", 	["ϡ"] = "š", 	["ͷ"] = "v", 	 	-- Diacritics 	[smooth] = , 	[rough] = , -- h is added below in the `transliterate` function. 	[breve] = , }  local ALA_LC = { 	["χ"] = "ch", 	[acute] = , 	[grave] = , 	[circumflex] = , 	[subscript] = , 	[diaeresis] = , 	[macron] = , }  local Wiktionary_transliteration = { 	["χ"] = "kh", 	[circumflex] = Latin_circumflex, 	[subscript] = 'i', }  local function add_index_metamethod(t, index_metamethod) 	local mt = getmetatable(t) 	if not mt then 		mt = {} 		setmetatable(t, mt) 	end 	mt.__index = index_metamethod end  --[=[ 		This breaks a word into meaningful "tokens", which are 		individual letters or diphthongs with their diacritics. 		Used by Module:grc-accent and Module:grc-pronunciation. --]=] local function tokenize(text) 	local tokens, vowel_info, prev_info = {}, {}, {} 	local token_i = 1 	local prev 	for character in string.gmatch(mw.ustring.toNFD(text), UTF8_char) do 		local curr_info = info[character] 		-- Split vowels between tokens if not a diphthong. 		if curr_info.vowel then 			if prev and (not (curr_info.offglide and prev_info.vowel) 					-- υυ → υ, υ 					-- ιυ → ι, υ 					or prev_info.offglide and curr_info == upsilon) then 				token_i = token_i + 1 			end 			tokens[token_i] = (tokens[token_i] or "") .. character 			table.insert(vowel_info, { index = token_i }) 		elseif curr_info.diacritic then 			tokens[token_i] = (tokens[token_i] or "") .. character 			if prev_info.vowel or prev_info.diacritic then 				if character == diaeresis then 					-- Current token is vowel, vowel, possibly other diacritics, 					-- and a diaeresis. 					-- Split the current token into two: 					-- the first letter, then the second letter plus any diacritics. 					local previous_vowel, vowel_with_diaeresis = string.match(tokens[token_i], "^(" .. basic_Greek .. ")(" .. basic_Greek .. ".+)") 					if previous_vowel then 						tokens[token_i], tokens[token_i + 1] = previous_vowel, vowel_with_diaeresis 						token_i = token_i + 1 					end 				end 			elseif prev_info == rho then 				if curr_info ~= breathing then 					return string.format("The character %s cannot have the accent %s on it.", prev, "◌" .. character) 				end 			else 				error("The character " .. quote(prev) .. " cannot have a diacritic on it.") 			end 		elseif curr_info == rho then 			if prev and not (prev_info == breathing and info[string.match(tokens[token_i], "^" .. basic_Greek)] == rho) then 				token_i = token_i + 1 			end 			tokens[token_i] = (tokens[token_i] or "") .. character 		else 			if prev then 				token_i = token_i + 1 			end 			tokens[token_i] = (tokens[token_i] or "") .. character 		end 		prev = character 		prev_info = curr_info 	end 	return tokens end  function p.transliterate(text, system) 	add_index_metamethod(correspondences, system == "ALA-LC" and ALA_LC or Wiktionary_transliteration) 	 	if text == '῾' then 		return 'h' 	end 	 	text = mw.ustring.toNFD(text) 	 	--[[ 		Replace semicolon or Greek question mark with regular question mark, 		except after an ASCII alphanumeric character (to avoid converting 		semicolons in HTML entities). 	--]] 	text = mw.ustring.gsub(text, "([^A-Za-z0-9])[;" .. mw.ustring.char(0x37E) .. "]", "%1?") 	 	-- Handle the middle dot. It is equivalent to semicolon or colon, but semicolon is probably more common. 	text = text:gsub("·", ";") 	 	local tokens = tokenize(text)  	--now read the tokens 	local output = {} 	for i, token in pairs(tokens) do 		-- substitute each character in the token for its transliteration 		local translit = string.gsub(mw.ustring.lower(token), UTF8_char, correspondences) 		 		if token == 'γ' and is_velar[tokens[i + 1]] then 			-- γ before a velar should be <n> 			translit = 'n' 		elseif token == 'ρ' and tokens[i - 1] == 'ρ' then 			-- ρ after ρ should be <rh> 			translit = 'rh' 		elseif system == "Wiktionary" and mw.ustring.find(token, '^[αΑ].*' .. subscript .. '$') then 			-- add macron to ᾳ 			translit = mw.ustring.gsub(translit, '([aA])', '%1' .. macron) 		end 		 		if token:find(rough) then 			if mw.ustring.find(token, '[Ρρ]') then 				translit = translit .. 'h' 			else -- vowel 				translit = 'h' .. translit 			end 		end 		 		if system == "ALA-LC" and mw.ustring.find(token, '^[υΥ][^ιΙ]*$') then 			translit = translit:gsub('u', 'y'):gsub('U', 'Y') 		end 		 		-- Remove macron from a vowel that has a circumflex. 		if mw.ustring.find(translit, macron_circumflex) then 			translit = translit:gsub(macron, ) 		end 		 		-- Capitalize first character of transliteration. 		if token ~= mw.ustring.lower(token) then 			translit = mw.ustring.gsub(translit, "^.", mw.ustring.upper) 		end 		 		table.insert(output, translit) 	end 	 	return table.concat(output) end  function p.translit(frame) 	local text = frame.args[1] or frame:getParent().args[1] 	 	local system = frame.args.system 	if system == nil or system == "" then 		system = "Wiktionary" 	elseif not (system == "ALA-LC" or system == "Wiktionary") then 		error('Transliteration system in |system= not recognized; choose between "ALA-LC" and "Wiktionary"') 	end 	 	local transliteration = p.transliterate(text, system) 	return '' .. transliteration .. '' end  function p.bare_translit(frame) 	return p.transliterate(frame.args[1] or frame:getParent().args[1]) end  return p