Module:Unicode data

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Module documentation

Usage

This module provides functions that access information on Unicode code points. The information is retrieved from data modules generated from the Unicode Character Database, or derived by rules given in the Unicode Specification. It and its submodules were copied from English Wiktionary and then modified; see there for more information.

Parameters and functions

code point

The code point is to be entered as hexadecimal value. For example, U+00A9 © COPYRIGHT SIGN:

|A9hex
|0xA9hex
|0x00A9hex
|0x00a9hex
{{#invoke:Unicode data|lookup|name|0x00A9}} → COPYRIGHT SIGN

Incorrect or unintended results:

169dec: {{#invoke:Unicode data|lookup|name|169}} → LATIN SMALL LETTER U WITH TILDE Red XN —"U+00A9"
©
expected; but is read as 00A9hex (that is, 361dec
U+00A9 {{#invoke:Unicode data|lookup|name|U+00A9}} Red XN —do not use "U+" prefix
غ {{#invoke:Unicode data|lookup|name|غ}} Red XN —cannot enter a character as codepoint

"lookup" and "is" functions

lookup, is
Template-invokable functions that allow access to the functions starting with lookup and is.For most of the functions, add the code point in hexadecimal base as the next parameter. For is|Latin, is|rtl, and is|valid_pagename, add character string. HTML character references in the text are decoded by the module into code points.
For example, {{#invoke:Unicode data|is|Latin|àzàhàr̃iyyā̀}} → true.
Internally, in modules, these functions are named using underscore:
lookup_name|code point
lookup_name
For &A9; ©: {{#invoke:Unicode data|lookup|name|A9}} → COPYRIGHT SIGN

Functions overview

  • Code points: enter hexadecimal value, for example |0x0061 or |61; not |U+0061.
Topic Function Parameter type
(string=by character(s); c.p. by 0xHex value)
Example Returns Character
Unicode character name
|lookup|name
code point lookup|name|0xA9}}
  • {{#invoke:Unicode data|lookup|name|0x0007}}
    • COPYRIGHT SIGN
    • <control-0007>
    • ©
    • &#x0007;
    Scripts
    |lookup|script
    
    code point lookup|script|A061}} Yiii
    Blocks
    |lookup|block
    
    code point lookup|block|A061}} Yi Syllables
    Planes
    |lookup|plane
    
    code point lookup|plane|0xA9}}
  • {{#invoke:Unicode data|lookup|plane|0x1F608}}
    • Basic Multilingual Plane
    • Supplementary Multilingual Plane
    • ©
    • 😈


    General Category
    |lookup|category
    
    code point lookup|category|0xA9}}
  • {{#invoke:Unicode data|lookup|category|0x002B}}
    • So
    • Sm
    • ©
    • +
    Controls
    |is|control
    
    code point lookup|control|A9}}
  • {{#invoke:Unicode data|lookup|control|FFFF}}
    • assigned
    • unassigned
    • ©
    • &#xFFFF;
    Latin script
    |is|Latin
    
    string is|Latin|abcŁíā̀}}
  • {{#invoke:Unicode data|is|Latin|abc文xyz}}
    • true
    • false
    WP:Article title (WP:NCTR)
    |is|valid_pagename
    
    string is|valid_pagename|Main_page}}
  • {{#invoke:Unicode data|is|valid_pagename|# (disambiguation)}}
    • true
    • false
    Bidirectionality, right-to-left scripts
    |is|rtl
    
    string is|rtl|ش}}
  • {{#invoke:Unicode data|is|rtl|34}}
    • true
    • false
    • ش
    • 4
    Combining character
    |is|combining
    
    code point is|combining|0300}}
  • {{#invoke:Unicode data|is|combining|64}}
    • true
    • false
    • ̀
    • d
    Character assignation
    |is|assigned
    
    code point is|assigned|A061}}
  • {{#invoke:Unicode data|is|assigned|FFEF}}
    • true
    • false
    • ;
    Printable
    |is|printable
    
    code point is|printable|0061}}
  • {{#invoke:Unicode data|is|printable|0007}}
  • {{#invoke:Unicode data|is|printable|FFFF}}
    • >true<
    • >false<
    • >false<
    • >a<
    • >&#x0007;<
    • >&#xFFFF;<
    Whitespace_character § Unicode
    |is|whitespace
    
    code point is|whitespace|0x20}}
  • {{#invoke:Unicode data|is|whitespace|0xA0}}
  • {{#invoke:Unicode data|is|whitespace|0x64}}
    • >true<
    • >true< NBSP
    • >false<
    • > <
    • > <
    • >d<
    Alias names
    |aliases
    
    [application unknown]
    • &#x;
    • &#x;
    Combining class
    |
    
    [application unknown]
    • &#x;
    • &#x;
    Age
    |
    
    [application unknown]
    get_best_script
    |get_best_script
    
    [application unknown]

    Data modules

    The data used by functions in this module is found in submodules. Some are generated by AWK scripts shown at User:Kephir/Unicode on English Wiktionary, others by Lua scripts on the /make subpages of the submodules.

    The name data modules (Module:Unicode data/names/xxx) were compiled from UnicodeData.txt. Each one contains, at maximum, code points U+xxx000 to U+xxxFFF.

    Character name data modules,
    organized by first three digits of codepoint in hexadecimal base
    0 1 2 3 4 5 6 7 8 9 A B C D E F
    00x U+0000–
    U+0FFF
    U+1000–
    U+1FFF
    U+2000–
    U+2FFF
    U+3000–
    U+3FFF
    U+4000–
    U+4FFF
    U+A000–
    U+AFFF
    U+D000–
    U+DFFF
    U+F000–
    U+FFFF
    01x U+10000–
    U+10FFF
    U+11000–
    U+11FFF
    U+12000–
    U+12FFF
    U+13000–
    U+13FFF
    U+14000–
    U+14FFF
    U+16000–
    U+16FFF
    U+18000–
    U+18FFF
    U+1A000–
    U+1AFFF
    U+1B000–
    U+1BFFF
    U+1C000–
    U+1CFFF
    U+1D000–
    U+1DFFF
    U+1E000–
    U+1EFFF
    U+1F000–
    U+1FFFF
    0Ex U+E0000–
    U+E0FFF

    Copyright

    The Unicode database is released by Unicode Inc. under the following terms:

    Copyright © 1991-2018 Unicode, Inc. All rights reserved. Distributed under the Terms of Use in https://www.unicode.org/copyright.html.

    Permission is hereby granted, free of charge, to any person obtaining a copy of the Unicode data files and any associated documentation (the "Data Files") or Unicode software and any associated documentation (the "Software") to deal in the Data Files or Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, and/or sell copies of the Data Files or Software, and to permit persons to whom the Data Files or Software are furnished to do so, provided that either (a) this copyright and permission notice appear with all copies of the Data Files or Software, or (b) this copyright and permission notice appear in associated Documentation.

    THE DATA FILES AND SOFTWARE ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THE DATA FILES OR SOFTWARE.

    Except as contained in this notice, the name of a copyright holder shall not be used in advertising or otherwise to promote the sale, use or other dealings in these Data Files or Software without prior written authorization of the copyright holder.

    Known issues

    • Reading data like Module:Unicode data/aliases not provided nor documented
    • Test fail: lookup_category U+FFFF (<noncharacter-FFFF>) expected: Cn.
    {{#invoke:Unicode data|lookup|category|0xFFFF}} → [Nil]

    See also

    • Named entities: for example, U+22C1 N-ARY LOGICAL OR: {{#invoke:LoadData|Numcr2namecr|0x22C1}} → &bigvee;, &Vee;, &xvee;

    local p = {}
    
    local floor = math.floor
    
    local function errorf(level, ...)
    	if type(level) == "number" then
    		return error(string.format(...), level + 1)
    	else -- level is actually the format string.
    		return error(string.format(level, ...), 2)
    	end
    end
    
    local function binary_range_search(codepoint, ranges)
    	local low, mid, high
    	low, high = 1, ranges.length or require "Module:TableTools".length(ranges)
    	while low <= high do
    		mid = floor((low + high) / 2)
    		local range = ranges[mid]
    		if codepoint < range[1] then
    			high = mid - 1
    		elseif codepoint <= range[2] then
    			return range, mid
    		else
    			low = mid + 1
    		end
    	end
    	return nil, mid
    end
    p.binary_range_search = binary_range_search
    
    --[[
    local function linear_range_search(codepoint, ranges)
    	for i, range in ipairs(ranges) do
    		if range[1] <= codepoint and codepoint <= range[2] then
    			return range
    		end
    	end
    end
    --]]
    
    -- Load a module by indexing "loader" with the name of the module minus the
    -- "Module:Unicode data/" part. For instance, loader.blocks returns
    -- [[Module:Unicode data/blocks]]. If a module cannot be loaded, false will be
    -- returned.
    local loader = setmetatable({}, {
    	__index = function (self, key)
    		local success, data = pcall(mw.loadData, "Module:Unicode data/" .. key)
    		if not success then
    			data = false
    		end
    		self[key] = data
    		return data
    	end
    })
    
    -- For the algorithm used to generate Hangul Syllable names,
    -- see "Hangul Syllable Name Generation" in section 3.12 of the
    -- Unicode Specification:
    -- https://www.unicode.org/versions/Unicode11.0.0/ch03.pdf
    local name_hooks = {
    	{     0x00,     0x1F, "<control-%04X>" }, -- C0 control characters
    	{     0x7F,     0x9F, "<control-%04X>" }, -- DEL and C1 control characters
    	{   0x3400,   0x4DBF, "CJK UNIFIED IDEOGRAPH-%04X" }, -- CJK Ideograph Extension A
    	{   0x4E00,   0x9FFF, "CJK UNIFIED IDEOGRAPH-%04X" }, -- CJK Ideograph
    	{   0xAC00,   0xD7A3, function (codepoint) -- Hangul Syllables
    		local Hangul_data = loader.Hangul
    		local syllable_index = codepoint - 0xAC00
    
    		return ("HANGUL SYLLABLE %s%s%s"):format(
    			Hangul_data.leads[floor(syllable_index / Hangul_data.final_count)],
    			Hangul_data.vowels[floor((syllable_index % Hangul_data.final_count)
    				/ Hangul_data.trail_count)],
    			Hangul_data.trails[syllable_index % Hangul_data.trail_count]
    		)
    	end },
    	-- High Surrogates, High Private Use Surrogates, Low Surrogates
    	{   0xD800,   0xDFFF, "<surrogate-%04X>" },
    	{   0xE000,   0xF8FF, "<private-use-%04X>" }, -- Private Use
    	-- CJK Compatibility Ideographs
    	{   0xF900,   0xFA6D, "CJK COMPATIBILITY IDEOGRAPH-%04X" },
    	{   0xFA70,   0xFAD9, "CJK COMPATIBILITY IDEOGRAPH-%04X" },
    	{  0x17000,  0x187F7, "TANGUT IDEOGRAPH-%04X" }, -- Tangut Ideograph
    	{  0x18800,  0x18AFF, function (codepoint)
    		return ("TANGUT COMPONENT-%03d"):format(codepoint - 0x187FF)
    	end },
    	{  0x18D00,  0x18D08, "TANGUT IDEOGRAPH-%04X" }, -- Tangut Ideograph Supplement
    	{  0x1B170,  0x1B2FB, "NUSHU CHARACTER-%04X" }, -- Nushu
    	{  0x20000,  0x2A6DF, "CJK UNIFIED IDEOGRAPH-%04X" }, -- CJK Ideograph Extension B
    	{  0x2A700,  0x2B739, "CJK UNIFIED IDEOGRAPH-%04X" }, -- CJK Ideograph Extension C
    	{  0x2B740,  0x2B81D, "CJK UNIFIED IDEOGRAPH-%04X" }, -- CJK Ideograph Extension D
    	{  0x2B820,  0x2CEA1, "CJK UNIFIED IDEOGRAPH-%04X" }, -- CJK Ideograph Extension E
    	{  0x2CEB0,  0x2EBE0, "CJK UNIFIED IDEOGRAPH-%04X" }, -- CJK Ideograph Extension F
    	-- CJK Compatibility Ideographs Supplement (Supplementary Ideographic Plane)
    	{  0x2F800,  0x2FA1D, "CJK COMPATIBILITY IDEOGRAPH-%04X" },
    	{  0xE0100,  0xE01EF, function (codepoint) -- Variation Selectors Supplement
    		return ("VARIATION SELECTOR-%d"):format(codepoint - 0xE0100 + 17)
    	end},
    	{  0x30000,  0x3134A, "CJK UNIFIED IDEOGRAPH-%04X" }, -- CJK Ideograph Extension G
    	{  0x31350,  0x323AF, "CJK UNIFIED IDEOGRAPH-%04X" }, -- CJK Ideograph Extension H
    	{  0x2EBF0,  0x2EE5D, "CJK UNIFIED IDEOGRAPH-%04X" }, -- CJK Ideograph Extension I
    	{  0xF0000,  0xFFFFD, "<private-use-%04X>" }, -- Plane 15 Private Use
    	{ 0x100000, 0x10FFFD, "<private-use-%04X>" }  -- Plane 16 Private Use
    }
    name_hooks.length = #name_hooks
    
    local name_range_cache
    
    local function generate_name(data, codepoint)
    	if type(data) == "string" then
    		return data:format(codepoint)
    	else
    		return data(codepoint)
    	end
    end
    
    --[[
    -- Checks that the code point is a number and in range.
    -- Does not check whether code point is an integer.
    -- Not used
    local function check_codepoint(funcName, argIdx, val)
    	require 'libraryUtil'.checkType(funcName, argIdx, val, 'number')
    	if codepoint < 0 or 0x10FFFF < codepoint then
    		errorf("Codepoint %04X out of range", codepoint)
    	end
    end
    --]]
    
    function p.is_noncharacter(codepoint)
    	-- U+FDD0-U+FDEF and all code points ending in FFFE or FFFF are Unassigned
    	-- (Cn) and specifically noncharacters:
    
    	-- https://www.unicode.org/faq/private_use.html#nonchar4
    	return 0xFDD0 <= codepoint and (codepoint <= 0xFDEF
    			or floor(codepoint % 0x10000) >= 0xFFFE)
    end
    
    -- https://www.unicode.org/versions/Unicode11.0.0/ch04.pdf, section 4.8
    function p.lookup_name(codepoint)
    	if p.is_noncharacter(codepoint) then
    		return ("<noncharacter-%04X>"):format(codepoint)
    	end
    
    	if name_range_cache -- Check if previously used "name hook" applies to this code point.
    			and codepoint >= name_range_cache[1]
    			and codepoint <= name_range_cache[2] then
    		return generate_name(name_range_cache[3], codepoint)
    	end
    	
    	local range = binary_range_search(codepoint, name_hooks)
    	if range then
    		name_range_cache = range
    		return generate_name(range[3], codepoint)
    	end
    
    	local data = loader[('names/%03X'):format(codepoint / 0x1000)]
    	
    	if data and data[codepoint] then
    		return data[codepoint]
    	
    	-- Unassigned (Cn) consists of noncharacters and reserved characters.
    	-- The character has been established not to be a noncharacter,
    	-- and if it were assigned, its name would already been retrieved,
    	-- so it must be reserved.
    	else
    		return ("<reserved-%04X>"):format(codepoint)
    	end
    end
    
    function p.lookup_image(codepoint)
    	local data = loader[('images/%03X'):format(codepoint / 0x1000)]
    	
    	if data then
    		return data[codepoint]
    	end
    end
    
    local planes = {
    	[ 0] = "Basic Multilingual Plane";
    	[ 1] = "Supplementary Multilingual Plane";
    	[ 2] = "Supplementary Ideographic Plane";
    	[ 3] = "Tertiary Ideographic Plane";
    	[14] = "Supplementary Special-purpose Plane";
    	[15] = "Supplementary Private Use Area-A";
    	[16] = "Supplementary Private Use Area-B";
    }
    
    -- Load [[Module:Unicode data/blocks]] if needed and assign it to this variable.
    local blocks
    
    local function block_iter(blocks, i)
    	i = i + 1
    	local data = blocks[i]
    	if data then
    		 -- Unpack doesn't work on tables loaded with mw.loadData.
    		return i, data[1], data[2], data[3]
    	end
    end
    
    -- An ipairs-type iterator generator for the list of blocks.
    function p.enum_blocks()
    	local blocks = loader.blocks
    	return block_iter, blocks, 0
    end
    
    function p.lookup_plane(codepoint)
    	local i = floor(codepoint / 0x10000)
    	return planes[i] or ("Plane %u"):format(i)
    end
    
    function p.lookup_block(codepoint)
    	local blocks = loader.blocks
    	local range = binary_range_search(codepoint, blocks)
    	if range then
    		return range[3]
    	else
    		return "No Block"
    	end
    end
    
    function p.get_block_info(name)
    	for i, block in ipairs(loader.blocks) do
    		if block[3] == name then
    			return block
    		end
    	end
    end
    
    function p.is_valid_pagename(pagename)
    	local has_nonws = false
    
    	for cp in mw.ustring.gcodepoint(pagename) do
    		if (cp == 0x0023) -- #
    		or (cp == 0x005B) -- [
    		or (cp == 0x005D) -- ]
    		or (cp == 0x007B) -- {
    		or (cp == 0x007C) -- |
    		or (cp == 0x007D) -- }
    		or (cp == 0x180E) -- MONGOLIAN VOWEL SEPARATOR
    		or ((cp >= 0x2000) and (cp <= 0x200A)) -- spaces in General Punctuation block
    		or (cp == 0xFFFD) -- REPLACEMENT CHARACTER
    		then
    			return false
    		end
    
    		local printable, result = p.is_printable(cp)
    		if not printable then
    			return false
    		end
    
    		if result ~= "space-separator" then
    			has_nonws = true
    		end
    	end
    
    	return has_nonws
    end
    
    local function manual_unpack(what, from)
    	if what[from + 1] == nil then
    		return what[from]
    	end
    	
    	local result = {}
    	from = from or 1
    	for i, item in ipairs(what) do
    		if i >= from then
    			table.insert(result, item)
    		end
    	end
    	return unpack(result)
    end
    
    local function compare_ranges(range1, range2)
    	return range1[1] < range2[1]
    end
    
    -- Creates a function to look up data in a module that contains "singles" (a
    -- code point-to-data map) and "ranges" (an array containing arrays that contain
    -- the low and high code points of a range and the data associated with that
    -- range).
    -- "loader" loads and returns the "singles" and "ranges" tables.
    -- "match_func" is passed the code point and either the data or the "dots", and
    -- generates the final result of the function.
    -- The varargs ("dots") describes the default data to be returned if there wasn't
    -- a match.
    -- In case the function is used more than once, "cache" saves ranges that have
    -- already been found to match, or a range whose data is the default if there
    -- was no match.
    local function memo_lookup(data_module_subpage, match_func, ...)
    	local dots = { ... }
    	local cache = {}
    	local singles, ranges
    
    	return function (codepoint)
    		if not singles then
    			local data_module = loader[data_module_subpage]
    			singles, ranges = data_module.singles, data_module.ranges
    		end
    
    		if singles[codepoint] then
    			return match_func(codepoint, singles[codepoint])
    		end
    
    		local range = binary_range_search(codepoint, cache)
    		if range then
    			return match_func(codepoint, manual_unpack(range, 3))
    		end
    		
    		local range, index = binary_range_search(codepoint, ranges)
    		if range then
    			table.insert(cache, range)
    			table.sort(cache, compare_ranges)
    			return match_func(codepoint, manual_unpack(range, 3))
    		end
    		
    		if ranges[index] then
    			local dots_range
    			if codepoint > ranges[index][2] then
    				dots_range = {
    					ranges[index][2] + 1,
    					ranges[index + 1] and ranges[index + 1][1] - 1 or 0x10FFFF,
    					unpack(dots)
    				}
    			else -- codepoint < range[index][1]
    				dots_range = {
    					ranges[index - 1] and ranges[index - 1][2] + 1 or 0,
    					ranges[index][1] - 1,
    					unpack(dots)
    				}
    			end
    			table.sort(cache, compare_ranges)
    		end
    		
    		return match_func(codepoint)
    	end
    end
    
    -- Get a code point's combining class value in [[Module:Unicode data/combining]],
    -- and return whether this value is not zero. Zero is assigned as the default
    -- if the combining class value is not found in this data module.
    -- That is, return true if character is combining, or false if it is not.
    -- See https://www.unicode.org/reports/tr44/#Canonical_Combining_Class_Values for
    -- more information.
    p.is_combining = memo_lookup(
    	"combining",
    	function (codepoint, combining_class)
    		return combining_class and combining_class ~= 0 or false
    	end,
    	0)
    
    function p.add_dotted_circle(str)
    	return (mw.ustring.gsub(str, ".",
    		function(char)
    			if p.is_combining(mw.ustring.codepoint(char)) then
    				return '◌' .. char
    			end
    		end))
    end
    
    local lookup_control = memo_lookup(
    	"control",
    	function (codepoint, ccc)
    		return ccc or "assigned"
    	end,
    	"assigned")
    p.lookup_control = lookup_control
    
    function p.is_assigned(codepoint)
    	return lookup_control(codepoint) ~= "unassigned"
    end
    
    function p.is_printable(codepoint)
    	local result = lookup_control(codepoint)
    	return (result == "assigned") or (result == "space-separator"), result
    end
    
    function p.is_whitespace(codepoint)
    	local result = lookup_control(codepoint)
    	return (result == "space-separator"), result
    end
    
    p.lookup_category = memo_lookup(
    	"category",
    	function (codepoint, category)
    		return category
    	end,
    	"Cn")
    
    local lookup_script = memo_lookup(
    	"scripts",
    	function (codepoint, script_code)
    		return script_code or 'Zzzz'
    	end,
    	"Zzzz")
    p.lookup_script = lookup_script
    
    function p.get_best_script(str)
    	-- Check type of argument, because mw.text.decode coerces numbers to strings!
    	require "libraryUtil".checkType("get_best_script", 1, str, "string")
    	
    	-- Convert HTML character references (including named character references,
    	-- or character entities) to characters.
    	str = mw.text.decode(str, true)
    	
    	local scripts = {}
    	for codepoint in mw.ustring.gcodepoint(str) do
    		local script = lookup_script(codepoint)
    		
    		-- Ignore "Inherited", "Undetermined", or "Uncoded" scripts.
    		if not (script == "Zyyy" or script == "Zinh" or script == "Zzzz") then
    			scripts[script] = true
    		end
    	end
    	
    	-- If scripts does not contain two or more keys,
    	-- return first and only key (script code) in table.
    	if not next(scripts, next(scripts)) then
    		return next(scripts)
    	end -- else return majority script, or else "Zzzz"?
    end
    
    function p.is_Latin(str)
    	require "libraryUtil".checkType("get_best_script", 1, str, "string")
    	str = mw.text.decode(str, true)
    	
    	-- Search for the leading bytes that introduce the UTF-8 encoding of the
    	-- code points U+0340-U+10FFFF. If they are not found and there is at least
    	-- one Latin-script character, the string counts as Latin, because the rest
    	-- of the characters can only be Zyyy, Zinh, and Zzzz.
    	-- The only scripts found below U+0370 (the first code point of the Greek
    	-- and Coptic block) are Latn, Zyyy, Zinh, and Zzzz.
    	-- See the codepage in the [[UTF-8]] article.
    	if not str:find "[\205-\244]" then
    		for codepoint in mw.ustring.gcodepoint(str) do
    			if lookup_script(codepoint) == "Latn" then
    				return true
    			end
    		end
    	end
    	
    	local Latn = false
    	
    	for codepoint in mw.ustring.gcodepoint(str) do
    		local script = lookup_script(codepoint)
    		
    		if script == "Latn" then
    			Latn = true
    		elseif not (script == "Zyyy" or script == "Zinh"
    				or script == "Zzzz") then
    			return false
    		end
    	end
    	
    	return Latn
    end
    
    -- Checks that a string contains only characters belonging to right-to-left
    -- scripts, or characters of ignorable scripts.
    function p.is_rtl(str)
    	require "libraryUtil".checkType("get_best_script", 1, str, "string")
    	str = mw.text.decode(str, true)
    	
    	-- Search for the leading bytes that introduce the UTF-8 encoding of the
    	-- code points U+0580-U+10FFFF. If they are not found, the string can only
    	-- have characters from a left-to-right script, because the first code point
    	-- in a right-to-left script is U+0591, in the Hebrew block.
    	if not str:find "[\214-\244]" then
    		return false
    	end
    	
    	local result = false
    	local rtl = loader.scripts.rtl
    	for codepoint in mw.ustring.gcodepoint(str) do
    		local script = lookup_script(codepoint)
    		
    		if rtl[script] then
    			result = true
    		elseif not (script == "Zyyy" or script == "Zinh"
    				or script == "Zzzz") then
    			return false
    		end
    	end
    	
    	return result
    end
    
    
    --[[--------------------------< I S _ R T L _ F R A M E >------------------------------------------------------
    
    external entry from an {{#invoke:}} to determine if a string of text is rtl.  Strips html and html-like tags so
    that those tags don't corrupt the is-rtl-is-not-rtl determination; this added for the cases where the rtl text
    has <br /> tags.
    
    ]]
    
    function p.is_rtl_frame (frame)
    	local str = frame.args[1];													-- get the string from the {{#invoke:}} frame
    	str = str:gsub ('%b<>', '');												-- strip any html and html-like tags
    	return p.is_rtl (str);														-- return if whatever remains rtl; false else
    end
    
    
    local function get_codepoint(args, arg)
    	local codepoint_string = args[arg]
    		or errorf(2, "Parameter %s is required", tostring(arg))
    	local codepoint = tonumber(codepoint_string, 16)
    		or errorf(2, "Parameter %s is not a code point in hexadecimal base",
    			tostring(arg))
    	if not (0 <= codepoint and codepoint <= 0x10FFFF) then
    		errorf(2, "code point in parameter %s out of range", tostring(arg))
    	end
    	return codepoint
    end
    
    local function get_func(args, arg, prefix)
    	local suffix = args[arg]
    		or errorf(2, "Parameter %s is required", tostring(arg))
    	suffix = mw.text.trim(suffix)
    	local func_name = prefix .. suffix
    	local func = p[func_name]
    		or errorf(2, "There is no function '%s'", func_name)
    	return func
    end
    
    -- This function allows any of the "lookup" functions to be invoked. The first
    -- parameter is the word after "lookup_"; the second parameter is the code point
    -- in hexadecimal base.
    function p.lookup(frame)
    	local func = get_func(frame.args, 1, "lookup_")
    	local codepoint = get_codepoint(frame.args, 2)
    	local result = func(codepoint)
    	if func == p.lookup_name then
    		-- Prevent code point labels such as <control-0000> from being
    		-- interpreted as HTML tags.
    		result = result:gsub("<", "&lt;")
    	end
    	return result
    end
    
    function p.is(frame)
    	local func = get_func(frame.args, 1, "is_")
    	
    	-- is_Latin and is_valid_pagename take strings.
    	if func == p.is_Latin or func == p.is_valid_pagename or func == p.is_rtl then
    		return (func(frame.args[2]))
    	else -- The rest take code points.
    		local codepoint = get_codepoint(frame.args, 2)
    		return (func(codepoint)) -- Adjust to one result.
    	end
    end
    
    return p