Module:Unicode data

local m_str_utils = require("Module:string utilities")

local cp = m_str_utils.codepoint
local gcodepoint = m_str_utils.gcodepoint
local gsub = string.gsub
local u = m_str_utils.char

local export = {}
local udata = mw.loadData("Module:Unicode data/data")

local floor = math.floor

local function errorf(first_arg, ...)
	if type(first_arg) == "number" then
		return error(string.format(...), first_arg + 1)
	else
		return error(string.format(first_arg, ...), 2)
	end
end

local function binary_range_search(codepoint, ranges)
	local low, mid, high
	low, high = 1, ranges.length or require "Module:table".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
export.binary_range_search = binary_range_search

local function linear_range_search(codepoint, ranges)
	for i, range in ipairs(ranges) do
		if codepoint < range[1] then
			break
		elseif 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/latest/ch03.pdf
-- For most of the name rules given here, see the subsection
-- "Unicode Name Property" in section 4.8 (Name) and the table 4-8
-- (Name Derivation Rule Prefix Strings):
-- https://www.unicode.org/versions/latest/ch04.pdf
local name_hooks = {
	{   0x0000,   0x001F, "<control-%04X>" }, -- C0 control characters
	{   0x007F,   0x009F, "<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" },
	{   0xFDD0,   0xFDEF, "<noncharacter-%04X>" },
	{   0xFE00,   0xFE0F, function (codepoint) -- Variation Selectors Supplement
		return ("VARIATION SELECTOR-%d"):format(codepoint - 0xFE00 + 1)
	end},
    {  0x13460,  0x143FA, "EGYPTIAN HIEROGLYPH-%04X" }, -- Egyptian Hieroglyphs Extended-A
	{  0x17000,  0x187F7, "TANGUT IDEOGRAPH-%04X" }, -- Tangut
	{  0x18800,  0x18AFF, function (codepoint)
		return ("TANGUT COMPONENT-%03d"):format(codepoint - 0x187FF)
	end },
	{  0x18B00,  0x18CD5, "KHITAN SMALL SCRIPT CHARACTER-%04X" }, -- Khitan Small Script
	{  0x18CFF,  0x18CFF, "KHITAN SMALL SCRIPT CHARACTER-%04X" },
	{  0x18D00,  0x18D08, "TANGUT IDEOGRAPH-%04X" }, -- Tangut 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
	{  0x2EBF0,  0x2EE5D, "CJK UNIFIED IDEOGRAPH-%04X" }, -- CJK Ideograph Extension I
	-- CJK Compatibility Ideographs Supplement (Supplementary Ideographic Plane)
	{  0x2F800,  0x2FA1D, "CJK COMPATIBILITY IDEOGRAPH-%04X" },
	{  0x30000,  0x3134A, "CJK UNIFIED IDEOGRAPH-%04X" }, -- CJK Ideograph Extension G
	{  0x31350,  0x323AF, "CJK UNIFIED IDEOGRAPH-%04X" }, -- CJK Ideograph Extension H
	{  0xE0100,  0xE01EF, function (codepoint) -- Variation Selectors Supplement
		return ("VARIATION SELECTOR-%d"):format(codepoint - 0xE0100 + 17)
	end},
	{  0xF0000,  0xFFFFD, "<private-use-%04X>" }, -- Plane 15 Private Use
	{ 0x100000, 0x10FFFD, "<private-use-%04X>" }, -- Plane 16 Private Use
}
name_hooks.length = #name_hooks
--[[ Add another - in this line to test the code point ordering in name_hooks.
local i = 1
local function print_it(a, b, c)
	if type(c) == "string" then
		mw.log(c:format(a), c:format(b))
	else
		mw.log(c(a), c(b))
	end
end
while true do
	local first, second = name_hooks[i], name_hooks[i + 1]
	if not (first and second) then break end
	local message
	if not (first[1] < first[2] and first[2] < second[1] and second[1] < second[2]) then
		message = "Bad name label ordering at index " .. i .. ":"
	elseif second[1] == first[2] + 1 and second[3] == first[3] then
		message = "Name hooks can be merged at index " .. i .. ":"
	end
	if message then
		mw.log(message)
		print_it(unpack(first))
		print_it(unpack(second))
	end
	i = i + 1
end
--]]

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
--]]

-- https://www.unicode.org/versions/latest/ch04.pdf, section 4.8
function export.lookup_name(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
	if codepoint >= 0xFFFE and floor(codepoint % 0x10000) >= 0xFFFE 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 export.lookup_image(codepoint)
	local data = loader[('images/%03X'):format(codepoint / 0x1000)]
	
	if data then
		return data[codepoint]
	end
end

function export.lookup_image_emoji(codepoint)
	local data = loader[('emoji_images/%03X'):format(codepoint / 0x1000)]
	
	if data then
		return data[codepoint]
	end
end

-- 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[3], data[1], data[2]
	end
end

-- An ipairs-type iterator generator for the list of blocks.
function export.enum_blocks()
	local blocks = loader.blocks
	return block_iter, blocks, 0
end

function export.get_block_range(name)
	for i, block in ipairs(loader.blocks) do
		if block[3] == name then
			return block[1], block[2]
		end
	end
end

function export.lookup_plane(codepoint)
	local i = floor(codepoint / 0x10000)
	return udata.planes[i] or ("Plane %u"):format(i)
end

function export.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 export.get_block_info(name)
	for i, block in ipairs(loader.blocks) do
		if block[3] == name then
			return block
		end
	end
end

function export.is_valid_pagename(pagename)
	local has_nonws = false

	for codepoint in gcodepoint(pagename) do
		if (codepoint == 0x0023) -- #
		or (codepoint == 0x005B) -- [
		or (codepoint == 0x005D) -- ]
		or (codepoint == 0x007B) -- {
		or (codepoint == 0x007C) -- |
		or (codepoint == 0x007D) -- }
		or (codepoint == 0x180E) -- MONGOLIAN VOWEL SEPARATOR
		or ((codepoint >= 0x2000) and (codepoint <= 0x200A)) -- spaces in General Punctuation block
		or (codepoint == 0xFFFD) -- REPLACEMENT CHARACTER
		then
			return false
		end

		local printable, result = export.is_printable(codepoint)
		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 codepoint_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.insert(cache, dots_range)
			table.sort(cache, compare_ranges)
		end
		
		return match_func(codepoint, unpack(dots))
	end
end

-- Return a character's combining class value from [[Module:Unicode data/combining classes]],
-- or otherwise 0, which is treated as the default value.
do
	local combining
	
	function export.combining_class(ch)
		combining = combining or mw.loadData("Module:Unicode data/combining classes")
		return combining[type(ch) == "number" and u(ch) or ch] or 0
	end
end

-- FIXME: Some combining characters have a combining class of 0, so this needs rethinking.
function export.is_combining(ch)
	return export.combining_class(ch) ~= 0
end

do
	local function dotted_circle(ch)
		if export.combining_class(ch) ~= 0 then
			return "◌" .. ch
		end
	end
	
	function export.add_dotted_circle(str)
		return (gsub(str, ".[\128-\191]*", dotted_circle))
	end
end

local lookup_control = codepoint_lookup(
	"control",
	function (codepoint, ccc)
		return ccc or "assigned"
	end,
	"assigned")
export.lookup_control = lookup_control

function export.is_assigned(codepoint)
	return lookup_control(codepoint) ~= "unassigned"
end

function export.is_printable(codepoint)
	local result = lookup_control(codepoint)
	return (result == "assigned") or (result == "space-separator"), result
end

function export.is_whitespace(codepoint)
	local result = lookup_control(codepoint)
	return (result == "space-separator"), result
end

export.lookup_category = codepoint_lookup(
	"category",
	function (codepoint, category)
		return category
	end,
	"Cn"
)

function export.get_category_long_name(category)
	return loader["category"].long_names[category]
end

export.lookup_script = codepoint_lookup(
	"scripts",
	function (codepoint, script)
		return script
	end,
	"Zzzz"
)

function export.get_script_alias(script)
	return loader["scripts"].aliases[script]
end

function export.get_entry_title(codepoint)
	if udata.unsupported_title[codepoint] then
		return udata.unsupported_title[codepoint]
	end
	if lookup_control(codepoint) ~= "assigned" then
		return nil
	end
	return u(codepoint)
end

return export