Difference between revisions of "Module:Sandbox/Erutuon/UTF-8"

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blackwiki>Erutuon
(for what do not belong to any of the categories (and may be invalid?))
blackwiki>Anomalocaris
m (<code>...<code> → <code>...</code>)
Line 123: Line 123:
 
bytes:forEach(
 
bytes:forEach(
 
function(byteString)
 
function(byteString)
table.insert(output, "| <code>" .. byteString .. "<code>")
+
table.insert(output, "| <code>" .. byteString .. "</code>")
 
end
 
end
 
)
 
)

Revision as of 04:40, 30 May 2018

An experiment with printing binary digit representations of characters.

Usage

a ~ ¡ á α 𠀀
01100001 01111110 11000010 10100001 11000011 10100001 11001110 10110001 11100001 10111110 10110000 11110000 10100000 10000000 10000000



local p = {}

local bit = require("bit32")
local band = bit.band
local rshift = bit.rshift

function table.forEach(t, func)
	for i, item in ipairs(t) do
		func(item)
	end
end

local function setMt(arr)
	setmetatable(arr, { __index =  table })
end

-- Converts a string representing a number in binary base to a Lua number.
local function binary(stringBinary)
	return tonumber(stringBinary, 2)
end

-- Find the digit at a certain position in a byte.
local function digitAt(number, index)
	if type(number) == "string" then
		number = binary(number)
	end
	return band(rshift(number, 8 - index), 1)
end

-- Returns a table containing bits in a byte, from highest to lowest.
local function getBits(byte)
	local t = {}
	for bit = 8, 1, -1 do
		t[bit] = band(byte, 1)
		byte = rshift(byte, 1)
	end
	return t
end

-- mw.log(table.concat(getBits(rshift(binary("11100001"), 8 - 3))))

-- Do something to each byte in a string; put the result in a table.
local function iterBytes(str, func)
	local out = {}
	for i = 1, #str do
		table.insert(out, func(string.byte(str, i)))
	end
	return out
end

local function makeTag(color)
	return { '<span style="color: ' .. color .. ';">', '</span>' }
end

-- Find leading digits marking ASCII, leading bytes, or continuation bytes,
-- else tag byte as red.
local function markDigits(byteTable)
	local onesCount = 0
	for i, digit in ipairs(byteTable) do
		if digit == 1 then
			onesCount = onesCount + 1
			if onesCount > 4 then
				local tag = makeTag("red")
				table.insert(byteTable, #byteTable, tag[2])
				table.insert(byteTable, 1, tag[1])
			end
		else
			local tag
			-- ASCII (0x00 - 0x7F)
			if onesCount == 0 then
				tag = makeTag("darkgray")
			
			-- continuation bytes
			elseif onesCount == 1 then
				tag = makeTag("chocolate")
			
			-- leading bytes
			else
				tag = makeTag("deeppink")
			end
			table.insert(byteTable, i + 1, tag[2])
			table.insert(byteTable, 1, tag[1])
			return byteTable
		end
	end
	return byteTable
end

local function printBytes(str)
	return table.concat(
		iterBytes(
			str,
			function(byte)
				return table.concat(markDigits(getBits(byte)))
			end
		),
		" "
	)
end

local function makeCharByteTables(str)
	local chars = {}
	local bytes = {}
	local uLen = mw.ustring.len(str)
	for i = 1, uLen do
		local char = mw.ustring.sub(str, i, i)
		table.insert(chars, char)
		table.insert(bytes, printBytes(char))
	end
	return chars, bytes
end

local function print(chars, bytes)
	setMt(chars)
	setMt(bytes)
	local output = { '{| class="wikitable"'}
	chars:forEach(
		function(char)
			table.insert(output, "| " .. char)
		end
	)
	table.insert(output, "|-")
	bytes:forEach(
		function(byteString)
			table.insert(output, "| <code>" .. byteString .. "</code>")
		end
	)
	table.insert(output, "|}")
	return table.concat(output, "\n")
end

function p.show(frame)
	local str = frame.args[1] or "abc πρᾶγμᾰ"
	return print(makeCharByteTables(str))
end

return p