debug.lua

local bit = require("bit")

local box={
	ud="│",
	lr="─",
	ur="└",
	rd="┌",
	ld="┐",
	lu="┘",
	lrd="┬",
	udr="├",
	x="┼",
	lud="┤",
	lur="┴",
	e="[]"
}

--[[local box={
	ud="|",
	lr="-",
	ur="\\",
	rd="/",
	ld="\\",
	lu="/",
	e="[]"
}]]

function utf8len(s)
	local t=0
	for l1=1,#s do
		local c=s:byte(l1)
		if bit.band(c,0xC0)~=0x80 then
			t=t+1
		end
	end
	return t
end

function utf8sub(s,b,e)
	e=e or utf8len(s)
	return s:sub(b,e)
end

local function txtbl(s,mx)
	if s=="" then
		if mx then
			return {(" "):rep(mx)},mx
		end
		return {},0
	end
	s=tostring(s)
	local o={}
	for c in s:gmatch("[^\r\n]+") do
		table.insert(o,c)
	end
	mx=mx or 0
	for l1=1,#o do
		mx=math.max(mx,utf8len(o[l1]))
	end
	for l1=1,#o do
		o[l1]=o[l1]..(" "):rep(mx-utf8len(o[l1]))
	end
	return o,mx
end

function consoleBox(s)
	local t,l=txtbl(s)
	if #t == 1 then
		return "[" .. t[1] .. "]"
	end
	for l1=1,#t do
		t[l1]=box.ud..t[l1]..box.ud
	end
	table.insert(t,1,box.rd..(box.lr:rep(l))..box.ld)
	table.insert(t,box.ur..(box.lr:rep(l))..box.lu)
	return table.concat(t,"\n")
end

function consoleCat(a,b,al,bl)
	local at,al=txtbl(a,al)
	local bt,bl=txtbl(b,bl)
	if #at==#bt then
		for l1=1,#bt do
			bt[l1]=at[l1]..bt[l1]
		end
		return table.concat(bt,"\n")
	end
	if al==0 then
		return table.concat(bt,"\n")
	elseif bl==0 then
		return table.concat(at,"\n")
	end
	local ml = math.max(#at, #bt)
	for l1=1,math.floor((#bt-#at)/2) do
		table.insert(at,1,(" "):rep(al))
	end
	for l1=#at+1,ml do
		table.insert(at,(" "):rep(al))
	end
	for l1=1,math.floor((#at-#bt)/2) do
		table.insert(bt,1,(" "):rep(bl))
	end
	for l1=#bt+1,ml do
		table.insert(bt,(" "):rep(bl))
	end
	for l1=1,ml do
		at[l1]=at[l1]..bt[l1]
	end
	return table.concat(at,"\n")
end

function consoleSub(txt,sx,sy,ex,ey)
	local tb=txtbl(txt)
	if sy<0 then
		sy=(#tb)+sy+1
	end
	if ey<0 then
		ey=(#tb)+ey+1
	end
	for l1=1,#tb do
		tb[l1]=utf8sub(tb[l1],sx,ex)
	end
	for l1=1,sy-1 do
		tb[l1]=""
	end
	for l1=ey+1,#tb do
		tb[l1]=""
	end
	return table.concat(tb,"\n")
end

function consoleTable(t)
	local ncols=0
	local nrows=0
	for k,v in pairs(t) do
		nrows=math.max(nrows,k)
		for n,l in pairs(v) do
			ncols=math.max(ncols,n)
		end
	end
	local wcols={}
	local hrows={}
	for l1=1,nrows do
		for l2=1,ncols do
			local d,mx=txtbl(t[l1][l2] or "")
			wcols[l2]=math.max(wcols[l2] or 0,mx)
			hrows[l1]=math.max(hrows[l1] or 0,#d)
		end
	end
	local sp={}
	for l1=1,ncols do
		table.insert(sp,(box.lr):rep(wcols[l1]))
	end
	local ocols={box.rd..table.concat(sp,box.lrd)..box.ld}
	for l1=1,nrows do
		local orow={}
		for l2=1,ncols do
			table.insert(orow,table.concat(txtbl(t[l1][l2] or "",wcols[l2]),"\n"))
			table.insert(orow,(box.ud.."\n"):rep(hrows[l1]))
		end
		local o=(box.ud.."\n"):rep(hrows[l1])
		for l2=1,#orow do
			o=consoleCat(o,orow[l2])
		end
		table.insert(ocols,o)
		table.insert(ocols,l1==nrows and (box.ur..table.concat(sp,box.lur)..box.lu) or (box.udr..table.concat(sp,box.x)..box.lud))
	end
	return table.concat(ocols,"\n")
end

local function _cserialize(t,r)
	r=r or {} -- recursive table detection
	if r[t] then
		return tostring(t) -- just show table pointer
	end
	local tpe=type(t)
	if tpe=="table" then
		local err,res=pcall(function()
			local ok={}
			local ov={}
			local u={}
			local n=1
			r[t]=true
			while t[n]~=nil do
				u[n]=true
				table.insert(ok," ")
				table.insert(ov,consoleCat("   ",_cserialize(t[n],r)))
				n=n+1
			end
			local oi={}
			for k,v in pairs(t) do
				if not u[k] then
					table.insert(oi,{k,v})
				end
			end
			if #oi==0 then
				for l1=1,#ov do
					ov[l1]=consoleSub(ov[l1],4,1,-1,-1)
				end
			end
			table.sort(oi,function(a,b)
				return tostring(a[1])<tostring(b[1])
			end)
			for k,v in ipairs(oi) do
				local kr
				if type(v[1])=="string" and not v[1]:match("%s") then
					kr=v[1]
				else
					kr=_cserialize(v[1], r)
				end
				table.insert(ok, kr)
				table.insert(ov,consoleCat(" = ", _cserialize(v[2],r)))
			end
			if #ok == 0 then
				return box.e
			end
			local _ -- throw away value
			local kl = 0 -- 
			for k,v in pairs(ok) do
				if v ~= " " then
					_,kl=txtbl(v, kl)
				end
			end
			if kl==0 then
				return consoleBox(table.concat(ov, "\n"))
			end
			local vl=0
			for k,v in pairs(ov) do
				_,vl=txtbl(v, vl)
			end
			local o=""
			for l1=1,#ok do
				o=o..consoleCat(ok[l1], ov[l1], kl, vl).."\n"
			end
			r[t]=nil
			return consoleBox(o)
		end)
		assert(err,res)
		return err and res or tostring(t)
	elseif tpe=="number" then
		if t~=t then
			return "nan"
		elseif t==math.huge then
			return "inf"
		elseif t==-math.huge then
			return "-inf"
		end
		return tostring(t)
	elseif tpe=="string" then
		local o=string.format("%q", t):gsub("\\\n", "\\n"):gsub("%z", "\\z")
		return o
	else
		return tostring(t)
	end
end

function cserialize(t)
	return _cserialize(t)
end