def dec2bin(d, nb=0):
	if d=="x":
		return "x"*nb
	elif d==0:
		b="0"
	else:
		b=""
		while d!=0:
			b="01"[d&1]+b
			d=d>>1
	return b.zfill(nb)

def get_bits(values, low, high=None):
	r = []
	if high is None:
		high = low+1
	for val in values:
		t = (val >> low) & (2**(high-low)-1)
		r.append(t)
	return r

class Dat(list):
	def __init__(self, width):
		self.width = width

	def __getitem__(self, key):
		if isinstance(key, int):
			return get_bits(self, key)
		elif isinstance(key, slice):
			if key.start != None:
				start = key.start
			else:
				start = 0
			if key.stop != None:
				stop = key.stop
			else:
				stop = self.width
			if stop > self.width:
				stop = self.width
			if key.step != None:
				raise KeyError
			return get_bits(self, start, stop)
		else:
			raise KeyError

	def decode_rle(self):
		datas = Dat(self.width-1)
		last_data = 0
		for data in self:
			rle = data >> (self.width-1)
			data = data & (2**(self.width-1)-1)
			if rle:
				for i in range(data):
					datas.append(last_data)
			else:
				datas.append(data)
				last_data = data
		return datas

class Var:
	def __init__(self, name, width, values=[], type="wire", default="x"):
		self.type = type
		self.width = width
		self.name = name
		self.val = default
		self.values = values
		self.vcd_id = None

	def set_vcd_id(self, s):
		self.vcd_id = s

	def __len__(self):
		return len(self.values)

	def change(self, cnt):
		r = ""
		try :
			if self.values[cnt+1] != self.val:
				r += "b"
				r += dec2bin(self.values[cnt+1], self.width)
				r += " "
				r += self.vcd_id
				r += "\n"
				return r
		except :
			return r
		return r

class Dump:
	def __init__(self):
		self.vars = []
		self.vcd_id = "!"

	def add(self, var):
		var.set_vcd_id(self.vcd_id)
		self.vcd_id = chr(ord(self.vcd_id)+1)
		self.vars.append(var)

	def add_from_layout(self, layout, var):
		i=0
		for s, n in layout:
			self.add(Var(s, n, var[i:i+n]))
			i += n

	def __len__(self):
		l = 0
		for var in self.vars:
			l = max(len(var),l)
		return l