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