import gdb


class KstdVectorPrinter(gdb.ValuePrinter):
    class Iterator:
        def __init__(self, begin: gdb.Value, end: gdb.Value):
            self._item = begin
            self._end = end
            self._count = 0

        def __iter__(self):
            return self

        def __next__(self):
            count = self._count
            self._count = count + 1

            if self._item == self._end:
                raise StopIteration

            element = self._item.dereference()
            self._item = self._item + 1
            return (f"[{count}]", element)

    def __init__(self, val: gdb.Value):
        self.__val = val
        self.__size = int(val["m_size"])
        self.__capacity = int(val["m_capacity"])
        self.__data = val["m_data"]

    def to_string(self):
        return f"vector of length {self.__size}, capacity {self.__capacity}"

    def children(self):
        return self.Iterator(self.__data, self.__data + self.__size)

    def display_hint(self):
        return "array"

    def num_children(self):
        return self.__size