#------------------------------------------------------------------------------- # elftools: common/construct_utils.py # # Some complementary construct utilities # # Eli Bendersky (eliben@gmail.com) # This code is in the public domain #------------------------------------------------------------------------------- from ..construct import Subconstruct, ConstructError, ArrayError class RepeatUntilExcluding(Subconstruct): """ A version of construct's RepeatUntil that doesn't include the last element (which casued the repeat to exit) in the return value. Only parsing is currently implemented. P.S. removed some code duplication """ __slots__ = ["predicate"] def __init__(self, predicate, subcon): Subconstruct.__init__(self, subcon) self.predicate = predicate self._clear_flag(self.FLAG_COPY_CONTEXT) self._set_flag(self.FLAG_DYNAMIC) def _parse(self, stream, context): obj = [] try: context_for_subcon = context if self.subcon.conflags & self.FLAG_COPY_CONTEXT: context_for_subcon = context.__copy__() while True: subobj = self.subcon._parse(stream, context_for_subcon) if self.predicate(subobj, context): break obj.append(subobj) except ConstructError as ex: raise ArrayError("missing terminator", ex) return obj def _build(self, obj, stream, context): raise NotImplementedError('no building') def _sizeof(self, context): raise SizeofError("can't calculate size")