Implement PeekingNext
for PeekingTakeWhile
.
#644
Merged
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This PR implements
PeekingNext
forPeekingTakeWhile
by composing its predicate with the predicate given toPeekingNext::peeking_next
. This allowsItertools::peeking_take_while
to be chained and for subsequent calls, including those across function boundaries, to function as expected while restoring items in the originating iterator.See also #643, which implements
PeekingNext
for mutable references. In combination, these changes allow code to generically accept types implementingPeekingNext
whereItertools::peeking_take_while
can be used by the caller to prepare an iterator and subsequently by a function where restoring items in the originating iterator is important (i.e., the function cannot simply useIterator::peekable
etc., becauseIterator::next
would unconditionally be called on the originating iterator).