2 unstable releases
Uses old Rust 2015
0.2.0 | Jul 23, 2017 |
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0.1.0 | Jul 18, 2017 |
#8 in #stacked
9KB
145 lines
duck
It's a peeking duck... geddit?
lib.rs
:
This crate exposes a .peeking()
method, for looking at the next element in
an iterator without consuming it.
Unlike the peekable
method in the standard library, peeking
can be
stacked. This means that chaining multiple calls of peeking
will
increase the number of elements returned by peek
.
Note that this library will .clone()
the elements that are peeked. While
this is not strictly necessary, it does make the implementation much easier
to understand, especially given the lack of generic associated types in
current Rust.
Example
let anatids = vec!["duck", "goose", "swan"];
// Since .peeking() is called twice, this iterator will peek two elements ahead
let mut iter = anatids.into_iter().peeking().peeking();
assert_eq!(iter.peek(), Some(("duck", Some("goose"))));
// Step the iterator twice
iter.next(); iter.next();
// Now we're at "swan", which has no elements after it
assert_eq!(iter.peek(), Some(("swan", None)));