Crate zip_optional
source ·Expand description
§Zip Optional
An iterator type for zipping with an optional iterable.
When the iterable being zipped has no value (i.e. is None), the
initial iterable is effectively zipped with std::iter::repeat(None).
let a = vec![1, 2];
let mut zipped = zip_optional(a, None::<Vec<i32>>);
assert_eq!(zipped.next().unwrap(), (1, None));
assert_eq!(zipped.next().unwrap(), (2, None));
assert_eq!(zipped.next(), None);When the iterable being zipped has a value, the result of a sequence
of Some(_) which contains the items in the iterable being zipped
with.
let a = vec![1, 2];
let b = Some(vec![1, 2]);
let mut zipped = zip_optional(a, b);
assert_eq!(zipped.next().unwrap(), (1, Some(1)));
assert_eq!(zipped.next().unwrap(), (2, Some(2)));
assert_eq!(zipped.next(), None);The provided iterator may also be used inline with other iteration methods, like so:
let mut zipped = vec![1, 2].into_iter().zip_optional(Some(vec![1, 2]));
assert_eq!(zipped.next().unwrap(), (1, Some(1)));
assert_eq!(zipped.next().unwrap(), (2, Some(2)));
assert_eq!(zipped.next(), None);