Replace collection with iteration

[AbstractiveNord]

I've found a lot of collections, which can be replaced with Iter, save memory and improve performance for first results.
Why collections was used instead of Iter?

[divi255]

Good day,

try suggesting or replacing some. but be careful as your latest patch have broken functionality of "match any". the crate is used in our mission-critical production so I really care about keeping it working properly.