Bikeshed composability

We should think about how to improve composability in Rust.

Examples

• We should have str::any() and list::any() like vec::any(). But why duplicate the implementation when they all simply expect a stream of values?

• vec::any2() is like vec::any() operating on two lists instead of one. In Haskell you would simply would do any foo $ zip ls and would not need a special function any2. In Rust vec::zip() creates a whole new vector, but we'd need something like vec::zip_iter() that only iterates over the zipped-list => generates a stream of tuples.

Proposals

Iterators

Why were iterators ruled out? I think they would be ideal for composability.

• If we had something like str::iterator() -> iterator<T>, list::iterator() -> iterator<T>, vec::iterator() -> iterator<T>
• we would only need one any(iterator<T>) -> bool
• and could get rid of duplicate str::any(), list::any() and vec::any() as well any vec::any2()

Type classes / interfaces

• imlpementation via type classes / interfaces