Crate steepen

steepen is a crate used to convert an iterator of elements into an iterator of blocks, given that blocks can be created from an iterator of elements.

Does the contrary of the flatten function, hence the name.

Examples

use steepen::Steepenable;

let iter = vec![("a", 1),("a", 2),("b", 1),("b", 2),("b", 1),("c", 2)].into_iter();

let mut result = iter
.steepen_by::<Vec<(&str, u32)>, _>(
    // letters are different or numbers are descending
    |x, y| x.0 != y.0 || x.1 > y.1
);

assert_eq!(result.next(), Some(vec![("a", 1),("a", 2)]));
assert_eq!(result.next(), Some(vec![("b", 1),("b", 2)]));
assert_eq!(result.next(), Some(vec![("b", 1)]));
assert_eq!(result.next(), Some(vec![("c", 2)]));
assert_eq!(result.next(), None);

Properties

iterators returned by a steepen function respect four principles:

• It won’t be empty
• Elements remain in order, i.e a flatten function reverses it
• Last element of an iterator and first element of the next iterator respect the predicate
• every pair of consecutive element in an iterator don’t respect the predicate

Structs

Separate

Iterator struct that injects None values between elements according to a separator.

Steepen

Iterator that yield blocks of elements in ascending order.

SteepenBy

Iterator that yields blocks of elements separated by a predicate.

SteepenEq

Iterator that yields blocks of equal elements.

SteepenStrict

Iterator that yields blocks of strictly ascending elements.

Traits

Separable

Trait to add separate function

Steepenable

Trait to add steepen functions