Macro stdcli::izip

macro_rules! izip {
    ( @ closure $ p : pat => $ tup : expr ) => { ... };
    (
@ closure $ p : pat => ( $ ( $ tup : tt ) * ) , $ _iter : expr $ (
, $ tail : expr ) * ) => { ... };
    ( $ first : expr $ ( , $ rest : expr ) * $ ( , ) * ) => { ... };
}

Create an iterator running multiple iterators in lockstep.

The izip! iterator yields elements until any subiterator returns None.

This is a version of the standard .zip() that's supporting more than two iterators. The iterator elment type is a tuple with one element from each of the input iterators. Just like .zip(), the iteration stops when the shortest of the inputs reaches its end.

Note: The result of this macro is an iterator composed of repeated .zip() and a .map(); it has an anonymous type. Prefer this macro izip!() over multizip for the performance benefits of using the standard library .zip().

#[macro_use] extern crate itertools;

// iterate over three sequences side-by-side
let mut results = [0, 0, 0, 0];
let inputs = [3, 7, 9, 6];

for (r, index, input) in izip!(&mut results, 0..10, &inputs) {
    *r = index * 10 + input;
}

assert_eq!(results, [0 + 3, 10 + 7, 29, 36]);

Note: To enable the macros in this crate, use the #[macro_use] attribute when importing the crate:

#[macro_use] extern crate itertools;