Splitting array into variables


I’m reading lines from a file. Each line looks like this 1 2 3 4 5 6\n and I want each value assigned to a variable like this: x = 1, y = 2, z = 3 and so on. They need to be converted to i32, so I could easily operate with them.

To rephrase in a programming language, here’s an example in Python:

x, y, z, a, b, c = map(int, '1 2 3 4 5 6\n'.split())

So far here’s what I came up with in Rust:

let split_line: Vec<&str> = "1 2 3 4 5 6\n".trim().split(" ").collect();
let x: i32 = split_line[0].parse().unwrap();
let y: i32 = split_line[1].parse().unwrap();
let z: i32 = split_line[2].parse().unwrap();
let a: i32 = split_line[3].parse().unwrap();
let b: i32 = split_line[4].parse().unwrap();
let c: i32 = split_line[5].parse().unwrap();

Is there any way of making this more concise (preferably without writing a macro, which I am aware is possible, but which would make it longer and more obscure)?


not in stable rust. Any reason why they need to be their own variables? Would the following solve your issue, since you’d then have a vector of i32?

let v: Vec<i32> = "1 2 3 4 5 6\n"
    .split(" ")
    .map(|val| val.parse().unwrap())

if you then need them as their own variable, you can destructure a temporary tuple

let (x, y, z, a, b, c) = (v[0], v[1], v[2], v[3], v[4], v[5]);


Thanks @oli_obk. I haven’t thought of destructuring a temporary tuple, I still hoped there would be something similar to to_tuple (although I couldn’t find it in docs). I wonder if a method like this would make sense or be useful to others.

Regarding the variables vs array indices – I store them in their own variables for readability reasons mostly. In reality they’re not actually x, y, z etc. but rather variables with longer meaningful names.

Edit: I also thought that since "1".parse().unwrap() automatically determines the type to parse into (i32 in this case), then it would be possible to have x, y, z, a, b, c with different types (e.g. x: i32, y: f64 etc.), however this doesn’t work:

let (x: i32, y: i64) = (1, 2);


Yea, without macros you are not going to get this code more readable.

You can still define a tuple with multiple types, but if you have long names and expressions, the one let statement per line method is much more readable.

let (x, y): (i32, i64) = (1, 2);