iter-python

Python generator expressions ([iter!]) and "list" comprehensions ([vec_it!])

Usage

1. Add the following line to your Cargo.toml, under [dependencies]:

   toml iter-python = "0.9.2"

2. Bring [iter!] and [(enhanced) vec!][vec_it!] into scope in you Rust code with:

   rust use ::iter_python::{*, vec_it as vec};

Example

``rust //! Run withcargo run --example readme`

use ::iterpython::{*, iter, // "generator expressions" vecit as vec, // "list comprehensions" };

fn main () { let v = vec![ 2 * x for &xopt in &[None, Some(21), None] if let Some(x) = xopt ]; assert_eq!( dbg!(v), vec![42], // classic vec! macro is still there );

let is_square = |n: u32| n == ((n as f64).sqrt().trunc() as u32).pow(2);
let odds = || iter!(2 * n + 1 for n in 0 ..);
let sums_of_odds = iter!(odds().take(n).sum() for n in 1 ..);
assert!(sums_of_odds.take(100).all(is_square));

const N: usize = 6;
let line = format!("+-{}-+", "-+-".join(iter!("---" for _ in 1 .. N)));
// And the following allocates only one `String`:
let matrix = format!(
    "{line}\n{body}\n{line}\n",
    line=line,
    body="\n".join(iter!(
        f!(
            "| {row} |",
            row=" | ".join(iter!(
                f!("a{i}{j}", i=i, j=j)
                for j in 1 .. N
            )),
        ) for i in 1 .. N
    )),
);
println!("{}", matrix);
assert_eq!(matrix, concat!(
    "+-----+-----+-----+-----+-----+\n",
    "| a11 | a12 | a13 | a14 | a15 |\n",
    "| a21 | a22 | a23 | a24 | a25 |\n",
    "| a31 | a32 | a33 | a34 | a35 |\n",
    "| a41 | a42 | a43 | a44 | a45 |\n",
    "| a51 | a52 | a53 | a54 | a55 |\n",
    "+-----+-----+-----+-----+-----+\n",
));

} ```

See [iter!] and [vec_it!] for more examples.