try_all

Rust iterator extensions to operate on Results effectively.

try_map_all

and, for now, its friend try_map_all_opt

Applies a closure on all items of the iterator until one fails (or all succeed).

Arguments:

• f: fallible mapping function

Returns: The iterator of all successes, or the first failure.

Examples

Useful for propagating failures from within closures with ? operator:

fn parse_all_numbers(strs: &Vec<&str>) -> Result<Vec<u64>, std::num::ParseIntError> {
	Ok(strs.iter().try_map_all(|s| s.parse())?.collect())
}

or for Options:

fn not_zero(is: Vec<u64>) -> Option<Vec<u64>> {
	Some(is.iter().try_map_all_opt(|i| if i > 0 { Some(i) } else { None })?.collect())
}

try_all

Ensures that all items of the iterator are Ok, otherwise returns the first failure.

Returns: The iterator of all successes, or the first failure.

Examples:

Useful for propagating failures from within closures with ? operator

fn parse_all_numbers(strs: &Vec<&str>) -> Result<Vec<u64>, std::num::ParseIntError> {
	Ok(strs.iter().map(|s| s.parse()).try_all()?.collect())
}