7 releases
0.3.0 | Oct 18, 2023 |
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0.2.3 | Oct 7, 2023 |
0.1.1 | Oct 3, 2023 |
#217 in Value formatting
Used in finra-rs
18KB
317 lines
join-string
A simple crate to join elements as a string, interspersing a separator between all elements.
This is done somewhat efficiently, if possible, meaning if the iterator is cheaply
clonable you can directly print the result of Join::join()
without creating a temporary
String
in memory. The Join::join()
method will appear on anything that implements
std::iter::IntoIterator
,
meaning on all iterators and collections. The elements and the separator need to implement
std::fmt::Display
. Alternatively
the Join::join_str()
method can be used to join elements that only implement
AsRef<str>
.
Examples
use join_string::Join;
assert_eq!(
"foo bar baz".split_whitespace().join(", ").into_string(),
"foo, bar, baz");
println!("{}",
"foo bar baz".split_whitespace()
.map(|s| s.chars().rev().join(""))
.join(' '));
// Output: oof rab zab
You can also write the result more directly to a
std::io::Write
or
std::fmt::Write
even if the backing iterator doesn't implement
Clone
.
use join_string::Join;
["foo", "bar", "baz"].join(", ").write_io(std::io::stdout())?;
let mut str = String::new();
["foo", "bar", "baz"].join(", ").write_fmt(&mut str)?;
Notes
The standard library already provides a similar
std::slice::Join
trait on slices, but not on iterators, and the standard library version always directly returns a
new String
. Further there are multiple other similar crates that however work a bit differently,
e.g. having more restrictions on element and separator types or always returning a String
.