How can I split a string (String or &str) on more than one delimiter?

Question

I want to be able to separate the string aabbaacaaaccaaa on the strings bb and cc but not on b or c. The example would result in aa,aacaaa,aaa.

I already can split a string on a single delimiter, and the words() function splits a string on ,\n and \t, so I figured it must be possible.

Answer 1

Unfortunately, you can't do this with the standard library right now. You can split on multiple char delimiters though, as words does. You need to give a slice of characters to split:

for part in "a,bc;d".split(&[',', ';'][..]) {
    println!(">{}<", part);
}

If you try with strings, however:

for part in "a,bc;d".split(&[",", ";"][..]) {
    println!(">{}<", part);
}

You'll get the error:

error[E0277]: expected a `Fn<(char,)>` closure, found `[&str]`
 --> src/main.rs:2:32
  |
2 |     for part in "a,bc;d".split(&[",", ";"][..]) {
  |                                ^^^^^^^^^^^^^^^ expected an `Fn<(char,)>` closure, found `[&str]`
  |
  = help: the trait `Fn<(char,)>` is not implemented for `[&str]`
  = note: required because of the requirements on the impl of `FnOnce<(char,)>` for `&[&str]`
  = note: required because of the requirements on the impl of `Pattern<'_>` for `&[&str]`

In nightly Rust, you could implement Pattern for your own type that includes a slice of strings.

If you are cool with using a well-supported crate that isn't part of the standard library, you can use regex:

use regex; // 1.4.5

fn main() {
    let re = regex::Regex::new(r"bb|cc").unwrap();
    for part in re.split("aabbaacaaaccaaa") {
        println!(">{}<", part);
    }
}