Macro str_split

macro_rules! str_split {
    ($string:expr, $splitter:expr $(,)?) => { ... };
}

Splits $string (a &'static str constant) with $splitter, returning an array of &'static strs.

Alternatives

For an alternative macro which will be usable in slice patterns (once inline_const_pat is stabilized) you can use str_split_pat.

Signature

This macro acts like a function of this signature:

fn str_split(string: &'static str, splitter: impl Splitter) -> [&'static str; LEN]

and is evaluated at compile-time.

impl Splitter is any of these types:

• &'static str

• char

• u8: only ascii values (0 up to 127 inclusive) are allowed

The value of LEN depends on the string and splitter arguments.

Example

use const_format::str_split;

assert_eq!(str_split!("this is nice", ' '), ["this", "is", "nice"]);

assert_eq!(str_split!("Hello, world!", ", "), ["Hello", "world!"]);

// A `""` splitter outputs all chars individually (`str::split` does the same)
assert_eq!(str_split!("🧡BAR🧠", ""), ["", "🧡", "B", "A", "R", "🧠", ""]);

// Splitting the string with an ascii byte
assert_eq!(str_split!("dash-separated-string", b'-'), ["dash", "separated", "string"]);

{
    const STR: &str = "foo bar baz";
    const SPLITTER: &str = " ";

    // both arguments to the `str_aplit` macro can be non-literal constants
    const SPLIT: [&str; 3] = str_split!(STR, SPLITTER);

    assert_eq!(SPLIT, ["foo", "bar", "baz"]);
}