# XO0152: rune literal that is empty, unterminated, or holds more than one character

A rune literal is exactly one character (or one escape) between single quotes: `'a'`, `'\n'`, `'\u{1F600}'`. `''`, `'ab'`, and an unclosed `'a` are rejected. Text of several characters is a `Str` and uses double quotes. See core 1.6.

## Example

```xo
fn f() -> Str {
  let s = 'ab'
  "${s}"
}
```

## Fix

```xo
fn f() -> Str {
  let s = "ab"
  s
}
```

Run `xo explain XO0152` for this text in a terminal, or see
[section 10.6 of the specification](../../spec/core/#106-diagnostic-codes).