Trait UnescapeExt

pub trait UnescapeExt: Sealed {
    // Required methods
    fn to_unescaped(&self) -> Result<Cow<'_, str>, InvalidEscape>;
    fn to_unescaped_with(
        &self,
        callback: impl EscapeHandler,
    ) -> Result<Cow<'_, str>, InvalidEscape>;
}

An extension trait for &str to allow parsing escape sequences in strings, only copying when needed.

Required Methods

fn to_unescaped(&self) -> Result<Cow<'_, str>, InvalidEscape>

Unescapes a string, returning an alloc::borrow::Cow. Will only allocate if the string has any escape sequences.

Uses crate::DefaultHandler.

Errors

Errors if there’s an invalid escape sequence in the string. Passes back the byte index of the invalid character.

Examples

Parsing an escaped string

let escaped = "Hello,\\nworld!".to_unescaped();
assert_eq!(
    escaped.unwrap(),
    Cow::Owned::<'_, str>("Hello,\nworld!".to_string())
);

Not allocating for a string without escapes

let no_escapes = "No escapes here!".to_unescaped();
assert_eq!(
    no_escapes.unwrap(),
    Cow::Borrowed("No escapes here!")
);

Erroring for invalid escapes

//                            v  invalid at index 7
let invalid_escape = r"Uh oh! \xJJ".to_unescaped();
assert_eq!(
    invalid_escape.unwrap_err().index,
    7
);

fn to_unescaped_with( &self, callback: impl EscapeHandler, ) -> Result<Cow<'_, str>, InvalidEscape>

Unescapes a string using a custom escape handler. See the documentation of crate::EscapeHandler for more details.

Errors

Errors if there’s an invalid escape sequence in the string. Passes back the byte index of the invalid character.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl UnescapeExt for str

fn to_unescaped(&self) -> Result<Cow<'_, str>, InvalidEscape>

fn to_unescaped_with( &self, callback: impl EscapeHandler, ) -> Result<Cow<'_, str>, InvalidEscape>

Implementors