Struct Utf8Decoder 

pub struct Utf8Decoder { /* private fields */ }

Decodes Event::Text bytes into str pieces, across chunk boundaries.

Event::Text is raw bytes, because the parser never copies them. A consumer that wants characters needs two things this handles: a multi-byte character split across two feed_with calls, and invalid bytes, which become U+FFFD exactly as Parser::feed renders them.

Pieces are borrowed: an ASCII run is handed over as one slice of the input with nothing copied, and only a character straddling a boundary is assembled in the decoder’s own four bytes. It allocates nothing, ever.

let mut parser = Parser::new();
let mut decoder = Utf8Decoder::new();
let mut seen = String::new();
// The 'é' is split across the two chunks.
for chunk in [&b"caf\xC3"[..], &b"\xA9!"[..]] {
    parser.feed_with(chunk, |event| match event {
        Event::Text(bytes) => decoder.decode(bytes, |s| seen.push_str(s)),
        _ => decoder.flush_incomplete(|s| seen.push_str(s)),
    });
}
assert_eq!(seen, "café!");

Implementations

impl Utf8Decoder

pub fn new() -> Self

A decoder with nothing held over.

pub fn is_idle(&self) -> bool

True when no partial character is held over from a previous chunk. Then a run of ASCII bytes decodes to itself, and a caller may use it directly without going through Utf8Decoder::decode.

pub fn decode<F: FnMut(&str)>(&mut self, bytes: &[u8], f: F)

Decode bytes, calling f with each piece of text in order.

A character left incomplete at the end is held for the next call.

pub fn flush_incomplete<F: FnMut(&str)>(&mut self, f: F)

Give up on a character left incomplete, emitting U+FFFD for it.

Call this when something other than text arrives — a control byte or an escape sequence ends a text run, and the held bytes can never be completed. Does nothing when no character is pending.

pub fn is_pending(&self) -> bool

True when a partial character is held for the next decode.

Trait Implementations

impl Clone for Utf8Decoder

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Utf8Decoder

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Utf8Decoder

fn default() -> Self

Returns the “default value” for a type.