Struct LineParser 

pub struct LineParser { /* private fields */ }

Stateful parser for turning arbitrary byte chunks into lines.

Drive it by calling Self::next_line in a loop with a slice cursor that you advance across calls; on EOF call Self::finish once to flush any unterminated trailing line. On a stream gap (chunks dropped between deliveries) call Self::on_gap to discard the in-progress partial line and resynchronize at the next newline.

Implementations

impl LineParser

pub fn new() -> Self

Creates a new parser in ReadingLine mode with empty buffers.

pub fn on_gap(&mut self)

Notifies the parser that the upstream delivery dropped chunks. Discards any partial line in progress and resynchronizes at the next newline instead of joining bytes across the gap.

pub fn next_line<'a, 'b>( &'a mut self, chunk: &mut &'b [u8], options: LineParsingOptions, ) -> Option<Cow<'a, str>>

where 'b: 'a,

Advances through chunk and yields the next parsed line, if any.

chunk is mutated in place to advance past the consumed prefix. Call repeatedly, reusing the same slice cursor, until this returns None; at that point the chunk is exhausted and any partial line is buffered for the next chunk.

The returned Cow borrows from the chunk slice when the line fits entirely in this call and no partial line was already buffered (zero-allocation fast path), and borrows from the parser’s internal emitted-line slot otherwise. Either way, drop the Cow before the next call — the borrow checker enforces this through the &'a mut self signature.

pub fn finish(&mut self) -> Option<Cow<'_, str>>

Flushes any unterminated trailing line at EOF.

Returns None when there is nothing to flush — the buffer is empty, or the parser is in DiscardUntilNewline mode (a gap or overflow truncation is still draining and the buffered remainder is conservatively dropped). Otherwise returns the buffered line as a Cow borrowing from the parser’s emitted-line slot.

Trait Implementations

impl Default for LineParser

fn default() -> Self

Returns the “default value” for a type.