Struct ParseError 

pub struct ParseError {
    pub message: String,
    pub span: Span,
    pub line: usize,
    pub col: usize,
}

Why a source did not parse, and where.

Structured, and located at the boundary. message says what was expected and what was found, in blue’s own words; span is the byte range of the offending text; line and col are that range’s start, 1-based, with the column counted in characters. Every public entry point fills line/col from the source it was given, so Display reads 3:7: expected ), found ]`` and never a byte offset.

The byte offsets used to BE the display (… at 10..11), and a Rust Debug rendering named the token (found Ident("y")). Both are facts about the implementation; neither is something an author can act on. The span stays, as data, for any consumer that needs to point into the buffer — an editor squiggle, a diagnostic code attached downstream.

Fields

message: String

span: Span

line: usize

1-based line of span.start.

col: usize

1-based column of span.start, in characters.

Trait Implementations

impl Clone for ParseError

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 ParseError

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

Formats the value using the given formatter.

impl Display for ParseError

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

Formats the value using the given formatter.

impl Error for ParseError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<LexError> for ParseError

fn from(e: LexError) -> Self

Converts to this type from the input type.

impl PartialEq for ParseError

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for ParseError