Struct chumsky::error::Simple

pub struct Simple<I: Hash, S = Range<usize>> { /* private fields */ }

A simple default error type that tracks error spans, expected inputs, and the actual input found at an error site.

Please note that it uses a HashSet to remember expected symbols. If you find this to be too slow, you can implement Error for your own error type or use Cheap instead.

Implementations

impl<I: Hash + Eq, S: Clone> Simple<I, S>

pub fn custom<M: ToString>(span: S, msg: M) -> Self

Create an error with a custom error message.

pub fn span(&self) -> S

Returns the span that the error occured at.

pub fn expected(&self) -> impl ExactSizeIterator<Item = &Option<I>> + '_

Returns an iterator over possible expected patterns.

pub fn found(&self) -> Option<&I>

Returns the input, if any, that was found instead of an expected pattern.

pub fn reason(&self) -> &SimpleReason<I, S>

Returns the reason for the error.

pub fn label(&self) -> Option<&'static str>

Returns the error’s label, if any.

pub fn map<U: Hash + Eq, F: FnMut(I) -> U>(self, f: F) -> Simple<U, S>

Map the error’s inputs using the given function.

This can be used to unify the errors between parsing stages that operate upon two forms of input (for example, the initial lexing stage and the parsing stage in most compilers).

Trait Implementations

impl<I: Clone + Hash, S: Clone> Clone for Simple<I, S>

fn clone(&self) -> Simple<I, S>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<I: Debug + Hash, S: Debug> Debug for Simple<I, S>

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

Formats the value using the given formatter.

impl<I: Display + Hash, S: Span> Display for Simple<I, S>

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

Formats the value using the given formatter.

impl<I: Debug + Display + Hash, S: Span + Display + Debug> Error for Simple<I, S>

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

The lower-level source of this error, if any.

fn backtrace(&self) -> Option<&Backtrace>

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

Returns a stack backtrace, if available, of where this error occurred.

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

impl<I: Hash + Eq, S: Span + Clone + Debug> Error<I> for Simple<I, S>

type Span = S

The type of spans to be used in the error.

type Label = &'static str

The label used to describe a syntatic structure currently being parsed.

fn expected_input_found<Iter: IntoIterator<Item = Option<I>>>(
    span: Self::Span,
    expected: Iter,
    found: Option<I>
) -> Self

Create a new error describing a conflict between expected inputs and that which was actually found.

fn unclosed_delimiter(
    unclosed_span: Self::Span,
    delimiter: I,
    span: Self::Span,
    expected: I,
    found: Option<I>
) -> Self

Create a new error describing a delimiter that was not correctly closed.

fn with_label(self, label: Self::Label) -> Self

Indicate that the error occured while parsing a particular syntactic structure.

fn merge(self, other: Self) -> Self

Merge two errors that point to the same input together, combining their information.

impl<I: Hash + PartialEq, S: PartialEq> PartialEq<Simple<I, S>> for Simple<I, S>

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.