Enum antlr_rust::errors::ANTLRError

pub enum ANTLRError {
    LexerNoAltError {
        start_index: isize,
    },
    NoAltError(NoViableAltError),
    InputMismatchError(InputMisMatchError),
    PredicateError(FailedPredicateError),
    IllegalStateError(String),
    FallThrough(Box<dyn Error>),
    OtherError(Box<dyn Error>),
}

Main ANTLR4 Rust runtime error

Variants

LexerNoAltError

Returned from Lexer when it fails to find matching token type for current input

Usually Lexers contain rule that captures all invalid tokens like:

ERROR_TOKEN: . ;

to prevent lexer from throwing errors and have all error handling in parser.

Fields of LexerNoAltError

start_index: isize

NoAltError(NoViableAltError)

Indicates that the parser could not decide which of two or more paths to take based upon the remaining input. It tracks the starting token of the offending input and also knows where the parser was in the various paths when the error. Reported by reportNoViableAlternative()

InputMismatchError(InputMisMatchError)

This signifies any kind of mismatched input exceptions such as when the current input does not match the expected token.

PredicateError(FailedPredicateError)

A semantic predicate failed during validation. Validation of predicates occurs when normally parsing the alternative just like matching a token. Disambiguating predicate evaluation occurs when we test a predicate during prediction.

IllegalStateError(String)

Internal error.

FallThrough(Box<dyn Error>)

Indicates that error should not be processed and parser should immediately return to caller

OtherError(Box<dyn Error>)

Used to allow user to emit his own errors from parser actions or from custom error strategy

Trait Implementations

impl Clone for ANTLRError

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ANTLRError

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

Formats the value using the given formatter.

impl Display for ANTLRError

fn fmt(&self, _f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl Error for ANTLRError

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 1.41.0:

use the Display impl or to_string()

if let Err(e) = "xc".parse::<u32>() { // Print e itself, no need for description(). eprintln!("Error: {}", e); }

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

Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

impl RecognitionError for ANTLRError

fn get_offending_token(&self) -> Option<&dyn Token>

fn get_message(&self) -> String