Enum ParserError 

pub enum ParserError {
    SyntaxError,
    TooManyErrors,
    Irrecoverable,
    ExtraSymbol,
    UnexpectedEOS,
    UnexpectedError,
    EncounteredErrors,
    AbortRequest,
}

Code of the error that occurred during the parsing, returned by the parse_stream(…) method of the parser.

Variants

SyntaxError

A syntax error was met. Either

• The next terminal of the parsed text doesn’t match the expected one in the current rule alternative; for example, a rule assign -> "let" Id "=" expr ";"; has just successfully scanned the terminal "let", but the next one isn’t Id.
• The next symbol doesn’t correspond to any correct option for the next nonterminal ( in other words, there is no entry in the parsing table for that combination). For example, in the same rule as above, the terminal "=" has just been scanned successfully, but expr doesn’t begin with the next one.

This error is returned only when the parser doesn’t try to recover from syntax errors; this option is set with the set_try_recover(…) method and is enabled by default.

See also ParserError::TooManyErrors.

TooManyErrors

Too many syntax errors were met, either

• during the parsing. The limit is set by the constant Parser::MAX_NBR_RECOVERS.
• by the lexer. The limit is set by the constant Parser::MAX_NBR_LEXER_ERRORS.

This error is returned only when the parser tries to recover from syntactic or lexical errors; this option is set with the set_try_recover(…) method and is enabled by default.

See also ParserError::SyntaxError.

Irrecoverable

The parser has reached an irrecoverable error, after trying to recover from a syntax error and encountering the end of the text.

ExtraSymbol

The parser has reached the end of the top rule, but there are still terminals coming from the lexer.

Note that if the text is expected to contain something else after the part that must be parsed, it is possible to tell the parser to conclude the parsing without looking any further. This can be done in the listener with the [check_abort_request(…)] performed regularly by the parser. See the [examples/terminate] parser to see how it can be used.

UnexpectedEOS

The parser has encountered the end of the text, but the top rule hasn’t been fully parsed.

UnexpectedError

This is an internal error that isn’t supposed to happen.

EncounteredErrors

The text has been fully parsed, but syntax errors were encountered by the parser (and could be recovered from).

See also ParserError::SyntaxError.

AbortRequest

An Abort was returned by the [check_abort_request(…)] method of the listener.

Trait Implementations

impl Debug for ParserError

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

Formats the value using the given formatter.

impl Display for ParserError

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

Formats the value using the given formatter.

impl PartialEq for ParserError

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for ParserError