Enum LexError 

pub enum LexError {
    UnexpectedCharacters {
        char_pos: usize,
        line: usize,
        column: usize,
        ch: char,
        allowed: Vec<String>,
    },
    Callback {
        message: String,
    },
    InputTooLarge {
        byte_len: usize,
    },
    WrongContextToken {
        token: Token,
        allowed: Vec<String>,
    },
}

Runtime lex errors. Construction-time problems are LexerBuildError.

Variants

UnexpectedCharacters

No terminal matches. allowed is scanner terminals − ignore_types, sorted, with Lark’s literal empty-set fallback string (END_OF_FILE).

Fields

char_pos: usize

Code-point offset (Lark’s lex_pos).

line: usize

column: usize

ch: char

The offending character (UnexpectedCharacters.char).

allowed: Vec<String>

Callback

A user callback failed (binding-raised); carries its message.

Fields

message: String

InputTooLarge

Input longer than the u32 position ceiling can represent (byte length > u32::MAX). The byte length is an upper bound on the code-point count, so this single entry guard makes every downstream char_pos as u32 cast provably safe (u32 positions).

Fields

byte_len: usize

WrongContextToken

Contextual-lexer root fallback: the character is a valid terminal, just not in this parser state — the root lexer lexed token, and allowed is the original per-state error’s set. The parse path surfaces this as UnexpectedToken (exception class parity is the v1 gate).

Fields

token: Token

allowed: Vec<String>

Trait Implementations

impl Clone for LexError

fn clone(&self) -> LexError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for LexError

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

Formats the value using the given formatter.

impl Display for LexError

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

Formats the value using the given formatter.

impl Eq for LexError

impl Error for LexError

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 PartialEq for LexError

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for LexError