Enum LexerBuildError 

pub enum LexerBuildError {
    Uncompilable {
        terminal: String,
        reason: String,
    },
    ZeroWidth {
        terminal: String,
    },
    UnknownIgnore {
        name: String,
    },
    UnsupportedGlobalFlags {
        flags: u32,
    },
    DivergentConstruct {
        terminal: String,
        construct: String,
        at: usize,
        reason: String,
        pattern: String,
        hint: Option<String>,
    },
}

Construction-time errors, mirroring Lark’s validation, all gated by skip_validation.

Variants

Uncompilable

Neither engine compiles the terminal.

Fields

terminal: String

reason: String

ZeroWidth

The terminal can match the empty string.

Fields

terminal: String

UnknownIgnore

%ignore names a terminal that does not exist.

Fields

name: String

UnsupportedGlobalFlags

Unsupported g_regex_flags bits (surfaced from the scanner build).

Fields

flags: u32

DivergentConstruct

A terminal uses a Python-re construct whose Rust-engine semantics differ, and it was neither suppressed by flag context nor rewritten (translation off, or an untranslatable exotic). Enable LexerConf::translate_python_regex to rewrite the mechanical set (user decision 2026-07-07; see [crate::py_regex]). Lark itself never raises this — it runs on CPython re directly — so there is no Lark parity to preserve; hyperlark refuses what it cannot match Python-exactly.

Fields

terminal: String

construct: String

Human name of the divergent construct (e.g. $, \Z).

at: usize

Byte offset of the construct in the terminal’s to_regexp() output.

reason: String

Why it is refused — specific to the construct, and names the dialect (Python re, the regex module) the prefix no longer states.

pattern: String

A window of the pattern around at. The terminal named above may only REFER to the one the construct was written in, so the text is what makes it findable.

hint: Option<String>

The LexerConf flag that would rewrite the mechanical set, when one would; None for constructs no flag can fix.

Trait Implementations

impl Clone for LexerBuildError

fn clone(&self) -> LexerBuildError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for LexerBuildError

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

Formats the value using the given formatter.

impl Display for LexerBuildError

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

Formats the value using the given formatter.

impl Eq for LexerBuildError

impl Error for LexerBuildError

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 LexerBuildError

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for LexerBuildError