Struct LexerConf 

pub struct LexerConf {
    pub terminals: Vec<TerminalDef>,
    pub ignore: Vec<String>,
    pub g_regex_flags: u32,
    pub callbacks: HashMap<String, TokenCallback>,
    pub translate_python_regex: bool,
    pub optimize_terminals: bool,
    pub scanner_engine: ScannerEngine,
    /* private fields */
}

Everything BasicLexer::new consumes — never global state, so one is built per accept-set from a filtered conf. always_accept is deliberately absent: it is a ContextualLexer-only param whose effect arrives pre-folded into the terminal subset. Clone (callbacks are Arc-shared) — a custom-lexer instance retains a copy for the source to build from, Lark’s lexer_type(lexer_conf) handoff.

Fields

terminals: Vec<TerminalDef>

Loader-preserved order — TokenIds are indices into this list.

ignore: Vec<String>

%ignore terminal names.

g_regex_flags: u32

Python re flag bitmask, applied at engine-compile time only.

callbacks: HashMap<String, TokenCallback>

Per-terminal user callbacks by terminal name; drives the gated CallChain.

translate_python_regex: bool

Rewrite Python-re constructs whose semantics differ under the Rust engines ($, \Z, octal escapes, …) to exact Python semantics instead of raising at build (see [crate::py_regex]). Off by default, and experimental: hyperlark refuses what it cannot match Python-exactly.

optimize_terminals: bool

Rewrite terminals whose exact Lark pattern has a verified lookaround-free equivalent to that equivalent, keeping them on the regex-automata fast path. Applied as a real early TerminalDef rewrite — metadata, sort keys, and the engine all see the substitute. The core default is on; the conformance runner threads it off so parity comparisons exercise the true Lark-dialect patterns.

scanner_engine: ScannerEngine

Which regex-automata engine drives the fast (look-around-free) scanner partition. Provisional knob overlaid from LarkOptions::scanner_engine; inherited unchanged by every per-state contextual sub-conf. Default [ScannerEngine::Lazy].

Trait Implementations

impl Clone for LexerConf

fn clone(&self) -> LexerConf

Returns a duplicate of the value.

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

Performs copy-assignment from source.