Enum EarleyLexerSource 

pub enum EarleyLexerSource<'a> {
    Basic(&'a BasicLexer),
    Dynamic {
        matchers: &'a DynamicMatchers,
        ignore: &'a [String],
    },
    DynamicComplete {
        matchers: &'a DynamicMatchers,
        ignore: &'a [String],
    },
    Custom(&'a Mutex<dyn TokenSource + Send + 'a>),
}

Which scan strategy drives an Earley parse (Lark’s resolved lexer; the frontends facade’s ResolvedLexer). Earley defines its own source enum rather than importing LALR’s LexerSource (engine boundary): the basic path takes a pre-lexing BasicLexer token stream; the dynamic paths take the construction-built matchers.

Variants

Basic(&'a BasicLexer)

Basic-lexer Earley. Under a postlex the token stream is wrapped by the engine-agnostic connector.

Dynamic

Dynamic-lexer Earley (xearley): per-terminal forward regex; forbids postlex + lexer_callbacks (enforced at the frontend). The per-terminal DynamicMatchers are built once at construction (build_dynamic_matchers, where a zero-width/bad regexp already raised the GrammarError) and borrowed here — the parse never compiles a matcher.

Fields

matchers: &'a DynamicMatchers

ignore: &'a [String]

DynamicComplete

dynamic_complete: dynamic + shorter-prefix enumeration.

Fields

matchers: &'a DynamicMatchers

ignore: &'a [String]

Custom(&'a Mutex<dyn TokenSource + Send + 'a>)

A caller-implemented crate::custom::TokenSource feeding the basic scan (Lark: a lexer class bypasses the parser×lexer matrix and Earley drives it through _match_earley_basic; the [custom_old0,earley]/[custom_old1,earley] Lark cells). Pulled lazily, one token per recognizer step, with the live pre-closure expects snapshot handed to each pull ([CustomScan]). Postlex composes on top, as for Basic. An unknown type name stalls the recognizer at that token — Lark’s name-mismatch — and the stall reports the raw name (UnexpectedToken('WAT')).