pub fn import_antlr(text: &str) -> Result<Grammar, GrammarImportError>Expand description
Parses ANTLR v4 .g4 grammar text into the grammar IR.
The importer is a clean-room parser for the structural ANTLR grammar subset
needed by the grammar IR. ANTLR alternatives are lowered as unordered CFG
choices, while lexer commands and dropped target-language actions are
preserved in rule documentation; -> skip and -> channel(NAME) also put
the rule on that channel, which makes it trivia. EOF is the end of the
input, and character sets read \uXXXX, \u{X...} and \p{NAME} for a
general category or script.
ยงErrors
Returns GrammarImportError when the source cannot be parsed as the
supported ANTLR subset or when a parsed prelude construct is recognized but
not yet representable.