pub fn import_bnf(text: &str) -> Result<Grammar, GrammarImportError>Expand description
Parses classic angle-bracket Backus-Naur Form text into the grammar IR.
Each line holds one <name> ::= alternatives production; a later
production for the same name adds alternatives to it. Terminals are single-
or double-quoted without escape sequences, and ; starts a line comment.
ยงErrors
Returns GrammarImportError when the BNF text cannot be parsed or when
a non-terminal reference does not resolve to a rule.