Function lower_grammar 

pub fn lower_grammar(
    grammar: &Grammar,
    format: &str,
    options: &GrammarLoweringOptions<'_>,
) -> Result<GrammarLowering, GrammarLoweringError>

Lowers grammar into format.

The result holds the lowered grammar, the executable text the target emitter writes for it, the steps and the metadata links that reconstruct the original from the executable, and whether every encoding is exact. The options’ emit and import replace the format’s own pair.

Errors

Returns a GrammarLoweringError for an unsupported format, a grammar without a start rule, a character set the format cannot spell, or an emitter or importer error.