Function parse_with_macros 

pub fn parse_with_macros(
    source: &str,
    macros: &MacroSet,
) -> Result<Node, MathError>

parse, against a macro set (a preamble pack and/or caller definitions): calls expand at the token level before the grammar runs, with body-produced tokens carrying their call site’s span (see macros).

Errors

As parse, plus the macro-expansion errors (macros): recursion refusal, budget overruns, malformed definitions — every one precise.