Function run_sexp_query 

pub fn run_sexp_query(
    file: &Path,
    content: &str,
    query_str: &str,
    grammar: &Language,
    grammar_name: &str,
) -> Result<Vec<MatchResult>, String>

Run a tree-sitter S-expression query against a single file’s content.

Returns one MatchResult per capture per match.