pub fn apply_formulas(
sources: &[Arc<dyn DataSource>],
definitions: &[FormulaDefinition],
) -> (Vec<Arc<dyn DataSource>>, Vec<String>)Expand description
Attach formulas to opened datasets.
Formulas with any unqualified reference are applied per dataset; formulas
whose references are all NAME[n] belong only to the first referenced
dataset so a multi-file collection does not show the same field twice.
Returns the wrapped sources and one message per formula that no dataset
could evaluate.