/// <summary>
/// Transform formula to canonical form.
/// </summary>
/// <param name="formula"></param>
/// <returns></returns>
/// <exception cref="InvalidFormulaException"><see cref="IExpressionSearcher"/> cannot form groups collection or render groups that were found.</exception>
public string Transform(string formula, bool optimize = true)
{
if (optimize && _groupsSearcher is IFormulaValidator validator && !validator.Validate(formula))
{
// it is faster than catch exception.
return(null);
}
var groups = _groupsSearcher.SearchGroups(formula)
?? throw new InvalidFormulaException(formula, "cannot find variable's expressions");
return(_renderer.Render(groups) ?? throw new InvalidFormulaException(formula, "cannot render formula"));
}
public void NullString_ThrowsInvalidFormulaException()
{
Assert.Throws <InvalidFormulaException>(() => searcher.SearchGroups(null).ToArray());
}