pub fn ez_eval(
ns: &mut impl EvalNamespace
) -> Result<f64, Error>
ez_eval() function provides a very simple way to perform expression evaluation with just one function call.
If you only need to evaluate an expression one time, then
probably be perfectly adequate. But if you plan to evaluate the same
expression many times, or if you plan to evaluate many expressions, you
are able to achieve better performance by allocating a single
using it to perform multiple parse-compile-eval cycles yourself.
If there are any
Errors during the parse-eval process, they will be returned.