Function eval_number_with_context 

pub fn eval_number_with_context<C: Context>(
    string: &str,
    context: &C,
) -> EvalexprResult<FloatType>

Evaluate the given expression string into a float with the given context. If the result of the expression is an integer, it is silently converted into a float.

See the crate doc for more examples and explanations of the expression format.