meval
pub struct CustomFunc<S, T>(pub S, pub T);
A custom function of one variable.
impl<S: AsRef<str>, T: Fn(f64) -> f64> Context for CustomFunc<S, T>
fn eval_func(&self, name: &str, args: &[f64]) -> Result<f64, FuncEvalError>
fn get_var(&self, _: &str) -> Option<f64>