Function caldyn::eval

pub fn eval<'a, C>(input: &str, context: C) -> Result<f64, Error> where
    C: Into<Option<&'a Context<'a>>>, 

Evaluate a single expression from input.

Returns Ok(result) if the evaluation is successful, or Err(cause) if parsing or evaluating the expression failed.

Example

use caldyn::{eval, Context};

assert_eq!(eval("45 - 2^3", None), Ok(37.0));

let mut context = Context::new();
context.set("a", -5.0);
assert_eq!(eval("3 * a", &context), Ok(-15.0));