Struct evalexpr::Function

pub struct Function { /* fields omitted */ }

A user-defined function. Functions can be used in expressions by storing them in a Context.

Examples

use evalexpr::*;

let mut context = HashMapContext::new();
context.set_function("id".into(), Function::new(Box::new(|argument| {
    Ok(argument.clone())
}))).unwrap(); // Do proper error handling here
assert_eq!(eval_with_context("id(4)", &context), Ok(Value::from(4)));

Methods

impl Function

pub fn new(function: Box<dyn Fn(&Value) -> EvalexprResult<Value>>) -> Self

Creates a user-defined function.

The function is a boxed function that takes a Value and returns a EvalexprResult<Value, Error>.

Trait Implementations

impl Debug for Function

fn fmt(&self, f: &mut Formatter) -> Result<(), Error>

Formats the value using the given formatter.