Struct evalexpr::Function

pub struct Function { /* private fields */ }

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(|argument| {
    Ok(argument.clone())
})).unwrap(); // Do proper error handling here
assert_eq!(eval_with_context("id(4)", &context), Ok(Value::from(4)));

Implementations

impl Function

pub fn new<F>(function: F) -> Self where
    F: Fn(&Value) -> EvalexprResult<Value>,
    F: Send + Sync + 'static,
    F: Clone, 

Creates a user-defined function.

The function is boxed for storage.

Trait Implementations

impl Clone for Function

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Function

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

Formats the value using the given formatter.