with-macro 0.1.1

Syntactic sugar for calling methods

The with macro

Build Status crates.io Documentation

This is a macro that takes an object and lets you call methods on that object without naming it. The first argument is an expression that will be assigned to a variable in let binding. To make that binding mutable, prepend mut to the expression. Calling a function that starts with a . will be converted into a method call using this variable.

The supported forms are:

  • .method(args..)
  • let pat = .method(args..);
  • var = .method(args..);

Anything else will be evaluated unmodified as an expression.


use with_macro::with;

let vec = with! {
    mut Vec::new() =>
        let l = .len();
        assert_eq!(l, 3);

assert_eq!(vec, [1, 42, -13]);