Deferred

Rust包，用于帮助执行代码逻辑的延迟执行。

想法

此包可用于特定操作，在这些操作中，您需要在不确定的时间执行逻辑的不同部分，但不能使用futures或其他异步操作。

使用

在 Cargo.toml 中记录

[dependencies]
deferred = "1.1"

您的包模块

#[macro_use]
extern crate deferred;

use deferred::*;

fn foo(v: i32) -> Deferred<i32> {
    deferred!(v, [
        |c| state!(c.state() + 1),
        |c| foo2(c.state()).into(),
        |c| state!(c.state() + 2)
    ])
}

fn foo2(v: i32) -> Deferred<i32> {
    deferred!(v, [
      |c| state!(c.state() * 2),
      |c| state!(c.state() * 3)
    ])
}

{
  let d = foo(1);
  assert!(d.can_resume());
  assert_eq!(d.state(), Some(&1));

  let d = d.resume().unwrap();
  assert!(d.can_resume());
  assert_eq!(d.state(), Some(&2));

  let d = d.resume().unwrap();
  assert!(d.can_resume());
  assert_eq!(d.state(), Some(&4));

  let d = d.resume().unwrap();
  assert!(d.can_resume());
  assert_eq!(d.state(), Some(&12));

  let d = d.resume().unwrap();
  assert!(!d.can_resume());
  assert_eq!(d.state(), Some(&14));
}
// IS EQUIVALENT TO:
{
  let d = foo(1);
  assert_eq!(d.consume(), 14);
}