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impl Iterator for Generator<Input=()>.

This commit is contained in:
whitequark 2016-08-13 00:07:08 +00:00 committed by edef
parent 145c18125a
commit d4b7c427c9
2 changed files with 41 additions and 0 deletions

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@ -42,6 +42,8 @@ pub enum State {
/// the state is `State::Runnable` after creation and suspension, and `State::Unavailable`
/// once the generator function returns or panics.
///
/// When the input type is `()`, a generator implements the Iterator trait.
///
/// # Example
///
/// ```
@ -58,6 +60,20 @@ pub enum State {
/// println!("{:?}", add_one.resume(3)); // prints Some(4)
/// println!("{:?}", add_one.resume(0)); // prints None
/// ```
///
/// # Iterator example
///
/// ```
/// use fringe::{OsStack, Generator};
///
/// let stack = OsStack::new(0).unwrap();
/// let mut nat = Generator::new(stack, move |yielder, ()| {
/// for i in 1.. { yielder.generate(i) }
/// });
/// println!("{:?}", nat.next()); // prints Some(0)
/// println!("{:?}", nat.next()); // prints Some(1)
/// println!("{:?}", nat.next()); // prints Some(2)
/// ```
#[derive(Debug)]
pub struct Generator<Input: Send, Output: Send, Stack: stack::Stack> {
state: State,
@ -199,3 +215,10 @@ impl<Input, Output, Stack> Yielder<Input, Output, Stack>
self.generate_bare(Some(item))
}
}
impl<Output, Stack> Iterator for Generator<(), Output, Stack>
where Output: Send, Stack: stack::Stack {
type Item = Output;
fn next(&mut self) -> Option<Self::Item> { self.resume(()) }
}

18
tests/iterator.rs Normal file
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@ -0,0 +1,18 @@
// This file is part of libfringe, a low-level green threading library.
// Copyright (c) whitequark <whitequark@whitequark.org>
// See the LICENSE file included in this distribution.
extern crate fringe;
use fringe::OsStack;
use fringe::generator::Generator;
#[test]
fn producer() {
let stack = OsStack::new(0).unwrap();
let mut gen = Generator::new(stack, move |yielder, ()| {
for i in 0.. { yielder.generate(i) }
});
assert_eq!(gen.next(), Some(0));
assert_eq!(gen.next(), Some(1));
assert_eq!(gen.next(), Some(2));
}