Struct TryRepeatFromPersianRug 

pub struct TryRepeatFromPersianRug<T> { /* private fields */ }

Available on crate feature persian-rug only.

Cycle through the existing Proxy<T> items in the context.

Each proxy will be yielded in turn, in insertion order, and then the sequence will repeat. It is safe to insert more values to yield, and they will occur in their natural position when they are reached.

If there are no available items, generate returns None.

Example:

use boulder::{GeneratorWithPersianRug, TryRepeatFromPersianRug};
use persian_rug::{contextual, persian_rug, Context, Proxy};

#[contextual(Rug)]
struct Foo {
  a: i32
}

#[persian_rug]
struct Rug(#[table] Foo);

let mut r = Rug(Default::default());

let mut g = TryRepeatFromPersianRug::<Foo>::new();

let (f0, _) = g.generate(&mut r);
assert!(f0.is_none());

r.add(Foo { a: 0 });
r.add(Foo { a: 1 });

let (f1, _) = g.generate(&mut r);
assert_eq!(r.get(&f1.unwrap()).a, 0);
let (f2, _) = g.generate(&mut r);
assert_eq!(r.get(&f2.unwrap()).a, 1);
let (f3, _) = g.generate(&mut r);
assert_eq!(f1, f3);

r.add(Foo { a: 2} );
let (f4, _) = g.generate(&mut r);
assert_eq!(f2, f4);
let (f5, _) = g.generate(&mut r);
assert_eq!(r.get(&f5.unwrap()).a, 2);

Implementations

impl<T> TryRepeatFromPersianRug<T>

pub fn new() -> Self

Trait Implementations

impl<T> Default for TryRepeatFromPersianRug<T>

fn default() -> Self

Returns the “default value” for a type.

impl<C, T> GeneratorWithPersianRug<C> for TryRepeatFromPersianRug<T>

where C: Context + Owner<T>, T: Contextual<Context = C>,

type Output = Option<Proxy<T>>

Available on crate feature persian-rug only.

The output type.

fn generate<'b, B>(&mut self, context: B) -> (Self::Output, B)

where B: 'b + Mutator<Context = C>,

Available on crate feature persian-rug only.

Make a new object.