Struct proptest::sample::Selector[][src]

pub struct Selector { /* fields omitted */ }

A value for picking random values out of iterators.

This is, in a sense, a more flexible variant of Index in that it can operate on arbitrary IntoIterator values.

Initially, the selection is roughly uniform, with a very slight bias towards items earlier in the iterator.

Shrinking causes the selection to move toward items earlier in the iterator, ultimately settling on the very first, but this currently happens in a very haphazard way that may fail to find the earliest failing input.

Example

Generate a non-indexable collection and a value to pick out of it.

use proptest::prelude::*;

proptest! {
    #[test]
    fn my_test(
        names in prop::collection::hash_set("[a-z]+", 10..20),
        selector in any::<prop::sample::Selector>()
    ) {
        println!("Selected name: {}", selector.select(&names));
        // Test stuff...
    }
}

Implementations

impl Selector[src]

pub fn select<T: IntoIterator>(&self, it: T) -> T::Item[src]

Pick a random element from iterable it.

The selection is unaffected by the elements themselves, and is dependent only on the actual length of it.

it is always iterated completely.

Panics

Panics if it has no elements.

pub fn try_select<T: IntoIterator>(&self, it: T) -> Option<T::Item>[src]

Pick a random element from iterable it.

Returns None if it is empty.

The selection is unaffected by the elements themselves, and is dependent only on the actual length of it.

it is always iterated completely.

Trait Implementations

impl Arbitrary for Selector[src]

type Parameters = ()

The type of parameters that arbitrary_with accepts for configuration of the generated Strategy. Parameters must implement Default. Read more

type Strategy = SelectorStrategy

The type of Strategy used to generate values of type Self. Read more

impl Clone for Selector[src]

impl Debug for Selector[src]

Auto Trait Implementations

impl Send for Selector[src]

impl Sync for Selector[src]

impl Unpin for Selector[src]

Blanket Implementations

impl<T> Any for T where
    T: 'static + ?Sized
[src]

impl<T> Borrow<T> for T where
    T: ?Sized
[src]

impl<T> BorrowMut<T> for T where
    T: ?Sized
[src]

impl<T> From<T> for T[src]

impl<T, U> Into<U> for T where
    U: From<T>, 
[src]

impl<T> ToOwned for T where
    T: Clone
[src]

type Owned = T

The resulting type after obtaining ownership.

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 
[src]

type Error = Infallible

The type returned in the event of a conversion error.

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 
[src]

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

impl<V, T> VZip<V> for T where
    V: MultiLane<T>,