Struct proptest::strategy::LazyJust

source ·
pub struct LazyJust<T, F: Fn() -> T> { /* private fields */ }
Expand description

A Strategy which always produces a single value value and never simplifies. If T is Clone, you should use Just instead.

This is a generalization of Just and works by calling the provided Fn () -> T in .current() every time. This is not a very interesting strategy, but is required in cases where T is not Clone. It is also used in proptest_derive where we can’t assume that your type is Clone.

It is important that the function used be pure.

Implementations§

source§

impl<T, F: Fn() -> T> LazyJust<T, F>

source

pub fn new(function: F) -> Self

Constructs a LazyJust strategy given the function/closure that produces the value.

It is important that the function used be pure.

Trait Implementations§

source§

impl<T, F: Clone + Fn() -> T> Clone for LazyJust<T, F>

source§

fn clone(&self) -> Self

Returns a copy of the value. Read more
1.0.0 · source§

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
source§

impl<T, F: Fn() -> T> Debug for LazyJust<T, F>

source§

fn fmt(&self, fmt: &mut Formatter<'_>) -> Result

Formats the value using the given formatter. Read more
source§

impl<T: Debug, F: Clone + Fn() -> T> Strategy for LazyJust<T, F>

§

type Tree = LazyJust<T, F>

The value tree generated by this Strategy.
§

type Value = T

The type of value used by functions under test generated by this Strategy. Read more
source§

fn new_tree(&self, _: &mut TestRunner) -> NewTree<Self>

Generate a new value tree from the given runner. Read more
source§

fn prop_map<O: Debug, F: Fn(Self::Value) -> O>(self, fun: F) -> Map<Self, F>
where Self: Sized,

Returns a strategy which produces values transformed by the function fun. Read more
source§

fn prop_map_into<O: Debug>(self) -> MapInto<Self, O>
where Self: Sized, Self::Value: Into<O>,

Returns a strategy which produces values of type O by transforming Self with Into<O>. Read more
source§

fn prop_perturb<O: Debug, F: Fn(Self::Value, TestRng) -> O>( self, fun: F, ) -> Perturb<Self, F>
where Self: Sized,

Returns a strategy which produces values transformed by the function fun, which is additionally given a random number generator. Read more
source§

fn prop_flat_map<S: Strategy, F: Fn(Self::Value) -> S>( self, fun: F, ) -> Flatten<Map<Self, F>>
where Self: Sized,

Maps values produced by this strategy into new strategies and picks values from those strategies. Read more
source§

fn prop_ind_flat_map<S: Strategy, F: Fn(Self::Value) -> S>( self, fun: F, ) -> IndFlatten<Map<Self, F>>
where Self: Sized,

Maps values produced by this strategy into new strategies and picks values from those strategies while considering the new strategies to be independent. Read more
source§

fn prop_ind_flat_map2<S: Strategy, F: Fn(Self::Value) -> S>( self, fun: F, ) -> IndFlattenMap<Self, F>
where Self: Sized,

Similar to prop_ind_flat_map(), but produces 2-tuples with the input generated from self in slot 0 and the derived strategy in slot 1. Read more
source§

fn prop_filter<R: Into<Reason>, F: Fn(&Self::Value) -> bool>( self, whence: R, fun: F, ) -> Filter<Self, F>
where Self: Sized,

Returns a strategy which only produces values accepted by fun. Read more
source§

fn prop_filter_map<F: Fn(Self::Value) -> Option<O>, O: Debug>( self, whence: impl Into<Reason>, fun: F, ) -> FilterMap<Self, F>
where Self: Sized,

Returns a strategy which only produces transformed values where fun returns Some(value) and rejects those where fun returns None. Read more
source§

fn prop_union(self, other: Self) -> Union<Self>
where Self: Sized,

Returns a strategy which picks uniformly from self and other. Read more
source§

fn prop_recursive<R: Strategy<Value = Self::Value> + 'static, F: Fn(BoxedStrategy<Self::Value>) -> R>( self, depth: u32, desired_size: u32, expected_branch_size: u32, recurse: F, ) -> Recursive<Self::Value, F>
where Self: Sized + 'static,

Generate a recursive structure with self items as leaves. Read more
source§

fn boxed(self) -> BoxedStrategy<Self::Value>
where Self: Sized + 'static,

Erases the type of this Strategy so it can be passed around as a simple trait object. Read more
source§

fn no_shrink(self) -> NoShrink<Self>
where Self: Sized,

Wraps this strategy to prevent values from being subject to shrinking. Read more
source§

impl<T: Debug, F: Fn() -> T> ValueTree for LazyJust<T, F>

§

type Value = T

The type of the value produced by this ValueTree.
source§

fn simplify(&mut self) -> bool

Attempts to simplify the current value. Notionally, this sets the “high” value to the current value, and the current value to a “halfway point” between high and low, rounding towards low. Read more
source§

fn complicate(&mut self) -> bool

Attempts to partially undo the last simplification. Notionally, this sets the “low” value to one plus the current value, and the current value to a “halfway point” between high and the new low, rounding towards low. Read more
source§

fn current(&self) -> Self::Value

Returns the current value.
source§

impl<T, F: Copy + Fn() -> T> Copy for LazyJust<T, F>

Auto Trait Implementations§

§

impl<T, F> Freeze for LazyJust<T, F>
where F: Freeze,

§

impl<T, F> RefUnwindSafe for LazyJust<T, F>
where F: RefUnwindSafe,

§

impl<T, F> Send for LazyJust<T, F>
where F: Send,

§

impl<T, F> Sync for LazyJust<T, F>
where F: Sync,

§

impl<T, F> Unpin for LazyJust<T, F>
where F: Unpin,

§

impl<T, F> UnwindSafe for LazyJust<T, F>
where F: UnwindSafe,

Blanket Implementations§

source§

impl<T> Any for T
where T: 'static + ?Sized,

source§

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
source§

impl<T> Borrow<T> for T
where T: ?Sized,

source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
source§

impl<T> BorrowMut<T> for T
where T: ?Sized,

source§

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
source§

impl<T> CloneToUninit for T
where T: Clone,

source§

default unsafe fn clone_to_uninit(&self, dst: *mut T)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dst. Read more
source§

impl<T> CloneToUninit for T
where T: Copy,

source§

unsafe fn clone_to_uninit(&self, dst: *mut T)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dst. Read more
source§

impl<T> From<T> for T

source§

fn from(t: T) -> T

Returns the argument unchanged.

source§

impl<T, U> Into<U> for T
where U: From<T>,

source§

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

source§

impl<T> ToOwned for T
where T: Clone,

§

type Owned = T

The resulting type after obtaining ownership.
source§

fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
source§

fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
source§

impl<T, U> TryFrom<U> for T
where U: Into<T>,

§

type Error = Infallible

The type returned in the event of a conversion error.
source§

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
source§

impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

§

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

The type returned in the event of a conversion error.
source§

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
source§

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

source§

fn vzip(self) -> V