Struct proptest::strategy::Map

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#[must_use = "strategies do nothing unless used"]pub struct Map<S, F> { /* fields omitted */ }

[−] Expand description

Strategy and ValueTree map adaptor.

See Strategy::prop_map().

Trait Implementations

impl<S: Clone, F> Clone for Map<S, F>[+]

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fn clone(&self) -> Self[−]

Returns a copy of the value.

pub fn clone_from(&mut self, source: &Self)[−]

Performs copy-assignment from source.

impl<S: Debug, F> Debug for Map<S, F>[+]

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

Formats the value using the given formatter.

impl<S: Strategy, O: Debug, F: Fn(S::Value) -> O> Strategy for Map<S, F>[+]

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type Tree = Map<S::Tree, F>

The value tree generated by this Strategy.

type Value = O

The type of value used by functions under test generated by this Strategy.

fn new_tree(&self, runner: &mut TestRunner) -> NewTree<Self>[−]

Generate a new value tree from the given runner.

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.

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>.

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.

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.

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.

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.

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.

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.

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

Returns a strategy which picks uniformly from self and other.

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.

fn prop_shuffle(self) -> Shuffle<Self> where
    Self: Sized,
    Self::Value: Shuffleable, [−]

Shuffle the contents of the values produced by this strategy.

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.

fn sboxed(self) -> SBoxedStrategy<Self::Value> where
    Self: Sized + Send + Sync + 'static, [−]

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

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

Wraps this strategy to prevent values from being subject to shrinking.

impl<S: ValueTree, O: Debug, F: Fn(S::Value) -> O> ValueTree for Map<S, F>[+]

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type Value = O

The type of the value produced by this ValueTree.

fn current(&self) -> O[−]

Returns the current value.

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.

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.