Trait calc_graph::Calc

pub trait Calc {
    type Value;
    fn add_dep(&mut self, seen: &mut BitSet, dep: usize);
    fn eval(&mut self, dirty: &mut BitSet) -> (usize, Self::Value);
}

Calculates a node's value.

Associated Types

type Value

The type of values calculated by the node.

Required Methods

fn add_dep(&mut self, seen: &mut BitSet, dep: usize)

When this node is used as a precedent, add_dep is called by dependent nodes when they are created.

Func nodes forward calls to add_dep to their precedents. Source nodes remember their dependencies so that they can mark them dirty when the source node changes.

Arguments

• seen - A BitSet that can be used to skip a call to add_dep when this node is reachable from a dependency via multiple routes.
• dep - The usize id of the dependent node.

fn eval(&mut self, dirty: &mut BitSet) -> (usize, Self::Value)

Returns the value held within the node and the version number of the inputs used to calcuate that value. The value is recalculated if needed.

To calculate a node as a function of some precedent nodes:

1. On creation, each func node is assigned a numerical id. If this id is not contained within the dirty bitset, immediately return the cached version number and value. Otherwise, remove this id from the dirty bitset.
2. Call eval on each of the precedent nodes and remember the version number and value returned by each precedent.
3. Calculate version = max(prec1_version, prec2_version, ...). If this version is lower than or equal to the cached version number, immediately return the cached version number and value.
4. Calculate a new value for this node: value = f(prec1_value, prec2_value, ...). Update the cache with the calculated version and the new value.
5. Return (version, value.clone()).

Returns a tuple containing:

• A usize version number indicating the highest version number of this node's precedents
• A Clone of the value calculated

Arguments

• dirty - A BitSet that indicates the nodes that were marked dirty due to an update to a Node<Source>.

Implementations on Foreign Types

impl<C: Calc> Calc for Arc<Mutex<C>>

Implements Calc for SharedNode.

type Value = C::Value

fn add_dep(&mut self, seen: &mut BitSet, dep: usize)

fn eval(&mut self, dirty: &mut BitSet) -> (usize, C::Value)

impl<T> Calc for Box<Calc<Value = T> + Send>

Implements Calc for BoxedNode.

type Value = T

fn add_dep(&mut self, seen: &mut BitSet, dep: usize)

fn eval(&mut self, dirty: &mut BitSet) -> (usize, T)

Implementors

• impl<T: Clone> Calc for Source<T> type Value = T;

• impl<T: Clone> Calc for Const<T> type Value = T;

• impl<T: Clone, F: FnOnce() -> T> Calc for Lazy<T, F> type Value = T;

• impl<C1: Calc, T: Clone + PartialEq, F: FnMut(C1::Value) -> T> Calc for Func1<C1, T, F> type Value = T;

• impl<C1: Calc, C2: Calc, T: Clone + PartialEq, F: FnMut(C1::Value, C2::Value) -> T> Calc for Func2<C1, C2, T, F> type Value = T;

• impl<C1: Calc, C2: Calc, C3: Calc, T: Clone + PartialEq, F: FnMut(C1::Value, C2::Value, C3::Value) -> T> Calc for Func3<C1, C2, C3, T, F> type Value = T;

• impl<C1: Calc, C2: Calc, C3: Calc, C4: Calc, T: Clone + PartialEq, F: FnMut(C1::Value, C2::Value, C3::Value, C4::Value) -> T> Calc for Func4<C1, C2, C3, C4, T, F> type Value = T;

• impl<C1: Calc, C2: Calc, C3: Calc, C4: Calc, C5: Calc, T: Clone + PartialEq, F: FnMut(C1::Value, C2::Value, C3::Value, C4::Value, C5::Value) -> T> Calc for Func5<C1, C2, C3, C4, C5, T, F> type Value = T;

• impl<C1: Calc, C2: Calc, C3: Calc, C4: Calc, C5: Calc, C6: Calc, T: Clone + PartialEq, F: FnMut(C1::Value, C2::Value, C3::Value, C4::Value, C5::Value, C6::Value) -> T> Calc for Func6<C1, C2, C3, C4, C5, C6, T, F> type Value = T;

• impl<C1: Calc, C2: Calc, C3: Calc, C4: Calc, C5: Calc, C6: Calc, C7: Calc, T: Clone + PartialEq, F: FnMut(C1::Value, C2::Value, C3::Value, C4::Value, C5::Value, C6::Value, C7::Value) -> T> Calc for Func7<C1, C2, C3, C4, C5, C6, C7, T, F> type Value = T;

• impl<C1: Calc, C2: Calc, C3: Calc, C4: Calc, C5: Calc, C6: Calc, C7: Calc, C8: Calc, T: Clone + PartialEq, F: FnMut(C1::Value, C2::Value, C3::Value, C4::Value, C5::Value, C6::Value, C7::Value, C8::Value) -> T> Calc for Func8<C1, C2, C3, C4, C5, C6, C7, C8, T, F> type Value = T;