Tree

evco::gp::tree

Trait Tree 

Source 
pub trait Tree
where
    Self: Sized + Debug + Clone,
{
    type Environment;
    type Action;

    // Required methods
    fn branch<R: Rng>(
        tg: &mut TreeGen<'_, R>,
        current_depth: usize,
    ) -> BoxTree<Self>;
    fn leaf<R: Rng>(
        tg: &mut TreeGen<'_, R>,
        current_depth: usize,
    ) -> BoxTree<Self>;
    fn count_children(&mut self) -> usize;
    fn children(&self) -> Vec<&BoxTree<Self>>;
    fn children_mut(&mut self) -> Vec<&mut BoxTree<Self>>;
    fn evaluate(&self, env: &Self::Environment) -> Self::Action;

    // Provided methods
    fn tree<R: Rng>(tg: &mut TreeGen<'_, R>) -> BoxTree<Self> { ... }
    fn child<R: Rng>(
        tg: &mut TreeGen<'_, R>,
        current_depth: usize,
    ) -> BoxTree<Self> { ... }
}
Expand description

Trait to be implemented by Genetic Programs trees.

Required Associated Types§

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type Environment

Type of input when evaluating the tree.

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type Action

The type the tree will evaluate to.

Required Methods§

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fn branch<R: Rng>( tg: &mut TreeGen<'_, R>, current_depth: usize, ) -> BoxTree<Self>

Generate a branch node (a node with at least one Tree child).

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fn leaf<R: Rng>(tg: &mut TreeGen<'_, R>, current_depth: usize) -> BoxTree<Self>

Generate a leaf node (a node without any Tree children).

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fn count_children(&mut self) -> usize

Count Self children of this node.

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fn children(&self) -> Vec<&BoxTree<Self>>

Get children of this node.

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fn children_mut(&mut self) -> Vec<&mut BoxTree<Self>>

Get mutable children of this node.

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fn evaluate(&self, env: &Self::Environment) -> Self::Action

Get indexed child of this node. Number children from 0; suggested to go left-to-right. Used to evaluate the root node of a tree.

Provided Methods§

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fn tree<R: Rng>(tg: &mut TreeGen<'_, R>) -> BoxTree<Self>

Generate a new tree within the bounds specified by TreeGen.

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fn child<R: Rng>(tg: &mut TreeGen<'_, R>, current_depth: usize) -> BoxTree<Self>

Generate a random new node to go into a tree.

Examples found in repository?
examples/snake.rs (line 165)
163    fn branch<R: Rng>(tg: &mut TreeGen<R>, current_depth: usize) -> BoxTree<Self> {
164        let direction = TurnDirection::rand(tg);
165        let true_ = Self::child(tg, current_depth + 1);
166        let false_ = Self::child(tg, current_depth + 1);
167        if tg.gen() {
168            IfDanger(direction, true_, false_).into()
169        } else {
170            IfFood(direction, true_, false_).into()
171        }
172    }
More examples
Hide additional examples
examples/symbolic_regression.rs (line 32)
31    fn branch<R: Rng>(tg: &mut TreeGen<R>, current_depth: usize) -> BoxTree<Self> {
32        let left = Self::child(tg, current_depth + 1);
33        let right = Self::child(tg, current_depth + 1);
34        match tg.gen_range(0, 7) {
35                0 => Add(left, right),
36                1 => Sub(left, right),
37                2 => Mul(left, right),
38                3 => Div(left, right),
39                4 => Neg(left),
40                5 => Sin(left),
41                6 => Cos(left),
42                _ => unreachable!(),
43            }
44            .into()
45    }

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors§