Struct NodePool

pub struct NodePool<'a> {
    pub inner_vec: Vec<Node<'a>>,
    pub counter: u32,
}

Arena-based container storing Nodes

A NodePool is essentially just a Vec<Node> that is indexed by NodeIDs. Each parsing construct stores NodeIDs which refer to indices within the NodePool. It acts like a flattened version of the AST where each node can be easily iterated over and tracked.

NodePool::iter and NodePool::iter_mut can be used for iterating over the contents of the pool.

Safety

Removing or inserting an element at a position other than the end might invalidate every other NodeID and therefore the AST. Removing and de-allocating an individual Node is not possible due to this effect. However, the result can be feigned in the tree by “deleting” the node from its parent. See NodePool::delete_node.

Fields

inner_vec: Vec<Node<'a>>

counter: u32

Implementations

impl<'a> NodePool<'a>

pub fn get(&self, id: NodeID) -> Option<&'a Node<'_>>

pub fn get_mut(&mut self, id: NodeID) -> Option<&'a mut Node<'_>>

pub fn iter( &self, ) -> impl Iterator<Item = &Node<'a>> + DoubleEndedIterator<Item = &Node<'a>>

pub fn iter_mut( &mut self, ) -> impl Iterator<Item = &mut Node<'a>> + DoubleEndedIterator<Item = &mut Node<'a>>

pub fn print_tree(&self)

Outputs a (somewhat) legible representation of the tree to stdout.

pub fn root_id(&self) -> NodeID

Returns the NodeID of the first element in the pool.

pub fn delete_node(&mut self, index_id: NodeID)

Removes a Node from its parents’ “children”.

This action mimicks the effect of a deletion, but does not actually deallocate or remove the node from the pool.

Trait Implementations

impl<'a> Debug for NodePool<'a>

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

Formats the value using the given formatter.

impl<'a> Index<NodeID> for NodePool<'a>

type Output = Node<'a>

The returned type after indexing.

fn index(&self, index: NodeID) -> &Self::Output

Performs the indexing (container[index]) operation.

impl<'a> IndexMut<NodeID> for NodePool<'a>

fn index_mut(&mut self, index: NodeID) -> &mut Self::Output

Performs the mutable indexing (container[index]) operation.