Struct SubgraphMerge 

pub struct SubgraphMerge<K>
where
    K: Key,
{ /* private fields */ }

Datastructure for merging subgraphs while maintaining topological sort order.

Maintains a global topo-sorted Vec of all operators. Each subgraph (merged group) occupies a contiguous range in this Vec. Merging two groups combines their ranges and re-sorts the affected window so groups remain contiguous and correctly ordered.

Implementations

impl<K> SubgraphMerge<K>

where K: Key,

pub fn new<PredsIter>( keys: impl IntoIterator<Item = K>, preds_fn: impl FnMut(K) -> PredsIter, enemies_iter: impl IntoIterator<Item = (K, K)>, ) -> Result<Self, Vec<K>>

where PredsIter: IntoIterator<Item = K>,

Creates a new SubgraphMerge from nodes and their predecessor edges.

enemies specifies pairs of nodes that must never be placed in the same subgraph. These are checked in O(1) during Self::try_merge and maintained as representatives change.

Returns Err with a cycle if the input graph is not a DAG.

pub fn find(&mut self, k: K) -> K

Find the representative of the subgraph containing k.

pub fn same_set(&mut self, u: K, v: K) -> bool

Returns true if u and v are in the same subgraph.

pub fn subgraphs(&self) -> impl Iterator<Item = &[K]>

Iterates all subgraph representatives with their topo-sorted operator slices, in topological order (by position in toposort_node).

pub fn try_merge(&mut self, u: K, v: K) -> bool

Attempts to merge the subgraphs containing u and v. Returns false if merging would create a cycle in the subgraph DAG, or if the merge is forbidden by a no-merge constraint.