Function filterMapNodes

packages/effect/src/Graph.ts:2027–2052

(
  mutable: MutableGraph<N, E, T>,
  f: (data: N) => Option.Option<N>
)

 * @since 3.18.0
 */
export const filterMapNodes = <N, E, T extends Kind = "directed">(
  mutable: MutableGraph<N, E, T>,
  f: (data: N) => Option.Option<N>
): void => {
  assertMutable(mutable)
  const impl = graphImpl(mutable)

  const nodesToRemove: Array<NodeIndex> = []

  // First pass: identify nodes to remove and transform data for nodes to keep
  for (const [index, data] of impl.nodes) {
    const result = f(data)
    if (Option.isSome(result)) {
      // Transform node data
      impl.nodes.set(index, result.value)
    } else {
      // Mark for removal
      nodesToRemove.push(index)
    }
  }

  // Second pass: remove filtered out nodes and their edges
  for (const nodeIndex of nodesToRemove) {
    removeNode(mutable, nodeIndex)
  }
}

/**
 * Filters and optionally transforms edges in a mutable graph using a predicate function.