/**
 * An append-only builder for a {@link ControlFlowGraph}, used while folding the AST.
 * @module
 */
import type { NodeId } from '../r-bridge/lang-4.x/ast/model/processing/node-id';
import type { CfgEdge } from './control-flow-graph';
import { CfgVertex, ControlFlowGraph } from './control-flow-graph';
/**
 * Records the vertices and edges of a control flow graph instead of building it, as the bottom-up fold would
 * copy an eager graph once per nesting level. {@link CfgBuilder#mergeWith|mergeWith()} only references the other
 * builder, {@link CfgBuilder#materialize|materialize()} replays everything once in recording order — the
 * order an eager merge produced, which the vertex order of a function definition's children relies on.
 */
export declare class CfgBuilder {
    private readonly operations;
    addVertex(vertex: CfgVertex, rootVertex?: boolean): this;
    addEdge(from: NodeId, to: NodeId, edge: CfgEdge): this;
    /**
     * Record that the other builder is part of this one, it must not be modified afterwards.
     * @param other       - the builder to include
     * @param forceNested - should its vertices count as nested (e.g., within a function definition)
     */
    mergeWith(other: CfgBuilder, forceNested?: boolean): this;
    /** The last vertex recorded for the given id, searching the merged builders only if we hold none. */
    getVertex(id: NodeId): CfgVertex | undefined;
    /** The ids of all vertices that are not nested, in insertion order. */
    rootIds(collected?: Set<NodeId>): ReadonlySet<NodeId>;
    /** Replays all recorded operations into a {@link ControlFlowGraph}. */
    materialize(graph?: ControlFlowGraph, nested?: boolean): ControlFlowGraph;
}