GraphForeachNode

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API Reference

GraphForeachNode

Description

Iterate over each live node of given graph.

The loop variable is a GraphNode handle carrying the owning graph plus a stable node id. Marking nodes for deletion is allowed during iteration, but structural changes such as adding nodes, adding edges, clearing, or committing changes will invalidate the traversal and abort on the next iteration step.

Scratch-state operations such as GraphNodeVisit, GraphNodeUnvisit, GraphMarkNodeForDeletion, GraphUnmarkNodeForDeletion, GraphMarkEdgeForRemoval, and GraphUnmarkEdgeForRemoval are the intended mutation tools inside traversal-driven analysis or rewrite passes.

Parameters

Name	Direction	Description
`g`	in,out	Graph to iterate over.
`node`	in	Name of the `GraphNode` loop variable.

Usage example (Cross-references)

Usage examples (Cross-references)

In Graph.Foreach.c:59:

    
    static void city_reset_visits(CityGraph *graph) {
        GraphForeachNode(graph, node) {
            GraphNodeUnvisit(node);
        }

In Graph.Foreach.c:96:

    
    static bool test_graph_city_reachability(void) {
        WriteFmt("Testing GraphForeachNode and GraphNodeForeachNeighbor for reachability\n");
    
        CityGraph graph = GraphInitWithDeepCopy(StrInitCopy, StrDeinit);

In Graph.Foreach.c:119:

    
        city_reset_visits(&graph);
        GraphForeachNode(&graph, node) {
            result = result && (GraphNodeVisitCount(node) == 0);
        }

In Graph.Foreach.c:147:

        GraphAddEdge(&graph, c, d);
    
        GraphForeachNode(&graph, node) {
            (void)MapEnsurePtr(&counts, GraphNodeGetId(node), 0);
            GraphNodeForeachNeighbor(node, neighbor) {

In Graph.Foreach.c:199:

    
    static bool test_graph_node_iteration_rejects_structural_mutation_deadend(void) {
        WriteFmt("Testing GraphForeachNode rejects structural mutation (should abort)\n");
    
        typedef Graph(int) IntGraph;

In Graph.Foreach.c:207:

        GraphAddNodeR(&graph, 2);
    
        GraphForeachNode(&graph, node) {
            (void)node;
            (void)GraphAddNodeR(&graph, 3);

In Graph.Ops.c:43:

        GraphAddEdge(&graph, c, a);
    
        GraphForeachNode(&graph, node) {
            if (GraphNodeData(&graph, node) == 20) {
                GraphMarkNodeForDeletion(node);

In Graph.Ops.c:111:

        GraphAddEdge(&graph, b, c);
    
        GraphForeachNode(&graph, node) {
            if (GraphNodeGetId(node) == a) {
                GraphNodeForeachNeighbor(node, neighbor) {

Last updated on April 28, 2026

GraphEmpty GraphGetNode