Module graph 

Core DAG (Directed Acyclic Graph) data structure.

This module provides the fundamental graph structure with nodes and edges.

Performance Characteristics

• Node/Edge Insertion: O(1) amortized with HashMap and cached adjacency lists
• Child/Parent Lookups: O(1) via cached adjacency lists (not O(E) iteration)
• ID→Index Mapping: O(1) via HashMap (not O(N) scan)
• Node Width: O(1) via pre-computed cache

Memory Overhead

Per node:

• ~100 bytes (node data, caches, adjacency list headers)

Per edge:

• ~16 bytes (adjacency list entries, both directions)

Security

• No unsafe code
• For untrusted input, consider limiting maximum nodes/edges to prevent resource exhaustion
• Maximum node ID: usize::MAX (up to 20 decimal digits)

Structs

DAG

A Directed Acyclic Graph (DAG) with ASCII rendering capabilities.

Enums

RenderMode

Rendering mode for the DAG visualization.