Linnet

Overview

Linnet is a graph library for tensor networks, Feynman diagrams, and other workflows where the boundary of a subgraph matters. Its central representation is a half-edge graph. An ordinary internal edge is a pair of half-edges, while an external edge has one dangling half-edge. A node owns incident half-edges, and a subgraph is a selection of half-edges rather than a detached copy of the graph.

Choose a task

• To add Linnet to a Rust project and validate a graph with a boundary, follow the Rust guide and the exact HedgeGraphBuilder reference.
• To parse and inspect a DOT graph from Python, follow the source-built Python guide.
• To select an internal subgraph and compute a cycle basis, continue with the first-graph tutorial.
• To enumerate cycles, cuts, or connected regions, use the graph-algorithms guide with the HedgeGraph reference.
• To render a tree of existing DOT files and rebuild only changed figures, use the Clinnet command-line guide.
• To draw an editable graph in Typst, begin with the Typst guide, then continue to the Linnest Typst guide layout coordinates are deliberately separate from graph identity.

A working model

A Linnet workflow has four parts:

• construct a graph with HedgeGraphBuilder, or parse a DOT graph;
• retain the typed identifiers returned for half-edges, nodes, and edges;
• describe the region of interest with one of the subgraph representations;
• run traversal or mutation operations against that subgraph and the graph’s involution.

The involution is the pairing map for half-edges. A paired entry represents an internal edge; an identity entry represents a dangling edge and records its flow. Edge orientation and flow are related concepts, but they are not interchangeable. Consult the API reference for the exact variants and conversion rules in your Linnet release.

Construction and interchange

The Rust package can be added directly from crates.io:

[dependencies]
linnet = "0.17"

Programmatic construction uses HedgeGraphBuilder. DOT support provides a convenient human-readable interchange and debugging format; it can carry global, node, edge, and half-edge attributes. Treat DOT as a representation boundary, not as a substitute for the typed graph invariants. Validate or handle parser errors before running algorithms.

The drawing feature adds layout support. Layout is separate from graph identity: coordinates may change without changing the topology. Linnet itself does not provide a supported renderer; use DOT, Clinnet, or Linnest at the presentation boundary.

Related crates

The rendered guides, native Rustdoc, and generated Python API are the canonical references. Contributors can follow the stores, invariants, mutation flow, and feature boundaries in the Linnet implementation architecture.