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faebryk

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How Faebryk's TypeGraph works (GraphView + Zig edges), how to traverse/resolve references, and how FabLL types/traits map onto edge types. Use when working with TypeGraph traversal, edge types, or building type-aware queries.

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Faebryk Core Module

The Faebryk core here is the TypeGraph + edge types implemented in Zig and exposed to Python via faebryk.core.faebrykpy.

Source-of-truth for API + behavior:

  • src/faebryk/core/faebrykpy.py (Python-facing wrapper + type-safe EdgeTrait.traverse)
  • src/faebryk/core/zig/gen/faebryk/typegraph.pyi (public stubbed API surface)
  • src/faebryk/core/zig/src/faebryk/* (Zig implementation)

Quick Start

import faebryk.core.faebrykpy as fbrk
import faebryk.core.graph as graph

g = graph.GraphView.create()
tg = fbrk.TypeGraph.create(g=g)

Relevant Files

  • src/faebryk/core/faebrykpy.py (re-exports + EdgeTraversal + type-safe EdgeTrait.traverse)
  • src/faebryk/core/zig/gen/faebryk/typegraph.pyi (TypeGraph stub)
  • Key edge types (imported by faebrykpy.py):
    • EdgeComposition (parent/child structure)
    • EdgeTrait / Trait (trait attachment)
    • EdgePointer (references)
    • EdgeInterfaceConnection (interface connections)
    • EdgeOperand (solver operand wiring)
    • EdgeType / EdgeNext (type graph plumbing)
  • Linker:
    • Linker (used by compiler/linking stages)

Dependants (Call Sites)

  • FabLL: src/faebryk/core/node.py (binds Python classes into the TypeGraph; uses composition/trait edges)
  • Compiler: src/atopile/compiler/* (creates and links TypeGraphs)
  • Solver: src/faebryk/core/solver/* (operand edges and instance traversal)
  • Build/export pipeline: src/atopile/build_steps.py (visits type/instance edges for PCB/layout features)

How to Work With / Develop / Test

Core Concepts

  • GraphView + TypeGraph: a TypeGraph is created against a GraphView: 
    import faebryk.core.graph as graph
import faebryk.core.faebrykpy as fbrk

g = graph.GraphView.create()
tg = fbrk.TypeGraph.create(g=g)
  • Type nodes vs instance nodes:
    • TypeGraph stores type definitions (“what exists structurally on a type”)
    • GraphView also holds instances created from those types (“a concrete design graph”)
  • EdgeTraversal: TypeGraph.ensure_child_reference(..., path=[...]) uses EdgeTraversal items to walk references through the type graph.

Development Workflow

  1. Zig-side changes: edit src/faebryk/core/zig/src/faebryk/* (edges, typegraph internals).
  2. Rebuild bindings: ato dev compile (imports faebryk.core.zig).
  3. Python ergonomics: add wrappers/helpers in src/faebryk/core/faebrykpy.py (example: type-safe EdgeTrait.traverse).

Testing

  • TypeGraph-heavy tests live in compiler/runtime suites:
    • ato dev test --llm test/compiler/test_typegraph.py -q
    • ato dev test --llm test/compiler/test_runtime.py -q
  • Zig-backed traversal tests:
    • ato dev test --llm test/core/zig/test_interface_pathfinder.py -q

Best Practices

  • Import edges/TypeGraph via faebryk.core.faebrykpy (so callers get Python helpers, not just raw generated types).
  • Prefer type-safe trait traversal:
    • EdgeTrait.traverse(trait_type=SomeTrait) over stringly-typed trait_type_name=....
  • When building reference paths, be explicit about edge semantics (composition vs pointer vs trait) rather than relying on implicit string behavior.