docs/SESSION_HANDOFF.md

nFlow Session 8 — Custom Node Creator (Final)

See krystv/nflow/docs/SESSION_HANDOFF.md for full details.

Compile Fixes Applied

Session 8 included a static analysis pass (no sandbox available) that identified and fixed:

1. user_nodes.rs — removed unused imports at module level (Dim/Disclosure/DType)
2. user_nodes.rs — _registry parameter renamed to suppress unused-variable warning
3. user_nodes.rs — test make_passthrough_uc mut removed
4. nfl.rs — removed unused UserCompositeStore import
5. view.rs — removed invalid pub use ExecCoverageView as ExecCoverageViewAlias (compile error)
6. view.rs — removed duplicate RunResultView2

Key Architecture

┌─────────────────────────────────────────────────────────────┐
│  UserComposite (IR)                                         │
│  uid: "user.mamba_ssm"  colour: "#a855f7"                  │
│  ports_in/out, attrs, inner_graph: Graph                    │
│  paper_url: "https://arxiv.org/abs/2312.00752"              │
└──────────────────────┬──────────────────────────────────────┘
                       │ infer_user_composite()
    ┌──────────────────▼───────────────────┐
    │  Session.run_inference               │
    │  op.starts_with("user.") →           │
    │  clone inner_graph + seed inputs +   │
    │  run inference + read output types   │
    └──────────────────────────────────────┘
                       │
    ┌──────────────────▼───────────────────┐
    │  redb (embedded database)            │
    │  global_nodes | recent_files |       │
    │  app_settings                        │
    └──────────────────────────────────────┘

Expected Test Count After Sandbox

~187 total = 174 (before) + 5 (UserComposite IR) + 3 (redb) + 5 (user_nodes inference)

Next Priorities

1. Sandbox compile verification
2. Codegen lowering for user composites
3. Double-click → editor tab in Editor canvas
4. CompositePropertiesPanel (port/attr schema editor)
5. redb path using app_data_dir()
6. npm build verification