Module level 

Level descriptors + the semantics dictionaries that let the core handle unknown kinds/keys without hardcoding their names, and let the UI render any language/metric set purely from data: edge kinds (EdgeKindSpec), node/edge attributes (AttributeSpec, grouped via AttributeGroup), node kinds (NodeKindSpec) and cycle kinds (CycleKindSpec).

The dictionaries are maps keyed by the kind/attribute/group name; the spec value holds only the remaining metadata.

Structs

AttributeGroup

A named group of attributes (UI section). Keyed by group name in Level::attribute_groups; attributes reference it via AttributeSpec::group. Metadata only — storage stays flat.

AttributeSpec

Describes one attribute key (on a node or an edge). Everything the UI needs to label, explain, format, compute and threshold the metric — so the viewer hardcodes no metric by name.

CycleKindSpec

Label + description of one cycle kind ("mutual" / "chain").

EdgeKindSpec

Semantics of one edge kind. Keyed by the edge kind in Level::edge_kinds. flow is the single source of truth for “is this information flow”: counted in coupling/cycles AND drawn when true; structural (e.g. contains) and excluded/hidden when false.

Grouping

How the viewer should cluster nodes in the diagram. Exactly one of key (group by the value of a node attribute, e.g. crate) or function (a named grouper the viewer implements, e.g. dir — derive the folder from the path). Absent → the viewer falls back to its default dir grouper.

Level

An analysis level the plugin can produce, with the semantics needed to score and draw it. The orchestrator merges in centrally-computed attribute specs and the computed ui block before writing the snapshot.

NodeKindSpec

Visual + label semantics of one node kind ("file" / "external" / …). Keyed by kind in Level::node_kinds.

Thresholds

Two-tier per-metric thresholds (at/under info is fine; above warning is likely a problem). Carried on an AttributeSpec; produced by a plugin (language-calibrated), absent when a metric has no calibration.