Module validate 

AST validation per ADR-008 §Validation Rules.

validate normalises an AST in place and rejects queries that violate the closed taxonomies or attempt to subvert namespace scoping:

1. Edge relations must parse to one of the 13 canonical EdgeRelation variants (ADR-002). Aliases and case differences are normalised to the canonical snake_case form stored in the database. Applies to edge patterns and WHERE e.relation = '…' constraints.
2. Node kinds must parse to one of the 6 EntityKind variants (ADR-001). Common aliases (paper → document, benchmark → dataset) are normalised. Applies to node labels and WHERE a.kind = '…' constraints.
3. Namespace scoping is a trusted parameter only. Queries must not name namespace in node property maps or WHERE conditions — the only valid source of namespace filtering is CompileOptions::scopes. This matches ADR-008 §Validation: “never trust query strings to set namespaces.”
4. Traversal depth is capped at MAX_DEPTH (10 hops). Requests above the cap are clamped, not rejected — this matches the cap the compiler applies when generating recursive CTEs.

Constants

MAX_DEPTH

Maximum traversal depth allowed by the query layer (ADR-008 §Validation).

Functions

validate

Validate and normalise an AST in place.