The {N$$sep$$} brace prefix now also accepts a count range ({N-M$$}) and a
~ independent flag ({N~$$} / {N-M~$$}, repeats allowed; absent = unique).
Both tokenizers (Python engine + TS richTokenize) parse it identically
into dp-multi meta {min, max, independent}; legacy `count` is kept (== max)
so existing readers + the resolver behave unchanged for a fixed {N$$}.
Shared syntax-corpus.json locks Py≡TS parity (existing multi_pick entries
gain the new keys; new range/lone-ref cases added).
Resolution of the range/independent semantics lands next (engine resolver);
this commit is tokenizer + parity only — a fixed {N$$} is byte-for-byte
unchanged.
Option sub_category -> sub_categories[] (default []). Both pool filters (instance category_filter, nested @{} ref) become boolean expressions (and/or/not/parens; comma=or) matched against an option's tag set via the shared engine/syntax/subcat_filter matcher, applied BEFORE constraints. Exclude-null is a separate flag: instance exclude_null + the trailing !null ref marker, replacing the old 'null' keyword.
4-segment ref grammar @{uuid#name:expr!null} single-sourced across tokenize.py/scan.py/pipeline.py/_constraints.py (! excluded from name/expr captures); tokenizer REF meta now carries filter_expr + exclude_null instead of a comma-split list. scan.py findall unpack sites updated for the 4th group.
validate_payload: per-option sub_categories[] must be in the registry; optional tag_groups (UI-only axes, members in-registry, <=1 group); registry names validated via subcat_filter.validate_subcat_name (rejects whitespace, boolean/ref chars, reserved words incl. null). wp_api/_validators delegates to the same function.
Constraints stay alive via a primary-tag stopgap: _apply_constraint_to_options + _record_pick use sub_categories[0] as the matrix key; true multi-tag matrix matching is SP3. Cascade fix_subcat_delete/rename + orchestrator scrub the per-option list; instance_schemas category_filter -> string. Existing engine tests migrated to the v2 shape; added tests for the ref regex, payload validation, and multi-tag pool filtering.
Accumulated branch work that was uncommitted alongside the pair-badge feature in the prior commit. Captured as a single sweep commit so the branch can merge cleanly; future work should commit per-feature to avoid this.
Three improvements aimed at making constraints actually useful in
composed pipelines, with the conflict scanner keeping up.
## Phase A — nested constraints (engine)
Pre-2026-05 constraints only fired when the target wildcard ran as a
top-level chain module. Wildcards reached through `@{uuid}` refs from
inside another wildcard's option value silently bypassed every rule.
Composition (outfit-set wildcards, palette reuse) was a constraint
blind spot.
- New `engine/modules/_constraints.py` holds the shared application
logic (loop constraints by target uuid, look up source pick, apply
matrix/exception cells, emit unknown_constraint_source +
constraint_excludes_all_options warnings)
- `wildcard_handler.resolve` now delegates to the helper instead of
inlining the loop
- `engine/syntax/resolve._resolve_ref` calls the same helper after
fetching the catalog wildcard but before rolling — nested target
wildcards now get constrained identically to chain-level ones
- `ResolveContext` exposes `get_constraints()` + `get_picks()` so the
resolver has the back-channel it needs without depending on the
full pipeline ctx dict
## Phase B — `@{uuid:subcat[,subcat]}` filter
New optional ref syntax. `@{color:warm}` resolves the catalog wildcard
`color` but restricts its option pool to entries whose `sub_category`
is in the filter list. Same semantics as chain-level
`instance.category_filter`, but scoped per call site so one library
wildcard stays reusable.
- Python tokenizer regex extended to capture optional `:subcat,subcat`
group; `_resolve_ref` filters options pre-pick + pre-constraint
- TS `richTokenize.ts` mirrors the grammar so previews + RichTextInput
recognise the new form
- `extension/graph.ts:WC_REF_RE` + `preview-tokens.ts:REF_RE` updated
to skip the filter when extracting uuids (uuid is still group 1)
- Empty pool after filter → empty string output + new
`ref_subcategory_empty_pool` warning so the user sees an
unsatisfiable filter instead of falling back silently
## Phase C — scanner reach-set + classification refinement
Constraint scanner pre-fix:
- flagged `constraint_target_in_upstream` whenever target had ANY
upstream instance, even if a downstream / local-after / nested-after
instance was also present
- flagged `constraint_target_missing` for targets reachable only
through nested `@{}` refs
Both false-positives. Post-fix scanner computes
`localNestedReachAfter[i]` — transitive `@{}` walk through the local
catalog starting from modules at positions ≥ i — and uses it to:
- skip `target_in_upstream` when a bindable instance exists elsewhere
(downstream, local-after-self, nested-after)
- skip `target_missing` when target is reachable via nested ref from
any later chain wildcard
- still flag both when no bindable instance exists (sole-upstream,
truly-missing both remain caught)
## Tests
- 8 new Python tests under `TestNestedConstraints` +
`TestNestedSubcategoryFilter` (constraint applies through nested,
excludes-all warning, source-not-yet-picked warning, subcat narrows,
multi-subcat union, empty pool warning, empty filter no-op,
subcat+constraint composition)
- 7 new TS tests under `scanConflicts — constraint nested-reach
classification` (nested reachable doesn't flag missing, transitive
deep reach, upstream+downstream silent, upstream+local-after silent,
sole-upstream still flags, nested-from-before-constraint still
flags, nested with subcat filter still reaches)
## Numbers
- 696 pytest pass (+8)
- 1672 vitest pass (+7)
- ruff clean
- bundle 306899/307200 (301 bytes headroom)