[CLONE-NOISE-CONSTANT-TABLE] Per-language const tables in lang/*.rs are reported as the repo's worst duplication

[MelbourneDeveloper]

Defect

Deslop reports its own crates/deslop-core/src/lang/ modules as a top-worst-band duplication family. These are false positives: the clusters are per-language constant tables, and there is nothing to extract.

cluster id	rank	kind	occurrences
0aa0d20956d67315	4	nearly_identical	lang/csharp.rs, lang/dart.rs, lang/rust_lang.rs
b64bef9fb9aff7c9	7	loosely_similar	lang/csharp.rs +4
257cc1642e1b6335	8	loosely_similar	lang/csharp.rs +3

Why it is a false positive

0aa0d20956d67315 covers const BINDING_KINDS: &[BindingKind] plus const REFERENCE_TABLE: ReferenceTable in three language modules. The values are entirely disjoint — each names its own grammar's node kinds — and the arities differ (5 / 4 / 6 binding kinds; 6 / 3 / 5 skip_parent_kinds). The shared abstraction (BindingKind, ReferenceTable) is already extracted; what remains is per-language data that cannot be shared.

This is precisely the rationale [CLONE-NOISE-CONSTANT-TABLE] states:

A table of distinct named constants is data: there is no shared control flow and no abstraction to hoist, so there is nothing a reader could extract.

Why the filter misses it

cluster_filters/constant_table.rs requires every member's right-hand side to be a plain literal:

Any right-hand side that is not a plain literal — a call, a name, an attribute, an interpolated string — takes the member out of the shape and keeps the cluster visible.

Here the right-hand sides are const-constructor calls (BindingKind::new(...)) and a struct literal (ReferenceTable { ... }), so covers_only_constants returns false and the cluster survives. The narrowness is deliberate and documented, so this is a coverage gap rather than defective code — but the result is a false positive in the worst band, and it inflates duplicated_loc.

Suggested direction

Extend the constant-table shape to admit right-hand sides that are themselves const-evaluable data — const-fn constructor calls and struct/array literals over literals — while still requiring members to differ in raw bytes so a verbatim-copied table stays visible.