Period consumers — implementation and remaining scope
Status: refinement and the core Excel binding contract published in 2.8.0. RFC 0042 and RFC 0043 are implemented. Core/CLI 2.8.0 pairs with Protocol 2.11.0 and Format 2.0. The verified numeric Excel exporter is available in source 0.9.0; standalone npm publication remains demand-gated.
Implemented outcome
Formulas retain explicit year, quarter, month or date identity in refinement and in requested workbook calculations. Both use the existing five-series registry and variant selection. Neither infers a default for a missing period.
| Consumer | Implementation | Remaining scope |
|---|---|---|
| Refinement | Stated numeric period values remain fixed while ordinary scalar gaps are ranked. Structured per-output issues are visible in JSON and CLI text. | Period ranges/defaults, stochastic VOI and improved interval algorithms. |
| Excel emitter | Trusted periodBindings produce exact identity lookups with whole-series validation. Static named ranges alone still refuse. | Non-arithmetic custom expression parity and general result chaining. |
| Workbook builder | Explicit calculation IDs export result/input sheets and selected series tables, with exact variants/overrides. | Structural period-set changes inside a workbook and reverse import of additional inputs. |
| Verification | Native Excel 16.0 build 20326: 14 scenarios, 48 checks, exact supported-case parity and save/reopen. | Other spreadsheet engines and application versions. |
Workbook decisions resolved by RFC 0043
- Whole-row reordering is supported by canonical identity lookup; fixed positions never substitute for a period. Source identities form a closed snapshot.
- Missing inputs are #N/A, invalid identities/nonnumeric inputs are #VALUE!, and a true zero remains numeric. Guards validate the entire selected series.
- The caller explicitly chooses calculation IDs. Context applies to those extra calculations; existing pack sheets and their metric dictionary are unchanged.
- Excel 2016-compatible functions are used; native tests identify the actual application version tested. Formula snapshots alone are not the parity proof.
- Additional workbook edits are export-only. Import refuses them explicitly, rather than silently discarding new period or scalar input edits.
See the native verification record and the RFCs for the complete acceptance contracts. Before expanding any scope, pin input/period identity, missing-value behavior and actual recalculation checks.
Next development decisions
RFC 0044 now proposes an explicit-date projection, supported by an executable example. The adapter is not implemented; full DCF coupling still needs complete economic coverage and valuation-anchor rules. Lease-up net_cash_flow covers receipts, concessions and TI/LC, not complete property/equity cash flow. Speculative leasing still needs renewal, vacancy, market-reset and TI/LC rules. These consumers select stated data; they do not create those economic models. Relative Qn/Mn, currency conversion, bps precision and module-defined period series remain separate contracts.