@yorm/core

The deterministic object→rows projection engine of YORM. Pure functions and types — zero runtime dependencies (no Hono, Drizzle, or Yjs imports).

What lives here:

• mapping/ — the mapping DSL: defineMapping, one(...), many(...), versioned and frozen mapping contracts.
• planner/ — planProjection(mapping, input): turns a materialized object into a deterministic ProjectionPlan of upserts and scoped reconciliation deletes, plus a checkpoint.
• provenance/ — the Origin tag (yjs, sql, replay, …) carried by every plan and update.
• stores/ — the DocumentStore, ProjectionStore, and Runtime contracts that adapters implement.

Usage

import { defineMapping, many, one, planProjection } from "@yorm/core";

const patientMapping = defineMapping<{ id: string; active?: boolean }>({
  name: "fhir.Patient",
  version: 1,
  documentType: "Patient",
  projections: [
    one("patient", {
      key: ({ object }) => ({ id: object.id }),
      values: ({ object }) => ({ active: object.active ?? null }),
    }),
  ],
});

const plan = planProjection(patientMapping, {
  object: { id: "p1", active: true },
  documentId: "p1",
  documentVersion: 1,
  origin: "yjs",
});
// → { operations: [{ kind: "upsert", table: "patient", ... }], checkpoint: { ... } }

Adapters apply plans transactionally; core never performs I/O. See the root README for the full design (stable identity, column ownership, reconciliation semantics).