TRANSFORM.md

Deterministic Transforms in Typeengine

Deterministic transforms ensure document changes are predictable, testable, and auditable. All transform operations are pure functions: same input yields same output, with no side effects or hidden state.

API

• applyTransform(doc, transform) — Applies a single transform operation to a document node.
• replayTransforms(initial, transforms) — Replays a sequence of transforms to reconstruct document history.
• auditLog(transforms) — Produces a complete, verifiable log of all transforms.

Guarantees

• All transforms are deterministic and pure
• Replay reconstructs document history accurately
• Audit logs are complete and verifiable
• Handles malformed/malicious input safely
• O(n) performance in document size/history

Usage Example

  import { applyTransform, replayTransforms, auditLog } from 'typeengine/core/transform';

  const doc = { type: 'root', children: [] };
  const transforms = [
    { op: 'insert', payload: { id: 'a', type: 'paragraph' } },
    { op: 'update', payload: { id: 'a', type: 'heading' } },
    { op: 'remove', payload: { id: 'a' } },
  ];

  const replayed = replayTransforms(doc, transforms);
  console.log(replayed);
  console.log(auditLog(transforms));