reconcile/docs/advanced-ts.md

Advanced usage (TypeScript)

Edit provenance

Track which changes came from where using reconcileWithHistory:

const result = reconcileWithHistory(
  'Hello world',
  'Hello beautiful world',
  'Hi world'
);

console.log(result.text);    // "Hi beautiful world"
console.log(result.history); /*
[
  {
    "text": "Hello",
    "history": "RemovedFromRight"
  },
  {
    "text": "Hi",
    "history": "AddedFromRight"
  },
  {
    "text": " beautiful",
    "history": "AddedFromLeft"
  },
  {
    "text": " ",
    "history": "Unchanged"
  },
  {
    "text": "world",
    "history": "Unchanged"
  }
]
*/

Tokenisation strategies

Reconcile offers different ways to split text for merging:

• Word tokeniser ("Word") — Splits on word boundaries (recommended for prose)
• Character tokeniser ("Character") — Individual characters (fine-grained control)
• Line tokeniser ("Line") — Line-by-line (similar to git merge or more precisely git merge-file)

Cursor tracking

Reconcile automatically tracks cursor positions through merges which is handy in a collaborative editor.

const result = reconcile(
  'Hello world',
  {
    text: 'Hello beautiful world',
    cursors: [{ id: 1, position: 6 }], // After "Hello "
  },
  {
    text: 'Hi world',
    cursors: [{ id: 2, position: 0 }], // At the beginning
  }
);

// Result: "Hi beautiful world" with repositioned cursors
console.log(result.text);    // "Hi beautiful world"
console.log(result.cursors); // [{ id: 2, position: 0 }, { id: 1, position: 3 }]

The cursors list is sorted by the character position (not id-s).