add delta.partition and bump version

README.md

@@ -453,6 +453,39 @@ var text = delta.map(function(op) {
 
 ---
 
+### partition()
+
+Create an array op two arrays, the first with operations that pass the given function, the other that failed.
+
+#### Methods
+
+- `partition(predicate)`
+
+#### Parameters
+
+- `predicate` - Function to call, passing in the current operation, returning whether that operation passed
+
+#### Returns
+
+- `Array` - A new array of two Arrays, the first with passed operations, the other with failed operations
+
+#### Example
+
+```js
+var delta = new Delta().insert('Hello', { bold: true })
+                       .insert({ image: 'https://octodex.github.com/images/labtocat.png' })
+                       .insert('World!');
+
+var results = delta.partition(function(op) {
+  return typeof op.insert === 'string';
+});
+var passed = results[0];  // [{ insert: 'Hello', attributes: { bold: true }},
+                              { insert: 'World'}]
+var failed = results[1];  // [{ insert: { image: 'https://octodex.github.com/images/labtocat.png' }}]
+```
+
+---
+
 ### reduce()
 
 Applies given function against an accumulator and each operation to reduce to a single value.

lib/delta.js

@@ -90,6 +90,15 @@ Delta.prototype.map = function (predicate) {
   return this.ops.map(predicate);
 };
 
+Delta.prototype.partition = function (predicate) {
+  var passed = [], failed = [];
+  this.forEach(function(op) {
+    var target = predicate(op) ? passed : failed;
+    target.push(op);
+  });
+  return [passed, failed];
+};
+
 Delta.prototype.reduce = function (predicate, initial) {
   return this.ops.reduce(predicate, initial);
 };

package.json

@@ -1,6 +1,6 @@
 {
   "name": "quill-delta",
-  "version": "3.2.0",
+  "version": "3.3.0",
   "description": "Format for representing rich text documents and changes.",
   "author": "Jason Chen <[email protected]>",
   "homepage": "https://github.com/quilljs/delta",

test/delta/helpers.js

@@ -113,6 +113,15 @@ describe('helpers', function () {
       });
       expect(arr).toEqual(['Hello', '', 'World!']);
     });
+
+    it('partition()', function () {
+      var arr = this.delta.partition(function (op) {
+        return typeof op.insert === 'string';
+      });
+      var passed = arr[0], failed = arr[1];
+      expect(passed).toEqual([this.delta.ops[0], this.delta.ops[2]]);
+      expect(failed).toEqual([this.delta.ops[1]]);
+    });
   });
 
   describe('length()', function () {