feat(ng-repeat): initial implementaion of ng-repeat.

- adds support for content bindings via '[]'.
- directives module

modules/directives/src/ng_repeat.js

@@ -0,0 +1,94 @@
+import {describe, xit, it, expect, beforeEach, ddescribe, iit} from 'test_lib/test_lib';
+
+import {Decorator, Component, Template} from 'core/annotations/annotations';
+import {OnChange} from 'core/compiler/interfaces';
+import {ViewPort} from 'core/compiler/viewport';
+import {View} from 'core/compiler/view';
+import {isPresent, isBlank} from 'facade/lang';
+import {ListWrapper, List} from 'facade/collection';
+
+@Template({
+  selector: '[ng-repeat]',
+  bind: {
+    'in': 'iterable[]'
+  }
+})
+export class NgRepeat extends OnChange {
+  viewPort: ViewPort;
+  iterable;
+  constructor(viewPort: ViewPort) {
+    this.viewPort = viewPort;
+  }
+  onChange(changes) {
+    var iteratorChanges = changes['iterable'];
+    if (isBlank(iteratorChanges) || isBlank(iteratorChanges.currentValue)) {
+      this.viewPort.clear();
+      return;
+    }
+
+    // TODO(rado): check if change detection can produce a change record that is
+    // easier to consume than current.
+    var recordViewTuples = [];
+    iteratorChanges.currentValue.forEachRemovedItem(
+      (removedRecord) => ListWrapper.push(recordViewTuples, new RecordViewTuple(removedRecord, null))
+    );
+
+    iteratorChanges.currentValue.forEachMovedItem(
+      (movedRecord) => ListWrapper.push(recordViewTuples, new RecordViewTuple(movedRecord, null))
+    );
+
+    var insertTuples = NgRepeat.bulkRemove(recordViewTuples, this.viewPort);
+
+    iteratorChanges.currentValue.forEachAddedItem(
+      (addedRecord) => ListWrapper.push(insertTuples, new RecordViewTuple(addedRecord, null))
+    );
+
+    NgRepeat.bulkInsert(insertTuples, this.viewPort);
+
+    for (var i = 0; i < insertTuples.length; i++) {
+      this.perViewChange(insertTuples[i].view, insertTuples[i].record);
+    }
+  }
+
+  perViewChange(view, record) {
+    view.setLocal('ng-repeat', record.item);
+    // Uncomment when binding is ready.
+    // view.setLocal('index', record.item);
+  }
+
+  static bulkRemove(tuples, viewPort) {
+    tuples.sort((a, b) => a.record.previousIndex - b.record.previousIndex);
+    var movedTuples = [];
+    for (var i = tuples.length - 1; i >= 0; i--) {
+      var tuple = tuples[i];
+      var view = viewPort.remove(tuple.record.previousIndex);
+      if (isPresent(tuple.record.currentIndex)) {
+        tuple.view = view;
+        ListWrapper.push(movedTuples, tuple);
+      }
+    }
+    return movedTuples;
+  }
+
+  static bulkInsert(tuples, viewPort) {
+    tuples.sort((a, b) => a.record.currentIndex - b.record.currentIndex);
+    for (var i = 0; i < tuples.length; i++) {
+      var tuple = tuples[i];
+      if (isPresent(tuple.view)) {
+        viewPort.insert(tuple.view, tuple.record.currentIndex);
+      } else {
+        tuple.view = viewPort.create(tuple.record.currentIndex);
+      }
+    }
+    return tuples;
+  }
+}
+
+class RecordViewTuple {
+  view: View;
+  record: any;
+  constructor(record, view) {
+    this.record = record;
+    this.view = view;
+  }
+}