feat(json-crdt-extensions): 🎸 improve OverlayPoint ref operations

src/json-crdt-extensions/peritext/overlay/OverlayPoint.ts

@@ -2,6 +2,7 @@ import {Point} from '../rga/Point';
 import {compare} from '../../../json-crdt-patch/clock';
 import {OverlayRef, OverlayRefSliceEnd, OverlayRefSliceStart} from './refs';
 import {printTree} from 'sonic-forest/lib/print/printTree';
+import type {SplitSlice} from '../slice/SplitSlice';
 import type {HeadlessNode} from 'sonic-forest/lib/types';
 import type {Printable} from '../../../util/print/types';
 import type {Slice} from '../slice/types';
@@ -13,9 +14,12 @@ import type {Slice} from '../slice/types';
  */
 export class OverlayPoint extends Point implements Printable, HeadlessNode {
   /**
-   * Sorted list of all references to rich-text constructs.
+   * Hash of text contents until the next {@link OverlayPoint}. This field is
+   * modified by the {@link Overlay} tree.
    */
-  public readonly refs: OverlayRef[] = [];
+  public hash: number = 0;
+
+  // ------------------------------------------------------------------- layers
 
   /**
    * Sorted list of layers, contains the interval from this point to the next
@@ -24,38 +28,6 @@ export class OverlayPoint extends Point implements Printable, HeadlessNode {
    */
   public readonly layers: Slice[] = [];
 
-  /**
-   * Collapsed slices - markers (block splits), which represent a single point
-   * in the text, even if the start and end of the slice are different.
-   */
-  public readonly markers: Slice[] = [];
-
-  /**
-   * Hash of text contents until the next {@link OverlayPoint}. This field is
-   * modified by the {@link Overlay} tree.
-   */
-  public hash: number = 0;
-
-  public removeSlice(slice: Slice): void {
-    const refs = this.refs;
-    const length = refs.length;
-    for (let i = 0; i < length; i++) {
-      const ref = refs[i];
-      if (
-        ref === slice ||
-        (ref instanceof OverlayRefSliceStart && ref.slice === slice) ||
-        (ref instanceof OverlayRefSliceEnd && ref.slice === slice)
-      ) {
-        refs.splice(i, 1);
-        break;
-      }
-    }
-    this.removeLayer(slice);
-    this.removeMarker(slice);
-  }
-
-  // ------------------------------------------------------------------- layers
-
   /**
    * Inserts a slice to the list of layers which contains the area from this
    * point until the next one. The operation is idempotent, so inserting the
@@ -110,58 +82,108 @@ export class OverlayPoint extends Point implements Printable, HeadlessNode {
 
   // ------------------------------------------------------------------ markers
 
+  /**
+   * Collapsed slices - markers (block splits), which represent a single point
+   * in the text, even if the start and end of the slice are different.
+   * @deprecated This field might happen to be not necessary.
+   */
+  public readonly markers: Slice[] = [];
+
   /**
    * Inserts a slice to the list of markers which represent a single point in
    * the text, even if the start and end of the slice are different. The
    * operation is idempotent, so inserting the same slice twice will not change
    * the state of the point. The markers are sorted by the slice ID.
    *
    * @param slice Slice to add to the marker list.
+   * @deprecated This method might happen to be not necessary.
    */
   public addMarker(slice: Slice): void {
-    const points = this.markers;
-    const length = points.length;
+    /** @deprecated */
+    const markers = this.markers;
+    const length = markers.length;
     if (!length) {
-      points.push(slice);
+      markers.push(slice);
       return;
     }
     // We attempt to insert from the end of the list, as it is the most likely
     // scenario. And `.push()` is more efficient than `.unshift()`.
-    const lastSlice = points[length - 1];
+    const lastSlice = markers[length - 1];
     const sliceId = slice.id;
     const cmp = compare(lastSlice.id, sliceId);
     if (cmp < 0) {
-      points.push(slice);
+      markers.push(slice);
       return;
     } else if (!cmp) return;
     for (let i = length - 2; i >= 0; i--) {
-      const currSlice = points[i];
+      const currSlice = markers[i];
       const cmp = compare(currSlice.id, sliceId);
       if (cmp < 0) {
-        points.splice(i + 1, 0, slice);
+        markers.splice(i + 1, 0, slice);
         return;
       } else if (!cmp) return;
     }
-    points.unshift(slice);
+    markers.unshift(slice);
   }
 
   /**
    * Removes a slice from the list of markers, which represent a single point in
    * the text, even if the start and end of the slice are different.
    *
    * @param slice Slice to remove from the marker list.
+   * @deprecated This method might happen to be not necessary.
    */
   public removeMarker(slice: Slice): void {
-    const points = this.markers;
-    const length = points.length;
+    /** @deprecated */
+    const markers = this.markers;
+    const length = markers.length;
     for (let i = 0; i < length; i++) {
-      if (points[i] === slice) {
-        points.splice(i, 1);
+      if (markers[i] === slice) {
+        markers.splice(i, 1);
         return;
       }
     }
   }
 
+  // --------------------------------------------------------------------- refs
+
+  /**
+   * Sorted list of all references to rich-text constructs.
+   */
+  public readonly refs: OverlayRef[] = [];
+
+  public addMarkerRef(slice: SplitSlice): void {
+    this.refs.push(slice);
+    this.addMarker(slice);
+  }
+
+  public addLayerStartRef(slice: Slice): void {
+    this.refs.push(new OverlayRefSliceStart(slice));
+    this.addLayer(slice);
+  }
+
+  public addLayerEndRef(slice: Slice): void {
+    this.refs.push(new OverlayRefSliceEnd(slice));
+  }
+
+  public removeRef(slice: Slice): void {
+    const refs = this.refs;
+    const length = refs.length;
+    for (let i = 0; i < length; i++) {
+      const ref = refs[i];
+      if (
+        ref === slice ||
+        (ref instanceof OverlayRefSliceStart && ref.slice === slice) ||
+        (ref instanceof OverlayRefSliceEnd && ref.slice === slice)
+      ) {
+        refs.splice(i, 1);
+        break;
+      }
+    }
+    this.removeLayer(slice);
+    this.removeMarker(slice);
+  }
+
   // ---------------------------------------------------------------- Printable
 
   public toStringName(tab: string, lite?: boolean): string {

src/json-crdt-extensions/peritext/overlay/__tests__/OverlayPoint.spec.ts

@@ -1,6 +1,7 @@
 import {Point} from '../../rga/Point';
 import {setup} from '../../slice/__tests__/setup';
 import {OverlayPoint} from '../OverlayPoint';
+import {OverlayRefSliceEnd, OverlayRefSliceStart} from '../refs';
 
 const setupOverlayPoint = () => {
   const deps = setup();
@@ -196,9 +197,9 @@ describe('markers', () => {
 
   test('can add tree markers by appending them', () => {
     const {peritext, getPoint} = setupOverlayPoint();
-    const marker1 = peritext.slices.insSplit(peritext.rangeAt(6, 0), '<p>');
-    const marker2 = peritext.slices.insSplit(peritext.rangeAt(6, 0), '<p>');
-    const marker3 = peritext.slices.insSplit(peritext.rangeAt(6, 0), '<p>');
+    const marker1 = peritext.slices.insSplit(peritext.rangeAt(6, 1), '<p>');
+    const marker2 = peritext.slices.insSplit(peritext.rangeAt(6, 2), '<p>');
+    const marker3 = peritext.slices.insSplit(peritext.rangeAt(6, 3), '<p>');
     const point = getPoint(marker2.start);
     point.addMarker(marker1);
     point.addMarker(marker2);
@@ -210,9 +211,9 @@ describe('markers', () => {
 
   test('can remove markers', () => {
     const {peritext, getPoint} = setupOverlayPoint();
-    const marker1 = peritext.slices.insSplit(peritext.rangeAt(6, 0), '<p>');
-    const marker2 = peritext.slices.insSplit(peritext.rangeAt(6, 0), '<p>');
-    const marker3 = peritext.slices.insSplit(peritext.rangeAt(6, 0), '<p>');
+    const marker1 = peritext.slices.insSplit(peritext.rangeAt(6, 1), '<p>');
+    const marker2 = peritext.slices.insSplit(peritext.rangeAt(6, 1), '<p>');
+    const marker3 = peritext.slices.insSplit(peritext.rangeAt(6, 2), '<p>');
     const point = getPoint(marker1.start);
     point.addMarker(marker2);
     point.addMarker(marker1);
@@ -232,3 +233,78 @@ describe('markers', () => {
     expect(point.markers.length).toBe(0);
   });
 });
+
+describe('refs', () => {
+  test('can add marker ref', () => {
+    const {peritext, getPoint} = setupOverlayPoint();
+    const marker = peritext.slices.insSplit(peritext.rangeAt(10, 1), '<p>');
+    const point = getPoint(marker.start);
+    expect(point.markers.length).toBe(0);
+    expect(point.refs.length).toBe(0);
+    point.addMarkerRef(marker);
+    expect(point.markers.length).toBe(1);
+    expect(point.refs.length).toBe(1);
+    expect(point.markers[0]).toBe(marker);
+    expect(point.refs[0]).toBe(marker);
+  });
+
+  test('can add layer ref (start)', () => {
+    const {peritext, getPoint} = setupOverlayPoint();
+    const slice = peritext.slices.insErase(peritext.rangeAt(0, 4), 123);
+    const point = getPoint(slice.start);
+    expect(point.layers.length).toBe(0);
+    expect(point.refs.length).toBe(0);
+    point.addLayerStartRef(slice);
+    expect(point.layers.length).toBe(1);
+    expect(point.refs.length).toBe(1);
+    expect(point.layers[0]).toBe(slice);
+    expect((point.refs[0] as OverlayRefSliceStart).slice).toBe(slice);
+  });
+
+  test('can add layer ref (end)', () => {
+    const {peritext, getPoint} = setupOverlayPoint();
+    const slice = peritext.slices.insErase(peritext.rangeAt(0, 4), 123);
+    const point = getPoint(slice.end);
+    expect(point.layers.length).toBe(0);
+    expect(point.refs.length).toBe(0);
+    point.addLayerEndRef(slice);
+    expect(point.layers.length).toBe(0);
+    expect(point.refs.length).toBe(1);
+    expect((point.refs[0] as OverlayRefSliceEnd).slice).toBe(slice);
+  });
+
+  test('can add marker and layer start', () => {
+    const {peritext, getPoint} = setupOverlayPoint();
+    const marker = peritext.slices.insSplit(peritext.rangeAt(10, 1), '<p>');
+    const slice = peritext.slices.insErase(peritext.rangeAt(10, 4), 123);
+    const point = getPoint(slice.end);
+    expect(point.layers.length).toBe(0);
+    expect(point.markers.length).toBe(0);
+    expect(point.refs.length).toBe(0);
+    point.addMarkerRef(marker);
+    point.addLayerStartRef(slice);
+    expect(point.layers.length).toBe(1);
+    expect(point.markers.length).toBe(1);
+    expect(point.refs.length).toBe(2);
+  });
+
+  test('can remove marker and layer', () => {
+    const {peritext, getPoint} = setupOverlayPoint();
+    const marker = peritext.slices.insSplit(peritext.rangeAt(10, 1), '<p>');
+    const slice = peritext.slices.insErase(peritext.rangeAt(10, 4), 123);
+    const point = getPoint(slice.end);
+    point.addMarkerRef(marker);
+    point.addLayerStartRef(slice);
+    expect(point.layers.length).toBe(1);
+    expect(point.markers.length).toBe(1);
+    expect(point.refs.length).toBe(2);
+    point.removeRef(slice);
+    expect(point.layers.length).toBe(0);
+    expect(point.markers.length).toBe(1);
+    expect(point.refs.length).toBe(1);
+    point.removeRef(marker);
+    expect(point.layers.length).toBe(0);
+    expect(point.markers.length).toBe(0);
+    expect(point.refs.length).toBe(0);
+  });
+});