(core) Suggest correct table when converting to RefList

Summary: RecordSets now have new encoding and rendering analogous to Records: `['r', 'Table', [1, 2, 3]]` and `Table[[1, 2, 3]]`.

Test Plan: Added to nbrowser/TypeChange.ts.

Reviewers: dsagal

Reviewed By: dsagal

Differential Revision: https://phab.getgrist.com/D2987

app/client/components/TypeConversion.ts

@@ -43,7 +43,7 @@ export function addColTypeSuffix(type: string, column: ColumnRec, docModel: DocM
 
 /**
  * Looks through the data of the given column to find the first value of the form
- * [R, <tableId>, <rowId>] (a Reference value returned from a formula), and returns the tableId
+ * [R|r, <tableId>, <rowId>] (a Reference(List) value returned from a formula), and returns the tableId
  * from that.
  */
 function getRefTableIdFromData(docModel: DocModel, column: ColumnRec): string|null {
@@ -51,12 +51,21 @@ function getRefTableIdFromData(docModel: DocModel, column: ColumnRec): string|nu
   const columnData = tableData && tableData.getColValues(column.colId());
   if (columnData) {
     for (const value of columnData) {
-      if (gristTypes.isObject(value) && value[0] === 'R') {
+      if (gristTypes.isReferencing(value)) {
         return value[1];
+      } else if (gristTypes.isList(value)) {
+        const item = value[1];
+        if (gristTypes.isReference(item)) {
+          return item[1];
+        }
       } else if (typeof value === 'string') {
-        // If it looks like a formatted Ref value (e.g. "Table1[123]"), and the tableId is valid,
+        // If it looks like a formatted Ref(List) value, e.g:
+        //   - Table1[123]
+        //   - [Table1[1], Table1[2], Table1[3]]
+        //   - Table1[[1, 2, 3]]
+        // and the tableId is valid,
         // use it. (This helps if a Ref-returning formula column got converted to Text first.)
-        const match = value.match(/^(\w+)\[\d+\]/);
+        const match = value.match(/^\[?(\w+)\[/);
         if (match && docModel.docData.getTable(match[1])) {
           return match[1];
         }

app/common/gristTypes.ts

@@ -24,6 +24,7 @@ export const enum GristObjCode {
   Skip            = 'S',
   Censored        = 'C',
   Reference       = 'R',
+  ReferenceList   = 'r',
   Exception       = 'E',
   Pending         = 'P',
   Unmarshallable  = 'U',
@@ -142,10 +143,34 @@ export function isCensored(value: CellValue): value is [GristObjCode.Censored] {
 /**
  * Returns whether a value (as received in a DocAction) represents a list.
  */
- export function isList(value: CellValue): value is [GristObjCode.List, ...unknown[]] {
+export function isList(value: CellValue): value is [GristObjCode.List, ...CellValue[]] {
   return Array.isArray(value) && value[0] === GristObjCode.List;
 }
 
+/**
+ * Returns whether a value (as received in a DocAction) represents a reference to a record.
+ */
+export function isReference(value: CellValue): value is [GristObjCode.Reference, string, number] {
+  return Array.isArray(value) && value[0] === GristObjCode.Reference;
+}
+
+/**
+ * Returns whether a value (as received in a DocAction) represents a reference list (RecordSet).
+ */
+export function isReferenceList(value: CellValue): value is [GristObjCode.ReferenceList, string, number[]] {
+  return Array.isArray(value) && value[0] === GristObjCode.ReferenceList;
+}
+
+/**
+ * Returns whether a value (as received in a DocAction) represents a reference or reference list.
+ */
+export function isReferencing(value: CellValue):
+  value is [GristObjCode.ReferenceList|GristObjCode.Reference, string, number[]|number]
+{
+  return Array.isArray(value) &&
+    (value[0] === GristObjCode.ReferenceList || value[0] === GristObjCode.Reference);
+}
+
 /**
  * Returns whether a value (as received in a DocAction) represents a list or is null,
  * which is a valid value for list types in grist.

app/plugin/objtypes.ts

@@ -50,6 +50,18 @@ export class Reference {
   }
 }
 
+/**
+ * A ReferenceList represents a reference to a number of rows in a table. It is simply a pair of a string tableId
+ * and a numeric array rowIds.
+ */
+export class ReferenceList {
+  constructor(public tableId: string, public rowIds: number[]) {}
+
+  public toString(): string {
+    return `${this.tableId}[[${this.rowIds}]]`;
+  }
+}
+
 /**
  * A RaisedException represents a formula error. It includes the exception name, message, and
  * optional details.
@@ -140,6 +152,8 @@ export function encodeObject(value: unknown): CellValue {
       return null;
     } else if (value instanceof Reference) {
       return ['R', value.tableId, value.rowId];
+    } else if (value instanceof ReferenceList) {
+      return ['r', value.tableId, value.rowIds];
     } else if (value instanceof Date) {
       const timestamp = value.valueOf() / 1000;
       if ('timezone' in value) {
@@ -185,6 +199,7 @@ export function decodeObject(value: CellValue): unknown {
       case 'L': return (args as CellValue[]).map(decodeObject);
       case 'O': return mapValues(args[0] as {[key: string]: CellValue}, decodeObject, {sort: true});
       case 'P': return new PendingValue();
+      case 'r': return new ReferenceList(String(args[0]), args[1]);
       case 'R': return new Reference(String(args[0]), args[1]);
       case 'S': return new SkipValue();
       case 'C': return new CensoredValue();