experimental "rotate (list)" primitive relabelling option for "all but first"

HISTORY.md

@@ -7,6 +7,7 @@
     * when constructing a costume from a pixel list handle single values as greyscale
     * experimental "column _ of _" reporter relabelling option for "item _ of _"
     * experimental "width of _" reporter relabelling option for "length of _"
+    * experimental "rotate (list)" primitive relabelling option for "all but first"
     * renamed "Obsolete!" blocks to "Undefined!"
 * **Notable Fixes:**
     * fixed a glitch in the animation library's "sine in-out" easing function 
@@ -17,6 +18,9 @@
     * German
     * Turkish
 
+### 2021-01-29
+* threads, objects: new experimental "rotate (list)" primitive relabelling option for "all but first"
+
 ### 2021-01-27
 * threads: hyperized new experimental "column" primitive
 

snap.html

@@ -9,8 +9,8 @@
         <script src="src/symbols.js?version=2020-10-07"></script>
         <script src="src/widgets.js?version=2021-01-05"></script>
         <script src="src/blocks.js?version=2020-12-22"></script>
-        <script src="src/threads.js?version=2021-01-27"></script>
-        <script src="src/objects.js?version=2021-01-26"></script>
+        <script src="src/threads.js?version=2021-01-29"></script>
+        <script src="src/objects.js?version=2021-01-29"></script>
         <script src="src/gui.js?version=2021-01-21"></script>
         <script src="src/paint.js?version=2020-05-17"></script>
         <script src="src/lists.js?version=2020-12-01"></script>

src/objects.js

@@ -84,7 +84,7 @@ BlockEditorMorph, BlockDialogMorph, PrototypeHatBlockMorph,  BooleanSlotMorph,
 localize, TableMorph, TableFrameMorph, normalizeCanvas, VectorPaintEditorMorph,
 AlignmentMorph, Process, WorldMap, copyCanvas, useBlurredShadows*/
 
-modules.objects = '2021-January-26';
+modules.objects = '2021-January-29';
 
 var SpriteMorph;
 var StageMorph;
@@ -1329,6 +1329,11 @@ SpriteMorph.prototype.initBlocks = function () {
             category: 'lists',
             spec: 'all but first of %l'
         },
+        reportTableRotated: {
+            type: 'reporter',
+            category: 'lists',
+            spec: 'rotate %l'
+        },
         reportListLength: {
             type: 'reporter',
             category: 'lists',
@@ -1722,6 +1727,8 @@ SpriteMorph.prototype.blockAlternatives = {
     doHideVar: ['doShowVar'],
 
     // lists
+    reportCDR: ['reportTableRotated'],
+    reportTableRotated: ['reportCDR'],
     reportListItem: ['reportTableColumn'],
     reportTableColumn: ['reportListItem'],
     reportListLength: ['reportTableWidth'],

src/threads.js

@@ -61,7 +61,7 @@ StageMorph, SpriteMorph, StagePrompterMorph, Note, modules, isString, copy, Map,
 isNil, WatcherMorph, List, ListWatcherMorph, alert, console, TableMorph, BLACK,
 TableFrameMorph, ColorSlotMorph, isSnapObject, newCanvas, Symbol, SVG_Costume*/
 
-modules.threads = '2021-January-27';
+modules.threads = '2021-January-29';
 
 var ThreadManager;
 var Process;
@@ -2048,6 +2048,23 @@ Process.prototype.reportTableColumn = function (index, list) {
     return list.map(row => row.at(index));
 };
 
+Process.prototype.reportTableRotated = function (list) {
+    // experimental and probably controversial as a primitive,
+    // because it's so nice and easy to write in Snap!
+    this.assertType(list, 'list');
+    var width = Math.max(this.reportTableWidth(list), 1),
+        col = (tab, c) => tab.map(row => row.at(c)),
+        table = [],
+        src, i;
+    src = list.map(row =>
+        row instanceof List ? row : new List(new Array(width).fill(row))
+    );
+    for (i = 1; i <= width; i += 1) {
+        table.push(col(src, i));
+    }
+    return new List(table);
+};
+
 // Process - other basic list accessors
 
 Process.prototype.reportListLength = function (list) {