optimized internal matrix ops by speeding up shape & rank determinati…

…on assuming well-formed tables

HISTORY.md

@@ -17,6 +17,9 @@
     * fixed speech balloons inside ASK menus
     * added safeguard against accidentally querying too many list dimensions (forgetting to transpose a convolution)
 
+2024-01-10
+* lists, threads, objects: optimized internal matrix ops by speeding up shape & rank determination assuming well-formed tables
+
 2024-01-09
 * pixels library: added Sobel edge-detection variants for left/right/top/bottom
 * threads: use the microphone's sample rate for playing back lists of samples once it has been used, otherwise 44.1 kHz

snap.html

@@ -17,12 +17,12 @@
         <script src="src/symbols.js?version=2023-07-13"></script>
         <script src="src/widgets.js?version=2023-05-24"></script>
         <script src="src/blocks.js?version=2023-11-24"></script>
-        <script src="src/threads.js?version=2024-01-09"></script>
-        <script src="src/objects.js?version=2024-01-08"></script>
+        <script src="src/threads.js?version=2024-01-10"></script>
+        <script src="src/objects.js?version=2024-01-10"></script>
         <script src="src/scenes.js?version=2022-10-29"></script>
         <script src="src/gui.js?version=2024-01-24"></script>
         <script src="src/paint.js?version=2023-05-24"></script>
-        <script src="src/lists.js?version=2024-01-08"></script>
+        <script src="src/lists.js?version=2024-01-10"></script>
         <script src="src/byob.js?version=2023-07-14"></script>
         <script src="src/tables.js?version=2023-07-05"></script>
         <script src="src/sketch.js?version=2023-05-24"></script>

src/lists.js

@@ -65,7 +65,7 @@ Context, ZERO, WHITE*/
 
 // Global settings /////////////////////////////////////////////////////
 
-modules.lists = '2024-January-08';
+modules.lists = '2024-January-10';
 
 var List;
 var ListWatcherMorph;
@@ -660,6 +660,14 @@ List.prototype.rank = function () {
     return rank;
 };
 
+List.prototype.quickRank = function () {
+    // answer the number of my dimensions
+    // only look at the first item of each dimension,
+    // assuming regularly shaped nested lists
+    var item = this.at(1);
+    return item instanceof List ? item.quickRank() + 1 : 1;
+};
+
 List.prototype.shape = function () {
     // answer a list of the maximum size for each dimension
     var dim,
@@ -678,6 +686,19 @@ List.prototype.shape = function () {
     return shp;
 };
 
+List.prototype.quickShape = function () {
+    // answer a list of each dimension's size
+    // only look at the first item of each dimension,
+    // assuming regularly shaped nested lists
+    var shp = [],
+        item = this;
+    while (item instanceof List) {
+        shp.push(item.length());
+        item = item.at(1);
+    }
+    return new List(shp);
+};
+
 List.prototype.getDimension = function (rank = 0) {
     // private - answer a list of all elements of the specified rank
     if (rank < 1) {return new List(); }

src/objects.js

@@ -95,7 +95,7 @@ embedMetadataPNG, SnapExtensions, SnapSerializer, snapEquals*/
 
 /*jshint esversion: 11*/
 
-modules.objects = '2024-January-08';
+modules.objects = '2024-January-10';
 
 var SpriteMorph;
 var StageMorph;
@@ -4340,7 +4340,7 @@ SpriteMorph.prototype.doSwitchToCostume = function (id, noShadow) {
         h = 0,
         stage;
     if (id instanceof List) { // try to turn a list of pixels into a costume
-        if (id.shape().at(2) <= 4) {
+        if (id.quickShape().at(2) <= 4) {
             if (this.costume) {
                 // recycle dimensions of current costume
                 w = this.costume.width();

src/threads.js

@@ -65,7 +65,7 @@ StagePickerMorph, CustomBlockDefinition, CommentMorph*/
 
 /*jshint esversion: 11, bitwise: false, evil: true*/
 
-modules.threads = '2024-January-09';
+modules.threads = '2024-January-10';
 
 var ThreadManager;
 var Process;
@@ -2378,6 +2378,11 @@ Process.prototype.reportRank = function (data) {
     return data instanceof List ? data.rank() : 0;
 };
 
+Process.prototype.reportQuickRank = function (data) {
+    // private - assume a regularly shaped nested list
+    return data instanceof List ? data.quickRank() : 0;
+};
+
 Process.prototype.reportDimensions = function (data) {
     return data instanceof List ? data.shape() : new List();
 };
@@ -4518,7 +4523,7 @@ Process.prototype.hyperMonadic = function (baseOp, arg) {
 };
 
 Process.prototype.hyperDyadic = function (baseOp, a, b) {
-    var match = Math.min(this.reportRank(a), this.reportRank(b));
+    var match = Math.min(this.reportQuickRank(a), this.reportQuickRank(b));
     return this.hyperZip(baseOp, a, b, match, match);
 };
 
@@ -4528,8 +4533,8 @@ Process.prototype.hyperZip = function (baseOp, a, b, zipa, zipb) {
     // this allows to write 2d matrix convolutions for 3+d inputs with
     // 2d kernels e.g. for image processing without having to first
     // reshape the kernel matrix to match the broadcast shape.
-    var arank = this.reportRank(a),
-        brank = this.reportRank(b),
+    var arank = this.reportQuickRank(a),
+        brank = this.reportQuickRank(b),
         len, i, result;
     if (arank === brank || (arank <= zipa && brank <= zipb)) {
         if (arank + brank === 0) {
@@ -7204,7 +7209,7 @@ Process.prototype.reportNewCostume = function (pixels, width, height, name) {
     }
     if (width <= 0 || height <= 0) {
         // try to interpret the pixels as matrix
-        shp = this.reportDimensions(pixels);
+        shp = pixels.quickShape();
         if (shp.at(2) > 4) {
             height = shp.at(1);
             width = shp.at(2);