custom block definition api, highly experimental, very much under construction

HISTORY.md

@@ -44,6 +44,9 @@
 * **Translation Updates:**
     * German
 
+### 2022-04-27
+* threads, byob: custom block definition api, highly experimental, very much under construction
+
 ### 2022-04-26
 * gui: distinguish between embedded blocks code and raw data in PNGs
 * morphic: fixed bulk-drop of images

snap.html

@@ -17,13 +17,13 @@
         <script src="src/symbols.js?version=2021-03-03"></script>
         <script src="src/widgets.js?version=2021-17-09"></script>
         <script src="src/blocks.js?version=2022-04-22"></script>
-        <script src="src/threads.js?version=2022-04-20"></script>
+        <script src="src/threads.js?version=2022-04-27"></script>
         <script src="src/objects.js?version=2022-04-25"></script>
         <script src="src/scenes.js?version=2022-03-03"></script>
         <script src="src/gui.js?version=2022-04-26"></script>
         <script src="src/paint.js?version=2021-07-05"></script>
         <script src="src/lists.js?version=2022-02-07"></script>
-        <script src="src/byob.js?version=2022-04-20"></script>
+        <script src="src/byob.js?version=2022-04-27"></script>
         <script src="src/tables.js?version=2022-01-28"></script>
         <script src="src/sketch.js?version=2021-11-03"></script>
         <script src="src/video.js?version=2019-06-27"></script>

src/byob.js

@@ -111,7 +111,7 @@ ArgLabelMorph*/
 
 // Global stuff ////////////////////////////////////////////////////////
 
-modules.byob = '2022-April-20';
+modules.byob = '2022-April-27';
 
 // Declarations
 
@@ -530,6 +530,37 @@ CustomBlockDefinition.prototype.updateTranslations = function (text) {
     });
 };
 
+// CustomBlockDefinition API, highly experimental & under construction
+
+CustomBlockDefinition.prototype.setBlockLabel = function (abstractSpec) {
+    // private - only to be called from a Process that also does housekeeping
+    // abstract block specs replace the inputs with underscores,
+    // e.g. "move _ steps", "say _", "_ + _"
+    var count = abstractSpec.split(' ').filter(word => word === '_').length,
+        inputNames = this.inputNames(),
+        parts = [],
+        spec = abstractSpec;
+
+    if (count !== inputNames.length) { // not yet sure about this... (jens)
+        throw new Error('expecting the number of inputs to match');
+    }
+    if (spec.startsWith('_ ')) {
+        parts.push('');
+        spec = spec.slice(2);
+    }
+    if (spec.endsWith(' _')) {
+        spec = spec.slice(0, -2);
+    }
+    parts = parts.concat(spec.split(' _ '));
+    spec = '';
+    parts.forEach((part, i) =>
+        spec += (part + (
+            inputNames[i] ? ' %\'' + inputNames[i] + '\' ' : '')
+        )
+    );
+    this.spec = spec.trim();
+};
+
 // CustomBlockDefinition picturing
 
 CustomBlockDefinition.prototype.scriptsPicture = function () {

src/threads.js

@@ -65,7 +65,7 @@ StagePickerMorph*/
 
 /*jshint esversion: 11, bitwise: false, evil: true*/
 
-modules.threads = '2022-April-20';
+modules.threads = '2022-April-27';
 
 var ThreadManager;
 var Process;
@@ -5624,6 +5624,62 @@ Process.prototype.reportBasicBlockAttribute = function (attribute, block) {
     return '';
 };
 
+Process.prototype.doSetBlockAttribute = function (attribute, block, val) {
+    // highly experimental & under construction
+    var choice = this.inputOption(attribute),
+        rcvr = this.blockReceiver(),
+        ide = rcvr.parentThatIsA(IDE_Morph),
+        oldSpec,
+        count = 1,
+        expr,
+        def,
+        template;
+
+    this.assertType(block, ['command', 'reporter', 'predicate']);
+    expr = block.expression;
+    def = expr.isGlobal ? expr.definition : rcvr.getMethod(expr.semanticSpec);
+    oldSpec = def.blockSpec();
+
+    switch (choice) {
+    case 'label':
+        def.setBlockLabel(val);
+        break;
+    case 'definition':
+        return;
+    case 'category':
+        return;
+    case 'global?':
+        return;
+    }
+
+    // make sure the spec is unique
+    while (rcvr.doubleDefinitionsFor(def).length > 0) {
+        count += 1;
+        def.spec += (' (' + count + ')');
+    }
+    
+    // update all block instances:
+    // refer to "updateDefinition()" of BlockEditorMorph:
+    template = rcvr.paletteBlockInstance(def);
+
+    if (def.isGlobal) {
+        rcvr.allBlockInstances(def).reverse().forEach(
+            block => block.refresh()
+        );
+    } else {
+        rcvr.allDependentInvocationsOf(oldSpec).reverse().forEach(
+            block => block.refresh(def)
+        );
+    }
+    if (template) {
+        template.refreshDefaults();
+    }
+    ide.flushPaletteCache();
+    ide.categories.refreshEmpty();
+    ide.refreshPalette();
+    ide.recordUnsavedChanges();
+};
+
 Process.prototype.reportAttributeOf = function (attribute, name) {
     // hyper-dyadic
     // note: specifying strings in the left input only accesses