JSON: New list reporters (VM) (#60)

* add getListArrayContents

* add kind for data_listarraycontents

* add sequence for list.arraycontents

* Update jsexecute.js

* fixes

src/blocks/scratch3_data.js

@@ -21,6 +21,7 @@ class Scratch3DataBlocks {
             data_hidevariable: this.hideVariable,
             data_showvariable: this.showVariable,
             data_listcontents: this.getListContents,
+            data_listarraycontents: this.getListArrayContents,
             data_addtolist: this.addToList,
             data_deleteoflist: this.deleteOfList,
             data_deletealloflist: this.deleteAllOfList,
@@ -90,6 +91,23 @@ class Scratch3DataBlocks {
         this.changeMonitorVisibility(args.LIST.id, false);
     }
 
+    getListArrayContents (args, util) {
+        const list = util.target.lookupOrCreateList(
+            args.LIST.id, args.LIST.name);
+
+        // If block is running for monitors, return copy of list as an array if changed.
+        if (util.thread.updateMonitor) {
+            // Return original list value if up-to-date, which doesn't trigger monitor update.
+            if (list._monitorUpToDate) return list.value;
+            // If value changed, reset the flag and return a copy to trigger monitor update.
+            // Because monitors use Immutable data structures, only new objects trigger updates.
+            list._monitorUpToDate = true;
+            return list.value.slice();
+        }
+
+        return list.value;
+    }
+
     getListContents (args, util) {
         const list = util.target.lookupOrCreateList(
             args.LIST.id, args.LIST.name);

src/compiler/irgen.js

@@ -274,6 +274,11 @@ class ScriptTreeGenerator {
                 kind: 'list.contents',
                 list: this.descendVariable(block, 'LIST', LIST_TYPE)
             };
+        case 'data_listarraycontents':
+            return {
+                kind: 'list.arraycontents',
+                list: this.descendVariable(block, 'LIST', LIST_TYPE)
+            };
 
         case 'event_broadcast_menu': {
             const broadcastOption = block.fields.BROADCAST_OPTION;

src/compiler/jsexecute.js

@@ -553,6 +553,15 @@ runtimeFunctions.listContents = `const listContents = list => {
     return list.value.join('');
 }`;
 
+/**
+ * Get the raw array form of a list.
+ * @param {import('../engine/variable')} list The list.
+ * @returns {string} Stringified form of the list.
+ */
+runtimeFunctions.listArrayContents = `const listArrayContents = list => {
+    return list.value;
+}`;
+
 /**
  * Convert a color to an RGB list
  * @param {*} color The color value to convert

src/compiler/jsgen.js

@@ -505,6 +505,8 @@ class JSGenerator {
             return new TypedInput(`listContains(${this.referenceVariable(node.list)}, ${this.descendInput(node.item).asUnknown()})`, TYPE_BOOLEAN);
         case 'list.contents':
             return new TypedInput(`listContents(${this.referenceVariable(node.list)})`, TYPE_STRING);
+        case 'list.arraycontents':
+            return new TypedInput(`listArrayContents(${this.referenceVariable(node.list)})`, TYPE_STRING);
         case 'list.get': {
             const index = this.descendInput(node.index);
             if (environment.supportsNullishCoalescing) {

src/engine/blocks.js

@@ -751,7 +751,8 @@ class Blocks {
             // block but in the case of monitored reporters that have arguments,
             // map the old id to a new id, creating a new monitor block if necessary
             if (block.fields && Object.keys(block.fields).length > 0 &&
-                block.opcode !== 'data_variable' && block.opcode !== 'data_listcontents') {
+                block.opcode !== 'data_variable' && block.opcode !== 'data_listcontents' &&
+                block.opcode !== 'data_listarraycontents') {
 
                 // This block has an argument which needs to get separated out into
                 // multiple monitor blocks with ids based on the selected argument
@@ -779,6 +780,8 @@ class Blocks {
                 isSpriteLocalVariable = !(this.runtime.getTargetForStage().variables[block.fields.VARIABLE.id]);
             } else if (block.opcode === 'data_listcontents') {
                 isSpriteLocalVariable = !(this.runtime.getTargetForStage().variables[block.fields.LIST.id]);
+            } else if (block.opcode === 'data_listarraycontents') {
+                isSpriteLocalVariable = !(this.runtime.getTargetForStage().variables[block.fields.LIST.id]);
             }
 
             const isSpriteSpecific = isSpriteLocalVariable ||
@@ -806,7 +809,8 @@ class Blocks {
                         params: this._getBlockParams(block),
                         // @todo(vm#565) for numerical values with decimals, some countries use comma
                         value: '',
-                        mode: block.opcode === 'data_listcontents' ? 'list' : 'default'
+                        // @todo let extensions use list monitors!
+                        mode: (block.opcode === 'data_listcontents' || block.opcode === 'data_listarraycontents') ? 'list' : 'default'
                     }));
                 }
             }
@@ -971,7 +975,7 @@ class Blocks {
             truncatedOpcode = 'variable';
         } else if (variable.type === Variable.LIST_TYPE) {
             fieldName = 'LIST';
-            truncatedOpcode = 'listcontents';
+            truncatedOpcode = 'listarraycontents';
         } else {
             // TODO handle broadcast messages later
             return [];