new "numbers" constructor primitive in List category

HISTORY.md

@@ -25,7 +25,7 @@
     * new "get graphic effect" reporter
     * new "get pen attribute" reporter
     * new "write" command in pen category (used to be "label" in tools)
-    * new "is empty", "map","keep", "combine" and "for each" primitives in list category
+    * new "numbers", "is empty", "map","keep", "combine" and "for each" primitives in list category
     * new "for" loop and "if then else" reporter primitives in the Control category
     * added "neg", "lg" (log2) and "2^" selectors to monadic function reporter in Operators
     * added "^" reporter (power of) in the Operators category
@@ -73,6 +73,7 @@
 
 ### 2019-04-26
 * Lists, Threads, Objects: new "is empty" predicate primitive in List category
+* Threads, Objects: new "numbers" constructor primitive in List category
 
 ### 2019-04-26
 * updated Catalan translation (for new HOF prims)

src/objects.js

@@ -1280,6 +1280,14 @@ SpriteMorph.prototype.initBlocks = function () {
             defaults: [1, null, localize('thing')]
         },
 
+        // numbers - linked
+        reportNumbers: {
+            type: 'reporter',
+            category: 'lists',
+            spec: 'numbers from %n to %n',
+            defaults: [1, 10]
+        },
+
         // HOFs
         reportMap: {
             type: 'reporter',
@@ -2429,6 +2437,7 @@ SpriteMorph.prototype.blockTemplates = function (category) {
         blocks.push('=');
 
         blocks.push(block('reportNewList'));
+        blocks.push(block('reportNumbers'));
         blocks.push('-');
         blocks.push(block('reportCONS'));
         blocks.push(block('reportListItem'));
@@ -2617,6 +2626,7 @@ SpriteMorph.prototype.freshPalette = function (category) {
                     [
                         'doDeclareVariables',
                         'reportNewList',
+                        'reportNumbers',
                         'reportCONS',
                         'reportListItem',
                         'reportCDR',
@@ -7985,6 +7995,7 @@ StageMorph.prototype.blockTemplates = function (category) {
         blocks.push(block('doDeclareVariables'));
         blocks.push('=');
         blocks.push(block('reportNewList'));
+        blocks.push(block('reportNumbers'));
         blocks.push('-');
         blocks.push(block('reportCONS'));
         blocks.push(block('reportListItem'));

src/threads.js

@@ -1802,6 +1802,37 @@ Process.prototype.doShowTable = function (list) {
     new TableDialogMorph(list).popUp(this.blockReceiver().world());
 };
 
+// Process interpolated non-HOF list primitives
+
+Process.prototype.reportNumbers = function (start, end) {
+    // answer a new linked list containing an linearly ascending progression
+    // of integers beginning at start to end.
+    // this is interpolated so it can handle big ranges of numbers
+    // without blocking the UI
+
+    var dta;
+    this.assertType(start, 'number');
+    this.assertType(end, 'number');
+    if (this.context.aggregation === null) {
+        this.context.aggregation = {
+            target : new List(),
+            end : null,
+            idx : start
+        };
+        this.context.aggregation.target.isLinked = true;
+        this.context.aggregation.end = this.context.aggregation.target;
+    }
+    dta = this.context.aggregation;
+    if (dta.idx > end) {
+        this.returnValueToParentContext(dta.target.cdr());
+        return;
+    }
+    dta.end.rest = dta.target.cons(dta.idx);
+    dta.end = dta.end.rest;
+    dta.idx += 1;
+    this.pushContext();
+};
+
 // Process conditionals primitives
 
 Process.prototype.doIf = function () {