added JIT-compiled "blitz" version of FIND

HISTORY.md

@@ -29,7 +29,7 @@
     * new "get pen attribute" reporter
     * new "write" command in pen category (used to be "label" in tools)
     * new "numbers", "is empty", "map","keep", "find", "combine" and "for each" primitives in list category
-    * new JIT-compiler "blitz-HOF" primitives for "map", "keep" & "combine" via "compile"
+    * new JIT-compiler "blitz-HOF" primitives for "map", "keep", "find" & "combine" via "compile"
     * 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
@@ -82,6 +82,7 @@
 
 ### 2019-05-29
 * Threads, Objects: added "Find First" primitive to lists category
+* Blocks, Thread, Objects: added "blitz" version of FIND
 
 ### 2019-05-28
 * Maps: added various different tile hosts

snap.html

@@ -6,7 +6,7 @@
         <link rel="shortcut icon" href="src/favicon.ico">
         <script type="text/javascript" src="src/morphic.js?version=2019-05-21"></script>
         <script type="text/javascript" src="src/widgets.js?version=2019-04-05"></script>
-        <script type="text/javascript" src="src/blocks.js?version=2019-05-20"></script>
+        <script type="text/javascript" src="src/blocks.js?version=2019-05-29"></script>
         <script type="text/javascript" src="src/threads.js?version=2019-05-29"></script>
         <script type="text/javascript" src="src/objects.js?version=2019-05-29"></script>
         <script type="text/javascript" src="src/gui.js?version=2019-05-09"></script>

src/blocks.js

@@ -148,7 +148,7 @@ CustomCommandBlockMorph, SymbolMorph, ToggleButtonMorph, DialMorph*/
 
 // Global stuff ////////////////////////////////////////////////////////
 
-modules.blocks = '2019-May-20';
+modules.blocks = '2019-May-29';
 
 var SyntaxElementMorph;
 var BlockMorph;
@@ -2835,13 +2835,14 @@ BlockMorph.prototype.userMenu = function () {
     // JIT-compile HOFs - experimental
     if (
         contains(
-            ['reportMap', 'reportKeep', 'reportCombine'],
+            ['reportMap', 'reportKeep', 'reportFindFirst', 'reportCombine'],
             this.selector
         )
     ) {
         alternatives = {
             reportMap : 'reportAtomicMap',
             reportKeep : 'reportAtomicKeep',
+            reportFindFirst: 'reportAtomicFindFirst',
             reportCombine : 'reportAtomicCombine'
         };
         menu.addItem(
@@ -2855,13 +2856,19 @@ BlockMorph.prototype.userMenu = function () {
         );
     } else if (
         contains(
-            ['reportAtomicMap', 'reportAtomicKeep', 'reportAtomicCombine'],
+            [
+                'reportAtomicMap',
+                'reportAtomicKeep',
+                'reportAtomicFindFirst',
+                'reportAtomicCombine'
+            ],
             this.selector
         )
     ) {
         alternatives = {
             reportAtomicMap : 'reportMap',
             reportAtomicKeep : 'reportKeep',
+            reportAtomicFindFirst: 'reportFindFirst',
             reportAtomicCombine : 'reportCombine'
         };
         menu.addItem(

src/objects.js

@@ -1317,6 +1317,12 @@ SpriteMorph.prototype.initBlocks = function () {
             category: 'lists',
             spec: 'find first item such that %predRing in %l'
         },
+        reportAtomicFindFirst: {
+            dev: true, // not shown in palette, only accessible via relabelling
+            type: 'reporter',
+            category: 'lists',
+            spec: '%blitz find first item such that %predRing in %l'
+        },
         reportCombine: {
             type: 'reporter',
             category: 'lists',

src/threads.js

@@ -5043,6 +5043,42 @@ Process.prototype.reportAtomicKeep = function (reporter, list) {
     return new List(result);
 };
 
+Process.prototype.reportAtomicFindFirst = function (reporter, list) {
+    this.assertType(list, 'list');
+    var src = list.asArray(),
+        len = src.length,
+        func,
+        i;
+
+    // try compiling the reporter into generic JavaScript
+    // fall back to the morphic reporter if unsuccessful
+    try {
+        func = this.reportCompiled(reporter, 1); // a single expected input
+    } catch (err) {
+        console.log(err.message);
+        func = reporter;
+    }
+
+    // iterate over the data in a single frame:
+    // to do: Insert some kind of user escape mechanism
+    for (i = 0; i < len; i += 1) {
+        if (
+            invoke(
+                func,
+                new List([src[i]]),
+                null,
+                null,
+                null,
+                null,
+                this.capture(reporter) // process
+            )
+        ) {
+            return src[i];
+         }
+    }
+    return false;
+};
+
 Process.prototype.reportAtomicCombine = function (reporter, list) {
     this.assertType(list, 'list');
     var result = '',