Introduce Array.form(<Enumerator>) polyfills

Introduce Array.form(<Enumerator>) polyfills

lib/std.js

@@ -3,9 +3,8 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 // https://github.com/gnh1201/welsonjs
 // 
-// WelsonJS Standard Library
+// WelsonJS Standard Library (Polyfills and shared functions)
 // 
-// Polyfills
 if (!Function.prototype.GetResource) {
     Function.prototype.GetResource = function(ResourceName) {
         if (!this.Resources) {
@@ -23,50 +22,58 @@ if (!Function.prototype.GetResource) {
     }
 }
 
-// The provided code snippet has been corrected by ChatGPT.
-// https://chat.openai.com/share/eaab056c-d265-4ee3-b355-9f29176a9caa
-// Related issues: #75 #42 #30
-if (typeof Enumerator !== "undefined") {
-    Enumerator.prototype.toArray = function() {
-        var result = [];
-        while (!this.atEnd()) {
-            var currentItem = this.item();
-            var currentItemProperties = currentItem.Properties_;
-            var itemObject = {};
-
-            var propertiesEnumerator = new Enumerator(currentItemProperties);
-            while (!propertiesEnumerator.atEnd()) {
-                var property = propertiesEnumerator.item();
-                if (typeof property.value !== "unknown") {  // The type "Unknown" is Array
-                    itemObject[property.name] = property.value;
-                } else {
-                    var arrayValues = [];
-                    var index = 0;
-                    while (true) {
-                        try {
-                            arrayValues.push(property.value(index));
-                            index++;
-                        } catch (e) {
-                            break;
-                        }
-                    }
-                    itemObject[property.name] = arrayValues;
-                }
-                propertiesEnumerator.moveNext();
-            }
-            result.push(itemObject);
-            this.moveNext();
-        }
-        
-        return result;
-    };
-}
-
-// Global APIs
 function GetResource(ResourceName) {
     return arguments.callee.caller.GetResource(ResourceName);
 }
 
+(function() {
+    var originalFrom = Array.from;
+
+    function convertToArray(v) {
+        var result = [];
+        while (!v.atEnd()) {
+            var item = v.item();
+            result.push(typeof item === "unknown" ? Array.from(item) : item);
+            v.moveNext();
+        }
+        return result;
+    }
+
+    function convertToObject(v) {
+        var obj = {};
+        var props = new Enumerator(v.Properties_);
+        while (!props.atEnd()) {
+            var prop = props.item();
+            obj[prop.name] = typeof prop.value === "unknown" ?
+                Array.from(prop.value) :
+                prop.value;
+            props.moveNext();
+        }
+        return obj;
+    }
+
+    Array.from = function(value) {
+        if (value && typeof value.item === "unknown") {
+            value = new Enumerator(value);
+        }
+
+        if (value instanceof Enumerator) {
+            return value && value.Properties_ ?
+                convertToObject(value) :
+                convertToArray(value);
+        }
+
+        return originalFrom ? originalFrom(value) : Array.prototype.slice.call(value);
+    };
+
+    Array.from.toString = function() {
+        return originalFrom.toString();
+    };
+
+    // compatible under version 0.2.7.55
+    Enumerator.prototype.toArray = Array.from;
+})();
+
 // [lib/std] the time of `sleep()' function is not accuracy #34
 function sleep(ms, callback) {
     var handler = null;
@@ -623,7 +630,7 @@ exports.alert = alert;
 exports.confirm = confirm;
 exports.prompt = prompt;
 
-exports.VERSIONINFO = "WelsonJS Standard Library (std.js) version 0.8.18";
+exports.VERSIONINFO = "WelsonJS Standard Library (std.js) version 0.8.19";
 exports.AUTHOR = "gnh1201@catswords.re.kr";
 exports.global = global;
 exports.require = global.require;