Add a new PyList constructor

BadSingleton · BadSingleton · commit 639ba1fee517 · 2020-08-27T14:49:52.000-04:00
To build from a BorrowedReference. Assumes Ownership.
diff --git a/src/embed_tests/pyinitialize.cs b/src/embed_tests/pyinitialize.cs
@@ -25,8 +25,7 @@ public static void LoadDefaultArgs()
         {
             using (new PythonEngine())
             {
-                var argvref = new BorrowedReference(Runtime.Runtime.PySys_GetObject("argv"));
-                using(var argv = new PyList(argvref.DangerousGetAddress()))
+                using(var argv = new PyList(new BorrowedReference(Runtime.Runtime.PySys_GetObject("argv"))))
                 {
                     Assert.AreNotEqual(0, argv.Length());
                 }
@@ -39,8 +38,7 @@ public static void LoadSpecificArgs()
             var args = new[] { "test1", "test2" };
             using (new PythonEngine(args))
             {
-                var argvref = new BorrowedReference(Runtime.Runtime.PySys_GetObject("argv"));
-                using(var argv = new PyList(argvref.DangerousGetAddress()))
+                using(var argv = new PyList(new BorrowedReference(Runtime.Runtime.PySys_GetObject("argv"))))
                 {
                     Assert.AreEqual(args[0], argv[0].ToString());
                     Assert.AreEqual(args[1], argv[1].ToString());
diff --git a/src/runtime/pylist.cs b/src/runtime/pylist.cs
@@ -80,6 +80,25 @@ public PyList(PyObject[] items)
             }
         }
 
+        /// <summary>
+        /// Constructor to make a PyList from a BorrowedReference.
+        /// The list assumes ownership of the reference.
+        /// </summary>
+        /// <param name="r">The borrowed reference</param>
+        internal PyList(BorrowedReference r)
+        {
+            IntPtr addr = r.DangerousGetAddress();
+            if(!Runtime.PyList_Check(addr))
+            {
+                throw new ArgumentException("object is not a list");
+            }
+            
+            obj = addr;
+            // Take ownership.
+            Runtime.XIncref(addr);
+
+        }
+
 
         /// <summary>
         /// IsListType Method

Original file line number	Diff line number	Diff line change
`@@ -25,8 +25,7 @@ public static void LoadDefaultArgs()`
`25`	`25`	`{`
`26`	`26`	`using (new PythonEngine())`
`27`	`27`	`{`
`28`		`- var argvref = new BorrowedReference(Runtime.Runtime.PySys_GetObject("argv"));`
`29`		`- using(var argv = new PyList(argvref.DangerousGetAddress()))`
	`28`	`+ using(var argv = new PyList(new BorrowedReference(Runtime.Runtime.PySys_GetObject("argv"))))`
`30`	`29`	`{`
`31`	`30`	`Assert.AreNotEqual(0, argv.Length());`
`32`	`31`	`}`
`@@ -39,8 +38,7 @@ public static void LoadSpecificArgs()`
`39`	`38`	`var args = new[] { "test1", "test2" };`
`40`	`39`	`using (new PythonEngine(args))`
`41`	`40`	`{`
`42`		`- var argvref = new BorrowedReference(Runtime.Runtime.PySys_GetObject("argv"));`
`43`		`- using(var argv = new PyList(argvref.DangerousGetAddress()))`
	`41`	`+ using(var argv = new PyList(new BorrowedReference(Runtime.Runtime.PySys_GetObject("argv"))))`
`44`	`42`	`{`
`45`	`43`	`Assert.AreEqual(args[0], argv[0].ToString());`
`46`	`44`	`Assert.AreEqual(args[1], argv[1].ToString());`