Fixed bug with wrong line numbers in error messages. Some examples refactoring and bug fixes. (0.39.15)

examples/blocking/tk_hello.fun

@@ -0,0 +1,33 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2025 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2025-12-09
+ */
+
+// Demonstrates the Tk stdlib wrapper class using the new Tk opcodes.
+
+include <ui/tk.fun>
+
+tk = TK()
+
+tk.title("Fun + Tk GUI")
+
+tk.label("hello", "Hello, world!")
+tk.pack("hello")
+
+tk.button("ok", "OK")
+tk.pack("ok")
+
+// Enter GUI loop (no-op if built without FUN_WITH_TCLTK)
+tk.loop()
+
+/* Expected output:
+A GUI... ;)
+*/