Add more CRUD.

Transformation/Bangs/AfterBang.cs

@@ -0,0 +1,28 @@
+using System.Xml.Linq;
+using XNeedle.Parser.Elements;
+
+namespace XNeedle.Transformation.Bangs
+{
+    public class AfterBang : BangOperation
+    {
+        public override string Name => "after";
+
+        public override Context Execute(Context ctx, IEnumerable<string> arguments)
+        {
+            if (ctx.Node == null)
+            {
+                throw new ArgumentNullException("!after needs a reachable node");
+            }
+            if (arguments.Count() < 1)
+            {
+                throw new ArgumentException("!after needs at least the tag name as argument.");
+            }
+
+            var tagname = arguments.ElementAt(0);
+            var element = new XElement(tagname, "");
+            ctx.Node.AddAfterSelf(element);
+
+            return new Context{ Node = element, SLoc = ctx.SLoc.AsSynthetic(), XPathSelector = tagname};
+        }
+    }
+}

Transformation/Bangs/BeforeBang.cs

@@ -0,0 +1,28 @@
+using System.Xml.Linq;
+using XNeedle.Parser.Elements;
+
+namespace XNeedle.Transformation.Bangs
+{
+    public class BeforeBang : BangOperation
+    {
+        public override string Name => "before";
+
+        public override Context Execute(Context ctx, IEnumerable<string> arguments)
+        {
+            if (ctx.Node == null)
+            {
+                throw new ArgumentNullException("!before needs a reachable node");
+            }
+            if (arguments.Count() < 1)
+            {
+                throw new ArgumentException("!before needs at least the tag name as argument.");
+            }
+
+            var tagname = arguments.ElementAt(0);
+            var element = new XElement(tagname, "");
+            ctx.Node.AddBeforeSelf(element);
+
+            return new Context{ Node = element, SLoc = ctx.SLoc.AsSynthetic(), XPathSelector = tagname};
+        }
+    }
+}

Transformation/ContextFunctions.cs

@@ -113,7 +113,7 @@ namespace XNeedle.Transformation
         {
             if (ctx.Node == null)
             {
-                throw new ArgumentNullException("!seap needs a reachable node");
+                throw new ArgumentNullException("!swap needs a reachable node");
             }
             
             var a_node = ctx.Node.XPathSelectElement(a_select);
@@ -131,5 +131,61 @@ namespace XNeedle.Transformation
 
             return "";
         }
+
+        public static string remove(Context ctx, string select)
+        {
+            if (ctx.Node == null)
+            {
+                throw new ArgumentNullException("!remove needs a reachable node");
+            }
+            
+            // Use ToList to make the lazy/generator enumeration concrete before applying operations
+            var nodes = ctx.Node.XPathSelectElements(select).ToList();
+
+            foreach (var node in nodes)
+            {
+                node.Remove();
+            }
+
+            return "";
+        } 
+
+        public static string rename(Context ctx, string newName)
+        {
+            if (ctx.Node is null) return "";
+            var replacement = new XElement(newName, ctx.Node.Attributes(), ctx.Node.Nodes());
+            ctx.Node.ReplaceWith(replacement);
+            ctx.Node = replacement;   // update context to point to new element
+            return "";
+        }
+
+        public static string rename(Context ctx, string select, string newName)
+        {
+            if (ctx.Node is null) return "";
+
+            int atIdx = select.IndexOf('@');
+            if (atIdx >= 0)
+            {
+                // "Node@Attr" — rename an attribute
+                var elementSelect = select[..atIdx].TrimEnd();
+                var attrName = select[(atIdx + 1)..].TrimStart();
+                var target = string.IsNullOrEmpty(elementSelect)
+                    ? ctx.Node
+                    : ctx.Node.XPathSelectElement(elementSelect);
+                var attr = target?.Attribute(attrName);
+                if (attr is null) return "";
+                attr.Remove();
+                target!.SetAttributeValue(newName, attr.Value);
+            }
+            else
+            {
+                // plain XPath select — rename element
+                var target = ctx.Node.XPathSelectElement(select);
+                if (target is null) return "";
+                var replacement = new XElement(newName, target.Attributes(), target.Nodes());
+                target.ReplaceWith(replacement);
+            }
+            return "";
+        }
     }
 }