Add UNSET command. Passing ALL removes all user-defined vars, can also u...

CommandBasicIO.cs

@@ -191,6 +191,27 @@ public override void Evaluate()
         }
     }
 
+    [CommandAttribute("UNSET %")]
+    public class CommandUnset : Command
+    {
+        public CommandUnset(Match regexMatch, ExecutionContext context) : base(regexMatch, context) { }
+
+        public override void Evaluate()
+        {
+            String varname = RegexMatch.Groups[1].Value;
+
+            if (varname.ToUpper() == "ALL")
+            {
+                ParentContext.UnsetAll();
+            }
+            else
+            {
+                ParentContext.Unset(varname);
+            }
+
+            State = ExecutionState.DONE;
+            }
+    }
     [CommandAttribute("TOGGLE %")]
     public class CommandToggle : Command
     {

ExecutionContext.cs

@@ -290,6 +290,32 @@ public virtual void UnlockAll()
             if (ParentContext != null) ParentContext.UnlockAll();
         }
 
+        public virtual void Unset(String name)
+        {
+            if (Variables.ContainsKey(name.ToLower()))
+            {
+                Variables.Remove(name.ToLower());
+            }
+            else if (ParentContext != null)
+            {
+                ParentContext.Unset(name.ToLower());
+            }
+        }
+
+        public virtual void UnsetAll()
+        {
+            for( int i = 0; i < Variables.Count; i++)
+            {
+                var currvar = Variables.ElementAt(i);
+
+                if(!(currvar.Value is BoundVariable))
+                {
+                    Variables.Remove(currvar.Key);
+                }
+            }
+                if (ParentContext != null) ParentContext.UnsetAll();
+        }
+
         public bool parseNext(ref string buffer, out string cmd, ref int lineCount, out int lineStart)
         {
             lineStart = -1;