Add custom state.

tests/debugging.rs

@@ -55,7 +55,7 @@ fn test_debugger_state() -> Result<(), Box<EvalAltResult>> {
             state.insert("foo".into(), false.into());
             Dynamic::from_map(state)
         },
-        |context, _, _, _, _| {
+        |mut context, _, _, _, _| {
             // Get global runtime state
             let global = context.global_runtime_state_mut();
 

tests/var_scope.rs

@@ -202,9 +202,15 @@ fn test_var_def_filter() -> Result<(), Box<EvalAltResult>> {
     let ast = engine.compile("let x = 42;")?;
     engine.run_ast(&ast)?;
 
-    engine.on_def_var(|_, info, _| match (info.name, info.nesting_level) {
-        ("x", 0 | 1) => Ok(false),
-        _ => Ok(true),
+    engine.on_def_var(|_, info, mut ctx| {
+        if ctx.tag().is::<()>() {
+            *ctx.tag_mut() = rhai::Dynamic::ONE;
+        }
+        println!("Tag = {}", ctx.tag());
+        match (info.name, info.nesting_level) {
+            ("x", 0 | 1) => Ok(false),
+            _ => Ok(true),
+        }
     });
 
     assert_eq!(