Block params

crates/nu-protocol/src/engine/engine_state.rs

@@ -13,7 +13,7 @@ pub struct EngineState {
 }
 
 #[derive(Debug)]
-struct ScopeFrame {
+pub struct ScopeFrame {
     vars: HashMap<Vec<u8>, VarId>,
     decls: HashMap<Vec<u8>, DeclId>,
     aliases: HashMap<Vec<u8>, Vec<Span>>,
@@ -27,6 +27,16 @@ impl ScopeFrame {
             aliases: HashMap::new(),
         }
     }
+
+    pub fn get_var(&self, var_name: &[u8]) -> Option<&VarId> {
+        self.vars.get(var_name)
+    }
+}
+
+impl Default for ScopeFrame {
+    fn default() -> Self {
+        Self::new()
+    }
 }
 
 impl Default for EngineState {
@@ -188,7 +198,7 @@ pub struct StateDelta {
     vars: Vec<Type>,              // indexed by VarId
     decls: Vec<Box<dyn Command>>, // indexed by DeclId
     blocks: Vec<Block>,           // indexed by BlockId
-    scope: Vec<ScopeFrame>,
+    pub scope: Vec<ScopeFrame>,
 }
 
 impl StateDelta {

crates/nu-protocol/src/shell_error.rs

@@ -13,7 +13,7 @@ pub enum ShellError {
     UnknownOperator(String, Span),
     ExternalNotSupported(Span),
     InternalError(String),
-    VariableNotFound(Span),
+    VariableNotFoundAtRuntime(Span),
     CantConvert(String, Span),
     DivisionByZero(Span),
 }

crates/nu-protocol/src/signature.rs

@@ -350,7 +350,7 @@ impl Command for BlockCommand {
     }
 
     fn signature(&self) -> Signature {
-        panic!("Internal error: can't get signature with 'signature', use block_id");
+        self.signature.clone()
     }
 
     fn usage(&self) -> &str {