Remove lifetime from eval state

crates/nu-engine/src/eval.rs

@@ -29,7 +29,8 @@ pub fn eval_operator(op: &Expression) -> Result<Operator, ShellError> {
 }
 
 fn eval_call(state: &State, call: &Call) -> Result<Value, ShellError> {
-    let decl = state.parser_state.get_decl(call.decl_id);
+    let parser_state = state.parser_state.borrow();
+    let decl = parser_state.get_decl(call.decl_id);
     if let Some(block_id) = decl.body {
         let state = state.enter_scope();
         for (arg, param) in call
@@ -44,7 +45,8 @@ fn eval_call(state: &State, call: &Call) -> Result<Value, ShellError> {
 
             state.add_var(var_id, result);
         }
-        let block = state.parser_state.get_block(block_id);
+        let parser_state = state.parser_state.borrow();
+        let block = parser_state.get_block(block_id);
         eval_block(&state, block)
     } else if decl.signature.name == "let" {
         let var_id = call.positional[0]
@@ -91,14 +93,15 @@ fn eval_call(state: &State, call: &Call) -> Result<Value, ShellError> {
         let result = eval_expression(state, cond)?;
         match result {
             Value::Bool { val, span } => {
+                let parser_state = state.parser_state.borrow();
                 if val {
-                    let block = state.parser_state.get_block(then_block);
+                    let block = parser_state.get_block(then_block);
                     let state = state.enter_scope();
                     eval_block(&state, block)
                 } else if let Some(else_case) = else_case {
                     if let Some(else_expr) = else_case.as_keyword() {
                         if let Some(block_id) = else_expr.as_block() {
-                            let block = state.parser_state.get_block(block_id);
+                            let block = parser_state.get_block(block_id);
                             let state = state.enter_scope();
                             eval_block(&state, block)
                         } else {
@@ -129,7 +132,8 @@ fn eval_call(state: &State, call: &Call) -> Result<Value, ShellError> {
         let block = call.positional[0]
             .as_block()
             .expect("internal error: expected block");
-        let block = state.parser_state.get_block(block);
+        let parser_state = state.parser_state.borrow();
+        let block = parser_state.get_block(block);
 
         let state = state.enter_scope();
         let start_time = Instant::now();
@@ -152,7 +156,8 @@ fn eval_call(state: &State, call: &Call) -> Result<Value, ShellError> {
         let block = call.positional[2]
             .as_block()
             .expect("internal error: expected block");
-        let block = state.parser_state.get_block(block);
+        let parser_state = state.parser_state.borrow();
+        let block = parser_state.get_block(block);
 
         let state = state.enter_scope();
 
@@ -176,15 +181,15 @@ fn eval_call(state: &State, call: &Call) -> Result<Value, ShellError> {
             span: call.positional[0].span,
         })
     } else if decl.signature.name == "vars" {
-        state.parser_state.print_vars();
+        state.parser_state.borrow().print_vars();
         Ok(Value::Nothing {
             span: call.positional[0].span,
         })
     } else if decl.signature.name == "decls" {
-        state.parser_state.print_decls();
+        state.parser_state.borrow().print_decls();
         Ok(Value::Nothing { span: call.head })
     } else if decl.signature.name == "blocks" {
-        state.parser_state.print_blocks();
+        state.parser_state.borrow().print_blocks();
         Ok(Value::Nothing { span: call.head })
     } else if decl.signature.name == "stack" {
         state.print_stack();
@@ -229,7 +234,8 @@ pub fn eval_expression(state: &State, expr: &Expression) -> Result<Value, ShellE
         }
 
         Expr::Subexpression(block_id) => {
-            let block = state.parser_state.get_block(*block_id);
+            let parser_state = state.parser_state.borrow();
+            let block = parser_state.get_block(*block_id);
 
             let state = state.enter_scope();
             eval_block(&state, block)

crates/nu-engine/src/state.rs

@@ -3,19 +3,19 @@ use std::{cell::RefCell, collections::HashMap, rc::Rc};
 
 use crate::{value::Value, ShellError};
 
-pub struct State<'a> {
+pub struct State {
-    pub parser_state: &'a ParserState,
+    pub parser_state: Rc<RefCell<ParserState>>,
     pub stack: Stack,
 }
 
-impl<'a> State<'a> {
+impl State {
     pub fn get_var(&self, var_id: VarId) -> Result<Value, ShellError> {
         self.stack.get_var(var_id)
     }
 
-    pub fn enter_scope(&self) -> State<'a> {
+    pub fn enter_scope(&self) -> State {
         Self {
-            parser_state: self.parser_state,
+            parser_state: self.parser_state.clone(),
             stack: self.stack.clone().enter_scope(),
         }
     }

src/main.rs

@@ -26,7 +26,7 @@ fn main() -> std::io::Result<()> {
         ParserState::merge_delta(&mut *parser_state.borrow_mut(), delta);
 
         let state = nu_engine::State {
-            parser_state: &*parser_state.borrow(),
+            parser_state: parser_state.clone(),
             stack: nu_engine::Stack::new(),
         };
 
@@ -88,7 +88,7 @@ fn main() -> std::io::Result<()> {
                     ParserState::merge_delta(&mut *parser_state.borrow_mut(), delta);
 
                     let state = nu_engine::State {
-                        parser_state: &*parser_state.borrow(),
+                        parser_state: parser_state.clone(),
                         stack: stack.clone(),
                     };