WIP

crates/nu-cli/src/completions.rs

@@ -1,10 +1,8 @@
-use std::{cell::RefCell, rc::Rc};
-
 use nu_engine::eval_block;
 use nu_parser::{flatten_block, parse};
 use nu_protocol::{
-    engine::{EngineState, EvaluationContext, Stack, StateWorkingSet},
-    PipelineData, Value,
+    engine::{EngineState, Stack, StateWorkingSet},
+    PipelineData,
 };
 use reedline::Completer;
 

crates/nu-cli/src/validation.rs

@@ -1,5 +1,3 @@
-use std::{cell::RefCell, rc::Rc};
-
 use nu_parser::{parse, ParseError};
 use nu_protocol::engine::{EngineState, StateWorkingSet};
 use reedline::{ValidationResult, Validator};

crates/nu-command/src/conversions/into/binary.rs

@@ -1,6 +1,6 @@
 use nu_protocol::{
     ast::Call,
-    engine::{Command, EngineState, EvaluationContext, Stack},
+    engine::{Command, EngineState, Stack},
     Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
 };
 
@@ -26,8 +26,8 @@ impl Command for SubCommand {
 
     fn run(
         &self,
-        engine_state: &EngineState,
-        stack: &mut Stack,
+        _engine_state: &EngineState,
+        _stack: &mut Stack,
         call: &Call,
         input: PipelineData,
     ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {

crates/nu-command/src/conversions/into/command.rs

@@ -1,7 +1,7 @@
 use nu_engine::get_full_help;
 use nu_protocol::{
     ast::Call,
-    engine::{Command, EngineState, EvaluationContext, Stack},
+    engine::{Command, EngineState, Stack},
     IntoPipelineData, PipelineData, Signature, Value,
 };
 

crates/nu-command/src/conversions/into/filesize.rs

@@ -1,6 +1,6 @@
 use nu_protocol::{
     ast::Call,
-    engine::{Command, EngineState, EvaluationContext, Stack},
+    engine::{Command, EngineState, Stack},
     Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
 };
 

crates/nu-command/src/conversions/into/int.rs

@@ -1,6 +1,6 @@
 use nu_protocol::{
     ast::Call,
-    engine::{Command, EngineState, EvaluationContext, Stack},
+    engine::{Command, EngineState, Stack},
     Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
 };
 

crates/nu-command/src/core_commands/alias.rs

@@ -1,6 +1,6 @@
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
-use nu_protocol::{PipelineData, Signature, SyntaxShape, Value};
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{PipelineData, Signature, SyntaxShape};
 
 #[derive(Clone)]
 pub struct Alias;
@@ -28,7 +28,7 @@ impl Command for Alias {
         &self,
         _engine_state: &EngineState,
         _stack: &mut Stack,
-        call: &Call,
+        _call: &Call,
         _input: PipelineData,
     ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
         Ok(PipelineData::new())

crates/nu-command/src/core_commands/def.rs

@@ -1,6 +1,6 @@
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
-use nu_protocol::{PipelineData, Signature, SyntaxShape, Value};
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{PipelineData, Signature, SyntaxShape};
 
 #[derive(Clone)]
 pub struct Def;
@@ -29,7 +29,7 @@ impl Command for Def {
         &self,
         _engine_state: &EngineState,
         _stack: &mut Stack,
-        call: &Call,
+        _call: &Call,
         _input: PipelineData,
     ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
         Ok(PipelineData::new())

crates/nu-command/src/core_commands/do_.rs

@@ -1,6 +1,6 @@
 use nu_engine::{eval_block, CallExt};
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
+use nu_protocol::engine::{Command, EngineState, Stack};
 use nu_protocol::{PipelineData, Signature, SyntaxShape, Value};
 
 #[derive(Clone)]
@@ -80,6 +80,6 @@ impl Command for Do {
                 )
             }
         }
-        eval_block(&engine_state, &mut stack, block, input)
+        eval_block(engine_state, &mut stack, block, input)
     }
 }

crates/nu-command/src/core_commands/export_def.rs

@@ -1,6 +1,6 @@
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
-use nu_protocol::{PipelineData, Signature, SyntaxShape, Value};
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{PipelineData, Signature, SyntaxShape};
 
 #[derive(Clone)]
 pub struct ExportDef;
@@ -29,7 +29,7 @@ impl Command for ExportDef {
         &self,
         _engine_state: &EngineState,
         _stack: &mut Stack,
-        call: &Call,
+        _call: &Call,
         _input: PipelineData,
     ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
         Ok(PipelineData::new())

crates/nu-command/src/core_commands/for_.rs

@@ -1,6 +1,6 @@
 use nu_engine::{eval_block, eval_expression};
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
+use nu_protocol::engine::{Command, EngineState, Stack};
 use nu_protocol::{Example, IntoPipelineData, PipelineData, Signature, Span, SyntaxShape, Value};
 
 #[derive(Clone)]
@@ -56,7 +56,7 @@ impl Command for For {
             .expect("internal error: expected block");
 
         let engine_state = engine_state.clone();
-        let mut stack = stack.enter_scope();
+        let stack = stack.enter_scope();
 
         match values {
             Value::List { vals, span } => Ok(vals

crates/nu-command/src/core_commands/help.rs

@@ -1,6 +1,6 @@
 use nu_protocol::{
     ast::Call,
-    engine::{Command, EngineState, EvaluationContext, Stack},
+    engine::{Command, EngineState, Stack},
     span, Example, IntoPipelineData, PipelineData, ShellError, Signature, Spanned, SyntaxShape,
     Value,
 };

crates/nu-command/src/core_commands/hide.rs

@@ -1,6 +1,6 @@
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
-use nu_protocol::{PipelineData, Signature, SyntaxShape, Value};
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{PipelineData, Signature, SyntaxShape};
 
 #[derive(Clone)]
 pub struct Hide;
@@ -22,7 +22,7 @@ impl Command for Hide {
         &self,
         _engine_state: &EngineState,
         _stack: &mut Stack,
-        call: &Call,
+        _call: &Call,
         _input: PipelineData,
     ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
         Ok(PipelineData::new())

crates/nu-command/src/core_commands/if_.rs

@@ -1,6 +1,6 @@
 use nu_engine::{eval_block, eval_expression};
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
+use nu_protocol::engine::{Command, EngineState, Stack};
 use nu_protocol::{IntoPipelineData, PipelineData, ShellError, Signature, SyntaxShape, Value};
 
 #[derive(Clone)]
@@ -41,23 +41,23 @@ impl Command for If {
 
         let result = eval_expression(engine_state, stack, cond)?;
         match result {
-            Value::Bool { val, span } => {
+            Value::Bool { val, .. } => {
                 if val {
                     let block = engine_state.get_block(then_block);
                     let mut stack = stack.enter_scope();
-                    eval_block(&engine_state, &mut stack, block, input)
+                    eval_block(engine_state, &mut stack, block, input)
                 } 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 = engine_state.get_block(block_id);
                             let mut stack = stack.enter_scope();
-                            eval_block(&engine_state, &mut stack, block, input)
+                            eval_block(engine_state, &mut stack, block, input)
                         } else {
-                            eval_expression(&engine_state, stack, else_expr)
+                            eval_expression(engine_state, stack, else_expr)
                                 .map(|x| x.into_pipeline_data())
                         }
                     } else {
-                        eval_expression(&engine_state, stack, else_case)
+                        eval_expression(engine_state, stack, else_case)
                             .map(|x| x.into_pipeline_data())
                     }
                 } else {

crates/nu-command/src/core_commands/let_.rs

@@ -1,7 +1,7 @@
 use nu_engine::eval_expression;
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
-use nu_protocol::{PipelineData, Signature, SyntaxShape, Value};
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{PipelineData, Signature, SyntaxShape};
 
 #[derive(Clone)]
 pub struct Let;
@@ -40,7 +40,7 @@ impl Command for Let {
             .as_keyword()
             .expect("internal error: missing keyword");
 
-        let rhs = eval_expression(&engine_state, stack, keyword_expr)?;
+        let rhs = eval_expression(engine_state, stack, keyword_expr)?;
 
         //println!("Adding: {:?} to {}", rhs, var_id);
 

crates/nu-command/src/core_commands/module.rs

@@ -1,6 +1,6 @@
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
-use nu_protocol::{PipelineData, Signature, SyntaxShape, Value};
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{PipelineData, Signature, SyntaxShape};
 
 #[derive(Clone)]
 pub struct Module;
@@ -28,7 +28,7 @@ impl Command for Module {
         &self,
         _engine_state: &EngineState,
         _stack: &mut Stack,
-        call: &Call,
+        _call: &Call,
         _input: PipelineData,
     ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
         Ok(PipelineData::new())

crates/nu-command/src/core_commands/source.rs

@@ -1,7 +1,7 @@
 use nu_engine::{eval_block, CallExt};
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
-use nu_protocol::{PipelineData, ShellError, Signature, SyntaxShape, Value};
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{PipelineData, ShellError, Signature, SyntaxShape};
 
 /// Source a file for environment variables.
 #[derive(Clone)]

crates/nu-command/src/core_commands/use_.rs

@@ -1,6 +1,6 @@
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
-use nu_protocol::{PipelineData, Signature, SyntaxShape, Value};
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{PipelineData, Signature, SyntaxShape};
 
 #[derive(Clone)]
 pub struct Use;
@@ -22,7 +22,7 @@ impl Command for Use {
         &self,
         _engine_state: &EngineState,
         _stack: &mut Stack,
-        call: &Call,
+        _call: &Call,
         _input: PipelineData,
     ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
         Ok(PipelineData::new())

crates/nu-command/src/env/let_env.rs

@@ -1,7 +1,7 @@
 use nu_engine::eval_expression;
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
-use nu_protocol::{PipelineData, Signature, SyntaxShape, Value};
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{PipelineData, Signature, SyntaxShape};
 
 #[derive(Clone)]
 pub struct LetEnv;

crates/nu-command/src/example_test.rs

@@ -1,10 +1,8 @@
-use std::{cell::RefCell, rc::Rc};
-
 use nu_engine::eval_block;
 use nu_parser::parse;
 use nu_protocol::{
-    engine::{Command, EngineState, EvaluationContext, Stack, StateWorkingSet},
-    PipelineData, Value,
+    engine::{Command, EngineState, Stack, StateWorkingSet},
+    PipelineData,
 };
 
 use super::{From, Into, Split};

crates/nu-command/src/experimental/git.rs

@@ -1,5 +1,5 @@
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
+use nu_protocol::engine::{Command, EngineState, Stack};
 use nu_protocol::{IntoPipelineData, PipelineData, Signature, Value};
 
 #[derive(Clone)]

crates/nu-command/src/experimental/git_checkout.rs

@@ -1,6 +1,6 @@
 use nu_engine::eval_expression;
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
+use nu_protocol::engine::{Command, EngineState, Stack};
 use nu_protocol::{IntoPipelineData, PipelineData, Signature, SyntaxShape, Value};
 
 #[derive(Clone)]

crates/nu-command/src/experimental/list_git_branches.rs

@@ -4,9 +4,9 @@ use std::process::Command as ProcessCommand;
 use std::process::Stdio;
 
 use nu_protocol::ast::Call;
+use nu_protocol::engine::Command;
 use nu_protocol::engine::EngineState;
 use nu_protocol::engine::Stack;
-use nu_protocol::engine::{Command, EvaluationContext};
 use nu_protocol::IntoPipelineData;
 use nu_protocol::PipelineData;
 use nu_protocol::{Signature, Value};
@@ -46,6 +46,7 @@ impl Command for ListGitBranches {
 
                 let s = String::from_utf8_lossy(&val).to_string();
 
+                #[allow(clippy::needless_collect)]
                 let lines: Vec<_> = s
                     .lines()
                     .filter_map(|x| {

crates/nu-command/src/filesystem/cd.rs

@@ -1,7 +1,7 @@
 use nu_engine::CallExt;
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
-use nu_protocol::{PipelineData, Signature, SyntaxShape, Value};
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{PipelineData, Signature, SyntaxShape};
 
 #[derive(Clone)]
 pub struct Cd;

crates/nu-command/src/filesystem/cp.rs

@@ -5,8 +5,8 @@ use super::util::get_interactive_confirmation;
 use nu_engine::CallExt;
 use nu_path::canonicalize_with;
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
-use nu_protocol::{PipelineData, ShellError, Signature, SyntaxShape, Value};
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{PipelineData, ShellError, Signature, SyntaxShape};
 
 use crate::filesystem::util::FileStructure;
 

crates/nu-command/src/filesystem/ls.rs

@@ -1,7 +1,7 @@
 use chrono::{DateTime, Utc};
 use nu_engine::eval_expression;
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
+use nu_protocol::engine::{Command, EngineState, Stack};
 use nu_protocol::{IntoPipelineData, PipelineData, Signature, SyntaxShape, Value};
 
 #[derive(Clone)]

crates/nu-command/src/filesystem/mkdir.rs

@@ -3,10 +3,8 @@ use std::env::current_dir;
 
 use nu_engine::CallExt;
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
-use nu_protocol::{
-    IntoPipelineData, PipelineData, ShellError, Signature, SyntaxShape, Value, ValueStream,
-};
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{IntoPipelineData, PipelineData, ShellError, Signature, SyntaxShape, Value};
 
 #[derive(Clone)]
 pub struct Mkdir;

crates/nu-command/src/filesystem/mv.rs

@@ -4,8 +4,8 @@ use std::path::{Path, PathBuf};
 use super::util::get_interactive_confirmation;
 use nu_engine::CallExt;
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
-use nu_protocol::{PipelineData, ShellError, Signature, SyntaxShape, Value};
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{PipelineData, ShellError, Signature, SyntaxShape};
 
 #[derive(Clone)]
 pub struct Mv;

crates/nu-command/src/filesystem/rm.rs

@@ -7,10 +7,8 @@ use super::util::get_interactive_confirmation;
 
 use nu_engine::CallExt;
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
-use nu_protocol::{
-    IntoPipelineData, PipelineData, ShellError, Signature, SyntaxShape, Value, ValueStream,
-};
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{IntoPipelineData, PipelineData, ShellError, Signature, SyntaxShape, Value};
 
 #[derive(Clone)]
 pub struct Rm;

crates/nu-command/src/filesystem/touch.rs

@@ -2,8 +2,8 @@ use std::fs::OpenOptions;
 
 use nu_engine::CallExt;
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
-use nu_protocol::{PipelineData, ShellError, Signature, SyntaxShape, Value};
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{PipelineData, ShellError, Signature, SyntaxShape};
 
 #[derive(Clone)]
 pub struct Touch;

crates/nu-command/src/filters/each.rs

@@ -1,6 +1,6 @@
 use nu_engine::eval_block;
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
+use nu_protocol::engine::{Command, EngineState, Stack};
 use nu_protocol::{Example, IntoPipelineData, PipelineData, Signature, Span, SyntaxShape, Value};
 
 #[derive(Clone)]
@@ -64,7 +64,7 @@ impl Command for Each {
 
         let numbered = call.has_flag("numbered");
         let engine_state = engine_state.clone();
-        let mut stack = stack.clone();
+        let stack = stack.clone();
         let span = call.head;
 
         match input {

crates/nu-command/src/filters/get.rs

@@ -1,7 +1,7 @@
 use nu_engine::CallExt;
 use nu_protocol::ast::{Call, CellPath};
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
-use nu_protocol::{IntoPipelineData, PipelineData, Signature, SyntaxShape, Value};
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{IntoPipelineData, PipelineData, Signature, SyntaxShape};
 
 #[derive(Clone)]
 pub struct Get;

crates/nu-command/src/filters/length.rs

@@ -1,5 +1,5 @@
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
+use nu_protocol::engine::{Command, EngineState, Stack};
 use nu_protocol::{IntoPipelineData, PipelineData, Signature, Value};
 
 #[derive(Clone)]

crates/nu-command/src/filters/lines.rs

@@ -1,9 +1,6 @@
-use std::cell::RefCell;
-use std::rc::Rc;
-
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
-use nu_protocol::{IntoPipelineData, PipelineData, ShellError, Signature, Value, ValueStream};
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{IntoPipelineData, PipelineData, ShellError, Signature, Value};
 
 #[derive(Clone)]
 pub struct Lines;
@@ -30,7 +27,6 @@ impl Command for Lines {
         call: &Call,
         input: PipelineData,
     ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
-        let span = call.head;
         match input {
             #[allow(clippy::needless_collect)]
             // Collect is needed because the string may not live long enough for

crates/nu-command/src/filters/select.rs

@@ -1,6 +1,6 @@
 use nu_engine::CallExt;
 use nu_protocol::ast::{Call, CellPath};
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
+use nu_protocol::engine::{Command, EngineState, Stack};
 use nu_protocol::{
     Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
 };

crates/nu-command/src/filters/where_.rs

@@ -1,6 +1,6 @@
 use nu_engine::eval_expression;
 use nu_protocol::ast::{Call, Expr, Expression};
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
+use nu_protocol::engine::{Command, EngineState, Stack};
 use nu_protocol::{IntoPipelineData, PipelineData, ShellError, Signature, SyntaxShape, Value};
 
 #[derive(Clone)]
@@ -52,7 +52,7 @@ impl Command for Where {
                     }
                 })
                 .into_pipeline_data()),
-            PipelineData::Value(Value::List { vals, span }) => Ok(vals
+            PipelineData::Value(Value::List { vals, .. }) => Ok(vals
                 .into_iter()
                 .filter(move |value| {
                     stack.add_var(var_id, value.clone());

crates/nu-command/src/filters/wrap.rs

@@ -1,6 +1,6 @@
 use nu_engine::CallExt;
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
+use nu_protocol::engine::{Command, EngineState, Stack};
 use nu_protocol::{IntoPipelineData, PipelineData, Signature, SyntaxShape, Value};
 
 #[derive(Clone)]

crates/nu-command/src/formats/from/command.rs

@@ -1,6 +1,6 @@
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
-use nu_protocol::{PipelineData, ShellError, Signature, Value};
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{PipelineData, ShellError, Signature};
 
 #[derive(Clone)]
 pub struct From;

crates/nu-command/src/formats/from/json.rs

@@ -1,5 +1,5 @@
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
+use nu_protocol::engine::{Command, EngineState, Stack};
 use nu_protocol::{Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, Value};
 
 #[derive(Clone)]

crates/nu-command/src/strings/build_string.rs

@@ -1,6 +1,6 @@
 use nu_engine::eval_expression;
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
+use nu_protocol::engine::{Command, EngineState, Stack};
 use nu_protocol::{
     Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
 };

crates/nu-command/src/strings/size.rs

@@ -3,7 +3,7 @@ extern crate unicode_segmentation;
 use unicode_segmentation::UnicodeSegmentation;
 
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
+use nu_protocol::engine::{Command, EngineState, Stack};
 use nu_protocol::{
     Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, Type, Value,
 };

crates/nu-command/src/strings/split/chars.rs

@@ -1,6 +1,6 @@
 use nu_protocol::{
     ast::Call,
-    engine::{Command, EngineState, EvaluationContext, Stack},
+    engine::{Command, EngineState, Stack},
     Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 

crates/nu-command/src/strings/split/column.rs

@@ -1,7 +1,7 @@
 use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
-    engine::{Command, EngineState, EvaluationContext, Stack},
+    engine::{Command, EngineState, Stack},
     IntoPipelineData, PipelineData, ShellError, Signature, Span, Spanned, SyntaxShape, Type, Value,
 };
 

crates/nu-command/src/strings/split/command.rs

@@ -1,7 +1,7 @@
 use nu_engine::get_full_help;
 use nu_protocol::{
     ast::Call,
-    engine::{Command, EngineState, EvaluationContext, Stack},
+    engine::{Command, EngineState, Stack},
     IntoPipelineData, PipelineData, Signature, Value,
 };
 

crates/nu-command/src/strings/split/row.rs

@@ -1,7 +1,7 @@
 use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
-    engine::{Command, EngineState, EvaluationContext, Stack},
+    engine::{Command, EngineState, Stack},
     IntoPipelineData, PipelineData, ShellError, Signature, Span, Spanned, SyntaxShape, Type, Value,
 };
 

crates/nu-command/src/system/benchmark.rs

@@ -2,8 +2,8 @@ use std::time::Instant;
 
 use nu_engine::eval_block;
 use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
-use nu_protocol::{PipelineData, Signature, SyntaxShape, Value};
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{PipelineData, Signature, SyntaxShape};
 
 #[derive(Clone)]
 pub struct Benchmark;
@@ -39,7 +39,8 @@ impl Command for Benchmark {
 
         let mut stack = stack.enter_scope();
         let start_time = Instant::now();
-        eval_block(&engine_state, &mut stack, block, PipelineData::new())?;
+        eval_block(engine_state, &mut stack, block, PipelineData::new())?.into_value();
+
         let end_time = Instant::now();
         println!("{} ms", (end_time - start_time).as_millis());
         Ok(PipelineData::new())

crates/nu-command/src/system/ps.rs

@@ -1,6 +1,6 @@
 use nu_protocol::{
     ast::Call,
-    engine::{Command, EngineState, EvaluationContext, Stack},
+    engine::{Command, EngineState, Stack},
     Example, IntoPipelineData, PipelineData, ShellError, Signature, Value,
 };
 use sysinfo::{ProcessExt, System, SystemExt};

crates/nu-command/src/system/run_external.rs

@@ -1,21 +1,15 @@
 use std::borrow::Cow;
-use std::cell::RefCell;
 use std::collections::HashMap;
 use std::env;
 use std::io::{BufRead, BufReader, Write};
 use std::process::{ChildStdin, Command as CommandSys, Stdio};
-use std::rc::Rc;
 use std::sync::mpsc;
 
 use nu_protocol::engine::{EngineState, Stack};
-use nu_protocol::{
-    ast::{Call, Expression},
-    engine::{Command, EvaluationContext},
-    ShellError, Signature, SyntaxShape, Value,
-};
-use nu_protocol::{IntoPipelineData, PipelineData, Span, Spanned, ValueStream};
+use nu_protocol::{ast::Call, engine::Command, ShellError, Signature, SyntaxShape, Value};
+use nu_protocol::{IntoPipelineData, PipelineData, Span, Spanned};
 
-use nu_engine::{eval_expression, CallExt};
+use nu_engine::CallExt;
 
 const OUTPUT_BUFFER_SIZE: usize = 8192;
 

crates/nu-command/src/system/sys.rs

@@ -1,6 +1,6 @@
 use nu_protocol::{
     ast::Call,
-    engine::{Command, EngineState, EvaluationContext, Stack},
+    engine::{Command, EngineState, Stack},
     Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, Value,
 };
 use sysinfo::{ComponentExt, DiskExt, NetworkExt, ProcessorExt, System, SystemExt, UserExt};

crates/nu-command/src/viewers/griddle.rs

@@ -2,7 +2,7 @@ use lscolors::{LsColors, Style};
 use nu_engine::CallExt;
 use nu_protocol::{
     ast::{Call, PathMember},
-    engine::{Command, EngineState, EvaluationContext, Stack},
+    engine::{Command, EngineState, Stack},
     IntoPipelineData, PipelineData, Signature, Span, SyntaxShape, Value,
 };
 use nu_term_grid::grid::{Alignment, Cell, Direction, Filling, Grid, GridOptions};

crates/nu-command/src/viewers/table.rs

@@ -1,5 +1,5 @@
 use nu_protocol::ast::{Call, PathMember};
-use nu_protocol::engine::{Command, EngineState, EvaluationContext, Stack};
+use nu_protocol::engine::{Command, EngineState, Stack};
 use nu_protocol::{IntoPipelineData, PipelineData, ShellError, Signature, Span, Value};
 use nu_table::StyledString;
 use std::collections::HashMap;

crates/nu-engine/src/call_ext.rs

@@ -1,6 +1,6 @@
 use nu_protocol::{
     ast::Call,
-    engine::{EngineState, EvaluationContext, Stack},
+    engine::{EngineState, Stack},
     ShellError,
 };
 

crates/nu-engine/src/documentation.rs

@@ -1,8 +1,5 @@
 use itertools::Itertools;
-use nu_protocol::{
-    engine::{EngineState, EvaluationContext},
-    Example, Signature, Span, Value,
-};
+use nu_protocol::{engine::EngineState, Example, Signature, Span, Value};
 use std::collections::HashMap;
 
 const COMMANDS_DOCS_DIR: &str = "docs/commands";

crates/nu-engine/src/eval.rs

@@ -1,5 +1,5 @@
 use nu_protocol::ast::{Block, Call, Expr, Expression, Operator, Statement};
-use nu_protocol::engine::{EngineState, EvaluationContext, Stack};
+use nu_protocol::engine::{EngineState, Stack};
 use nu_protocol::{
     IntoPipelineData, PipelineData, Range, ShellError, Span, Spanned, Type, Unit, Value,
 };
@@ -55,7 +55,7 @@ fn eval_call(
                 decl.signature().required_positional.len()
                     + decl.signature().optional_positional.len(),
             ) {
-                let result = eval_expression(&engine_state, &mut stack, arg)?;
+                let result = eval_expression(engine_state, &mut stack, arg)?;
                 rest_items.push(result);
             }
 
@@ -82,7 +82,7 @@ fn eval_call(
                 for call_named in &call.named {
                     if call_named.0.item == named.long {
                         if let Some(arg) = &call_named.1 {
-                            let result = eval_expression(&engine_state, &mut stack, arg)?;
+                            let result = eval_expression(engine_state, &mut stack, arg)?;
 
                             stack.add_var(var_id, result);
                         } else {

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

@@ -1,6 +1,6 @@
-use crate::{ast::Call, value::Value, BlockId, Example, PipelineData, ShellError, Signature};
+use crate::{ast::Call, BlockId, Example, PipelineData, ShellError, Signature};
 
-use super::{EngineState, EvaluationContext, Stack};
+use super::{EngineState, Stack};
 
 pub trait Command: Send + Sync + CommandClone {
     fn name(&self) -> &str;

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

@@ -1,7 +1,7 @@
 use super::Command;
 use crate::{ast::Block, BlockId, DeclId, Example, Signature, Span, Type, VarId};
 use core::panic;
-use std::{collections::HashMap, slice::Iter};
+use std::collections::HashMap;
 
 #[derive(Clone)]
 pub struct EngineState {
@@ -167,7 +167,7 @@ impl EngineState {
 
     pub fn print_contents(&self) {
         for (contents, _, _) in self.file_contents.iter() {
-            let string = String::from_utf8_lossy(&contents);
+            let string = String::from_utf8_lossy(contents);
             println!("{}", string);
         }
     }
@@ -204,7 +204,7 @@ impl EngineState {
 
     pub fn get_span_contents(&self, span: &Span) -> &[u8] {
         for (contents, start, finish) in &self.file_contents {
-            if span.start >= *start && span.start <= *finish {
+            if span.start >= *start && span.end <= *finish {
                 return &contents[(span.start - start)..(span.end - start)];
             }
         }
@@ -262,7 +262,11 @@ impl EngineState {
     }
 
     pub fn next_span_start(&self) -> usize {
-        self.file_contents.len()
+        if let Some((_, _, last)) = self.file_contents.last() {
+            *last
+        } else {
+            0
+        }
     }
 
     pub fn files(&self) -> impl Iterator<Item = &(String, usize, usize)> {
@@ -494,7 +498,13 @@ impl<'a> StateWorkingSet<'a> {
     }
 
     pub fn next_span_start(&self) -> usize {
-        self.permanent_state.next_span_start() + self.delta.file_contents.len()
+        let permanent_span_start = self.permanent_state.next_span_start();
+
+        if let Some((_, _, last)) = self.delta.file_contents.last() {
+            permanent_span_start + *last
+        } else {
+            permanent_span_start
+        }
     }
 
     pub fn global_span_offset(&self) -> usize {
@@ -550,7 +560,7 @@ impl<'a> StateWorkingSet<'a> {
         let permanent_end = self.permanent_state.next_span_start();
         if permanent_end <= span.start {
             for (contents, start, finish) in &self.delta.file_contents {
-                if (span.start >= *start) && (span.start <= *finish) {
+                if (span.start >= *start) && (span.end <= *finish) {
                     return &contents[(span.start - permanent_end)..(span.end - permanent_end)];
                 }
             }

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

@@ -1,5 +1,5 @@
 use super::EngineState;
-use std::{cell::RefCell, collections::HashMap, rc::Rc};
+use std::collections::HashMap;
 
 use crate::{Example, ShellError, Signature, Value, VarId};
 

crates/nu-protocol/src/signature.rs

@@ -1,13 +1,10 @@
 use crate::ast::Call;
 use crate::engine::Command;
-use crate::engine::CommandClone;
 use crate::engine::EngineState;
-use crate::engine::EvaluationContext;
 use crate::engine::Stack;
 use crate::BlockId;
 use crate::PipelineData;
 use crate::SyntaxShape;
-use crate::Value;
 use crate::VarId;
 
 #[derive(Debug, Clone, PartialEq, Eq)]

src/main.rs

@@ -1,4 +1,4 @@
-use std::{cell::RefCell, io::Write, rc::Rc};
+use std::io::Write;
 
 use dialoguer::{
     console::{Style, Term},
@@ -12,7 +12,7 @@ use nu_engine::eval_block;
 use nu_parser::parse;
 use nu_protocol::{
     ast::Call,
-    engine::{EngineState, EvaluationContext, Stack, StateWorkingSet},
+    engine::{EngineState, Stack, StateWorkingSet},
     IntoPipelineData, PipelineData, ShellError, Value,
 };
 use reedline::{Completer, CompletionActionHandler, DefaultPrompt, LineBuffer, Prompt};
@@ -268,23 +268,22 @@ fn update_prompt<'prompt>(
         return nu_prompt as &dyn Prompt;
     }
 
-    let (block, delta) = {
-        let mut working_set = StateWorkingSet::new(&engine_state);
+    let block = {
+        let mut working_set = StateWorkingSet::new(engine_state);
         let (output, err) = parse(&mut working_set, None, prompt_command.as_bytes(), false);
         if let Some(err) = err {
             report_error(&working_set, &err);
             return default_prompt as &dyn Prompt;
         }
-        (output, working_set.render())
+        output
     };
 
     let mut stack = stack.clone();
 
-    let evaluated_prompt = match eval_block(&engine_state, &mut stack, &block, PipelineData::new())
-    {
+    let evaluated_prompt = match eval_block(engine_state, &mut stack, &block, PipelineData::new()) {
         Ok(pipeline_data) => pipeline_data.collect_string(),
         Err(err) => {
-            let working_set = StateWorkingSet::new(&engine_state);
+            let working_set = StateWorkingSet::new(engine_state);
             report_error(&working_set, &err);
             return default_prompt as &dyn Prompt;
         }