Add command_prelude module (#12291)

# Description
When implementing a `Command`, one must also import all the types
present in the function signatures for `Command`. This makes it so that
we often import the same set of types in each command implementation
file. E.g., something like this:
```rust
use nu_protocol::ast::Call;
use nu_protocol::engine::{Command, EngineState, Stack};
use nu_protocol::{
    record, Category, Example, IntoInterruptiblePipelineData, IntoPipelineData, PipelineData,
    ShellError, Signature, Span, Type, Value,
};
```

This PR adds the `nu_engine::command_prelude` module which contains the
necessary and commonly used types to implement a `Command`:
```rust
// command_prelude.rs
pub use crate::CallExt;
pub use nu_protocol::{
    ast::{Call, CellPath},
    engine::{Command, EngineState, Stack},
    record, Category, Example, IntoInterruptiblePipelineData, IntoPipelineData, IntoSpanned,
    PipelineData, Record, ShellError, Signature, Span, Spanned, SyntaxShape, Type, Value,
};
```

This should reduce the boilerplate needed to implement a command and
also gives us a place to track the breadth of the `Command` API. I tried
to be conservative with what went into the prelude modules, since it
might be hard/annoying to remove items from the prelude in the future.
Let me know if something should be included or excluded.

crates/nu-cmd-lang/src/core_commands/alias.rs

@@ -1,8 +1,4 @@
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct Alias;

crates/nu-cmd-lang/src/core_commands/break_.rs

@@ -1,6 +1,4 @@
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{Category, Example, PipelineData, ShellError, Signature, Type};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct Break;

crates/nu-cmd-lang/src/core_commands/collect.rs

@@ -1,11 +1,5 @@
-use nu_engine::{get_eval_block, redirect_env, CallExt};
-use nu_protocol::ast::Call;
-
-use nu_protocol::engine::{Closure, Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, SyntaxShape, Type,
-    Value,
-};
+use nu_engine::{command_prelude::*, get_eval_block, redirect_env};
+use nu_protocol::engine::Closure;
 
 #[derive(Clone)]
 pub struct Collect;

crates/nu-cmd-lang/src/core_commands/const_.rs

@@ -1,6 +1,4 @@
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct Const;

crates/nu-cmd-lang/src/core_commands/continue_.rs

@@ -1,6 +1,4 @@
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{Category, Example, PipelineData, ShellError, Signature, Type};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct Continue;

crates/nu-cmd-lang/src/core_commands/def.rs

@@ -1,8 +1,4 @@
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct Def;

crates/nu-cmd-lang/src/core_commands/describe.rs

@@ -1,9 +1,7 @@
-use nu_engine::CallExt;
+use nu_engine::command_prelude::*;
 use nu_protocol::{
-    ast::Call,
-    engine::{Closure, Command, EngineState, Stack, StateWorkingSet},
-    record, Category, Example, IntoPipelineData, PipelineData, PipelineMetadata, Record,
-    ShellError, Signature, Type, Value,
+    engine::{Closure, StateWorkingSet},
+    PipelineMetadata,
 };
 
 #[derive(Clone)]

crates/nu-cmd-lang/src/core_commands/do_.rs

@@ -1,14 +1,7 @@
+use nu_engine::{command_prelude::*, get_eval_block_with_early_return, redirect_env};
+use nu_protocol::{engine::Closure, IoStream, ListStream, RawStream};
 use std::thread;
 
-use nu_engine::{get_eval_block_with_early_return, redirect_env, CallExt};
-use nu_protocol::ast::Call;
-
-use nu_protocol::engine::{Closure, Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, IntoSpanned, IoStream, ListStream, PipelineData, RawStream, ShellError,
-    Signature, Span, SyntaxShape, Type, Value,
-};
-
 #[derive(Clone)]
 pub struct Do;
 

crates/nu-cmd-lang/src/core_commands/echo.rs

@@ -1,10 +1,4 @@
-use nu_engine::CallExt;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape,
-    Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct Echo;

crates/nu-cmd-lang/src/core_commands/error_make.rs

@@ -1,10 +1,5 @@
-use nu_engine::CallExt;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, LabeledError, PipelineData, Record, ShellError, Signature, Span,
-    SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
+use nu_protocol::LabeledError;
 
 #[derive(Clone)]
 pub struct ErrorMake;

crates/nu-cmd-lang/src/core_commands/export.rs

@@ -1,9 +1,4 @@
-use nu_engine::get_full_help;
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack},
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Type, Value,
-};
+use nu_engine::{command_prelude::*, get_full_help};
 
 #[derive(Clone)]
 pub struct ExportCommand;

crates/nu-cmd-lang/src/core_commands/export_alias.rs

@@ -1,8 +1,4 @@
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct ExportAlias;

crates/nu-cmd-lang/src/core_commands/export_const.rs

@@ -1,8 +1,4 @@
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct ExportConst;

crates/nu-cmd-lang/src/core_commands/export_def.rs

@@ -1,8 +1,4 @@
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct ExportDef;

crates/nu-cmd-lang/src/core_commands/export_extern.rs

@@ -1,6 +1,4 @@
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct ExportExtern;

crates/nu-cmd-lang/src/core_commands/export_module.rs

@@ -1,8 +1,4 @@
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct ExportModule;

crates/nu-cmd-lang/src/core_commands/export_use.rs

@@ -1,8 +1,4 @@
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct ExportUse;

crates/nu-cmd-lang/src/core_commands/extern_.rs

@@ -1,6 +1,4 @@
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct Extern;

crates/nu-cmd-lang/src/core_commands/for_.rs

@@ -1,11 +1,5 @@
-use nu_engine::{get_eval_block, get_eval_expression, CallExt};
-use nu_protocol::ast::Call;
-
-use nu_protocol::engine::{Block, Command, EngineState, Stack};
-use nu_protocol::{
-    record, Category, Example, ListStream, PipelineData, ShellError, Signature, SyntaxShape, Type,
-    Value,
-};
+use nu_engine::{command_prelude::*, get_eval_block, get_eval_expression};
+use nu_protocol::{engine::Block, ListStream};
 
 #[derive(Clone)]
 pub struct For;

crates/nu-cmd-lang/src/core_commands/hide.rs

@@ -1,6 +1,4 @@
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct Hide;

crates/nu-cmd-lang/src/core_commands/hide_env.rs

@@ -1,10 +1,5 @@
-use nu_engine::CallExt;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    did_you_mean, Category, Example, PipelineData, ShellError, Signature, Spanned, SyntaxShape,
-    Type, Value,
-};
+use nu_engine::command_prelude::*;
+use nu_protocol::did_you_mean;
 
 #[derive(Clone)]
 pub struct HideEnv;

crates/nu-cmd-lang/src/core_commands/if_.rs

@@ -1,10 +1,9 @@
-use nu_engine::{get_eval_block, get_eval_expression, get_eval_expression_with_input, CallExt};
-use nu_protocol::ast::Call;
-
-use nu_protocol::engine::{Block, Command, EngineState, Stack, StateWorkingSet};
-use nu_protocol::eval_const::{eval_const_subexpression, eval_constant, eval_constant_with_input};
+use nu_engine::{
+    command_prelude::*, get_eval_block, get_eval_expression, get_eval_expression_with_input,
+};
 use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type, Value,
+    engine::{Block, StateWorkingSet},
+    eval_const::{eval_const_subexpression, eval_constant, eval_constant_with_input},
 };
 
 #[derive(Clone)]

crates/nu-cmd-lang/src/core_commands/ignore.rs

@@ -1,8 +1,5 @@
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack, StateWorkingSet};
-use nu_protocol::{
-    Category, Example, IoStream, PipelineData, ShellError, Signature, Span, Type, Value,
-};
+use nu_engine::command_prelude::*;
+use nu_protocol::{engine::StateWorkingSet, IoStream};
 
 #[derive(Clone)]
 pub struct Ignore;

crates/nu-cmd-lang/src/core_commands/lazy_make.rs

@@ -1,14 +1,8 @@
-use std::collections::hash_map::Entry;
-use std::collections::HashMap;
-use std::sync::{Arc, Mutex};
-
-use nu_engine::{eval_block, CallExt};
-use nu_protocol::ast::Call;
-use nu_protocol::debugger::WithoutDebug;
-use nu_protocol::engine::{Closure, Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, IntoPipelineData, LazyRecord, PipelineData, ShellError, Signature, Span,
-    Spanned, SyntaxShape, Type, Value,
+use nu_engine::{command_prelude::*, eval_block};
+use nu_protocol::{debugger::WithoutDebug, engine::Closure, LazyRecord};
+use std::{
+    collections::{hash_map::Entry, HashMap},
+    sync::{Arc, Mutex},
 };
 
 #[derive(Clone)]

crates/nu-cmd-lang/src/core_commands/let_.rs

@@ -1,9 +1,4 @@
-use nu_engine::get_eval_block;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type, Value,
-};
+use nu_engine::{command_prelude::*, get_eval_block};
 
 #[derive(Clone)]
 pub struct Let;

crates/nu-cmd-lang/src/core_commands/loop_.rs

@@ -1,10 +1,5 @@
-use nu_engine::{get_eval_block, CallExt};
-use nu_protocol::ast::Call;
-
-use nu_protocol::engine::{Block, Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type, Value,
-};
+use nu_engine::{command_prelude::*, get_eval_block};
+use nu_protocol::engine::Block;
 
 #[derive(Clone)]
 pub struct Loop;

crates/nu-cmd-lang/src/core_commands/match_.rs

@@ -1,9 +1,9 @@
-use nu_engine::{get_eval_block, get_eval_expression, get_eval_expression_with_input, CallExt};
-use nu_protocol::ast::{Call, Expr, Expression};
-
-use nu_protocol::engine::{Command, EngineState, Matcher, Stack};
+use nu_engine::{
+    command_prelude::*, get_eval_block, get_eval_expression, get_eval_expression_with_input,
+};
 use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type, Value,
+    ast::{Expr, Expression},
+    engine::Matcher,
 };
 
 #[derive(Clone)]

crates/nu-cmd-lang/src/core_commands/module.rs

@@ -1,8 +1,4 @@
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct Module;

crates/nu-cmd-lang/src/core_commands/mut_.rs

@@ -1,10 +1,4 @@
-use nu_engine::get_eval_block;
-use nu_protocol::ast::Call;
-
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type, Value,
-};
+use nu_engine::{command_prelude::*, get_eval_block};
 
 #[derive(Clone)]
 pub struct Mut;

crates/nu-cmd-lang/src/core_commands/overlay/command.rs

@@ -1,9 +1,4 @@
-use nu_engine::get_full_help;
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack},
-    Category, IntoPipelineData, PipelineData, ShellError, Signature, Type, Value,
-};
+use nu_engine::{command_prelude::*, get_full_help};
 
 #[derive(Clone)]
 pub struct Overlay;

crates/nu-cmd-lang/src/core_commands/overlay/hide.rs

@@ -1,9 +1,4 @@
-use nu_engine::CallExt;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, Spanned, SyntaxShape, Type,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct OverlayHide;

crates/nu-cmd-lang/src/core_commands/overlay/list.rs

@@ -1,8 +1,4 @@
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct OverlayList;

crates/nu-cmd-lang/src/core_commands/overlay/new.rs

@@ -1,9 +1,4 @@
-use nu_engine::CallExt;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, Spanned, SyntaxShape, Type,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct OverlayNew;

crates/nu-cmd-lang/src/core_commands/overlay/use_.rs

@@ -1,10 +1,8 @@
-use nu_engine::{find_in_dirs_env, get_dirs_var_from_call, get_eval_block, redirect_env, CallExt};
-use nu_parser::trim_quotes_str;
-use nu_protocol::ast::{Call, Expr};
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, Spanned, SyntaxShape, Type, Value,
+use nu_engine::{
+    command_prelude::*, find_in_dirs_env, get_dirs_var_from_call, get_eval_block, redirect_env,
 };
+use nu_parser::trim_quotes_str;
+use nu_protocol::ast::Expr;
 
 use std::path::Path;
 

crates/nu-cmd-lang/src/core_commands/plugin.rs

@@ -1,9 +1,4 @@
-use nu_engine::get_full_help;
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack},
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Type, Value,
-};
+use nu_engine::{command_prelude::*, get_full_help};
 
 #[derive(Clone)]
 pub struct PluginCommand;

crates/nu-cmd-lang/src/core_commands/plugin_list.rs

@@ -1,10 +1,5 @@
 use itertools::Itertools;
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack},
-    record, Category, Example, IntoInterruptiblePipelineData, PipelineData, ShellError, Signature,
-    Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct PluginList;

crates/nu-cmd-lang/src/core_commands/plugin_stop.rs

@@ -1,9 +1,4 @@
-use nu_engine::CallExt;
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Spanned, SyntaxShape, Type,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct PluginStop;

crates/nu-cmd-lang/src/core_commands/register.rs

@@ -1,6 +1,4 @@
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct Register;

crates/nu-cmd-lang/src/core_commands/return_.rs

@@ -1,9 +1,4 @@
-use nu_engine::CallExt;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct Return;

crates/nu-cmd-lang/src/core_commands/scope/aliases.rs

@@ -1,9 +1,4 @@
-use nu_engine::scope::ScopeData;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, IntoInterruptiblePipelineData, PipelineData, ShellError, Signature, Type,
-};
+use nu_engine::{command_prelude::*, scope::ScopeData};
 
 #[derive(Clone)]
 pub struct ScopeAliases;

crates/nu-cmd-lang/src/core_commands/scope/command.rs

@@ -1,9 +1,4 @@
-use nu_engine::get_full_help;
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack},
-    Category, IntoPipelineData, PipelineData, ShellError, Signature, Type, Value,
-};
+use nu_engine::{command_prelude::*, get_full_help};
 
 #[derive(Clone)]
 pub struct Scope;

crates/nu-cmd-lang/src/core_commands/scope/commands.rs

@@ -1,9 +1,4 @@
-use nu_engine::scope::ScopeData;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, IntoInterruptiblePipelineData, PipelineData, ShellError, Signature, Type,
-};
+use nu_engine::{command_prelude::*, scope::ScopeData};
 
 #[derive(Clone)]
 pub struct ScopeCommands;

crates/nu-cmd-lang/src/core_commands/scope/engine_stats.rs

@@ -1,7 +1,4 @@
-use nu_engine::scope::ScopeData;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Type};
+use nu_engine::{command_prelude::*, scope::ScopeData};
 
 #[derive(Clone)]
 pub struct ScopeEngineStats;

crates/nu-cmd-lang/src/core_commands/scope/externs.rs

@@ -1,9 +1,4 @@
-use nu_engine::scope::ScopeData;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, IntoInterruptiblePipelineData, PipelineData, ShellError, Signature, Type,
-};
+use nu_engine::{command_prelude::*, scope::ScopeData};
 
 #[derive(Clone)]
 pub struct ScopeExterns;

crates/nu-cmd-lang/src/core_commands/scope/modules.rs

@@ -1,9 +1,4 @@
-use nu_engine::scope::ScopeData;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, IntoInterruptiblePipelineData, PipelineData, ShellError, Signature, Type,
-};
+use nu_engine::{command_prelude::*, scope::ScopeData};
 
 #[derive(Clone)]
 pub struct ScopeModules;

crates/nu-cmd-lang/src/core_commands/scope/variables.rs

@@ -1,9 +1,4 @@
-use nu_engine::scope::ScopeData;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, IntoInterruptiblePipelineData, PipelineData, ShellError, Signature, Type,
-};
+use nu_engine::{command_prelude::*, scope::ScopeData};
 
 #[derive(Clone)]
 pub struct ScopeVariables;

crates/nu-cmd-lang/src/core_commands/try_.rs

@@ -1,11 +1,5 @@
-use nu_engine::{get_eval_block, CallExt, EvalBlockFn};
-use nu_protocol::ast::Call;
-
-use nu_protocol::engine::{Block, Closure, Command, EngineState, Stack};
-use nu_protocol::{
-    record, Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span,
-    SyntaxShape, Type, Value,
-};
+use nu_engine::{command_prelude::*, get_eval_block, EvalBlockFn};
+use nu_protocol::engine::{Block, Closure};
 
 #[derive(Clone)]
 pub struct Try;

crates/nu-cmd-lang/src/core_commands/use_.rs

@@ -1,10 +1,7 @@
-use nu_engine::{find_in_dirs_env, get_dirs_var_from_call, get_eval_block, redirect_env};
-use nu_protocol::ast::{Call, Expr, Expression};
-
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type, Value,
+use nu_engine::{
+    command_prelude::*, find_in_dirs_env, get_dirs_var_from_call, get_eval_block, redirect_env,
 };
+use nu_protocol::ast::{Expr, Expression};
 
 #[derive(Clone)]
 pub struct Use;

crates/nu-cmd-lang/src/core_commands/version.rs

@@ -1,8 +1,5 @@
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack, StateWorkingSet};
-use nu_protocol::{
-    Category, Example, IntoPipelineData, PipelineData, Record, ShellError, Signature, Type, Value,
-};
+use nu_engine::command_prelude::*;
+use nu_protocol::engine::StateWorkingSet;
 use shadow_rs::shadow;
 
 shadow!(build);

crates/nu-cmd-lang/src/core_commands/while_.rs

@@ -1,10 +1,5 @@
-use nu_engine::{get_eval_block, get_eval_expression, CallExt};
-use nu_protocol::ast::Call;
-
-use nu_protocol::engine::{Block, Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type, Value,
-};
+use nu_engine::{command_prelude::*, get_eval_block, get_eval_expression};
+use nu_protocol::engine::Block;
 
 #[derive(Clone)]
 pub struct While;

crates/nu-cmd-lang/src/default_context.rs

@@ -1,6 +1,5 @@
-use nu_protocol::engine::{EngineState, StateWorkingSet};
-
 use crate::*;
+use nu_protocol::engine::{EngineState, StateWorkingSet};
 
 pub fn create_default_context() -> EngineState {
     let mut engine_state = EngineState::new();

crates/nu-cmd-lang/src/example_support.rs

@@ -1,12 +1,11 @@
 use itertools::Itertools;
-use nu_protocol::debugger::WithoutDebug;
+use nu_engine::command_prelude::*;
 use nu_protocol::{
     ast::{Block, RangeInclusion},
-    engine::{EngineState, Stack, StateDelta, StateWorkingSet},
-    Example, PipelineData, Signature, Span, Type, Value,
+    debugger::WithoutDebug,
+    engine::{StateDelta, StateWorkingSet},
 };
-use std::collections::HashSet;
-use std::sync::Arc;
+use std::{collections::HashSet, sync::Arc};
 
 pub fn check_example_input_and_output_types_match_command_signature(
     example: &Example,