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-command/src/strings/char_.rs

@@ -1,12 +1,6 @@
-use indexmap::indexmap;
-use indexmap::map::IndexMap;
-use nu_engine::CallExt;
-use nu_protocol::engine::{EngineState, Stack, StateWorkingSet};
-use nu_protocol::record;
-use nu_protocol::{
-    ast::Call, engine::Command, Category, Example, IntoInterruptiblePipelineData, IntoPipelineData,
-    PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
-};
+use indexmap::{indexmap, IndexMap};
+use nu_engine::command_prelude::*;
+use nu_protocol::engine::StateWorkingSet;
 use once_cell::sync::Lazy;
 use std::sync::{atomic::AtomicBool, Arc};
 

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

@@ -1,16 +1,7 @@
-use nu_protocol::IntoPipelineData;
-use std::io::Cursor;
-use std::iter::Peekable;
-use std::str::CharIndices;
-
 use itertools::Itertools;
-use nu_engine::CallExt;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    record, Category, Example, IntoInterruptiblePipelineData, PipelineData, Range, Record,
-    ShellError, Signature, Span, Spanned, SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
+use nu_protocol::Range;
+use std::{io::Cursor, iter::Peekable, str::CharIndices};
 
 type Input<'t> = Peekable<CharIndices<'t>>;
 

crates/nu-command/src/strings/encode_decode/base64.rs

@@ -1,12 +1,18 @@
 use base64::{
-    alphabet, engine::general_purpose::NO_PAD, engine::general_purpose::PAD,
-    engine::GeneralPurpose, Engine,
+    alphabet,
+    engine::{
+        general_purpose::{NO_PAD, PAD},
+        GeneralPurpose,
+    },
+    Engine,
 };
 use nu_cmd_base::input_handler::{operate as general_operate, CmdArgument};
 use nu_engine::CallExt;
-use nu_protocol::ast::{Call, CellPath};
-use nu_protocol::engine::{EngineState, Stack};
-use nu_protocol::{PipelineData, ShellError, Span, Spanned, Value};
+use nu_protocol::{
+    ast::{Call, CellPath},
+    engine::{EngineState, Stack},
+    PipelineData, ShellError, Span, Spanned, Value,
+};
 
 pub const CHARACTER_SET_DESC: &str = "specify the character rules for encoding the input.\n\
                     \tValid values are 'standard', 'standard-no-padding', 'url-safe', 'url-safe-no-padding',\

crates/nu-command/src/strings/encode_decode/decode.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, Spanned,
-    SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct Decode;

crates/nu-command/src/strings/encode_decode/decode_base64.rs

@@ -1,9 +1,5 @@
 use super::base64::{operate, ActionType, CHARACTER_SET_DESC};
-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 DecodeBase64;

crates/nu-command/src/strings/encode_decode/encode.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, Spanned,
-    SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct Encode;

crates/nu-command/src/strings/encode_decode/encode_base64.rs

@@ -1,9 +1,5 @@
 use super::base64::{operate, ActionType, CHARACTER_SET_DESC};
-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 EncodeBase64;

crates/nu-command/src/strings/format/date.rs

@@ -1,17 +1,10 @@
+use crate::{generate_strftime_list, parse_date_from_string};
 use chrono::{DateTime, Locale, TimeZone};
+use nu_engine::command_prelude::*;
 
-use nu_engine::CallExt;
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Spanned, SyntaxShape, Type,
-    Value,
-};
 use nu_utils::locale::{get_system_locale_string, LOCALE_OVERRIDE_ENV_VAR};
 use std::fmt::{Display, Write};
 
-use crate::{generate_strftime_list, parse_date_from_string};
-
 #[derive(Clone)]
 pub struct FormatDate;
 

crates/nu-command/src/strings/format/duration.rs

@@ -1,10 +1,5 @@
 use nu_cmd_base::input_handler::{operate, CmdArgument};
-use nu_engine::CallExt;
-use nu_protocol::ast::{Call, CellPath};
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 struct Arguments {
     format_value: String,

crates/nu-command/src/strings/format/filesize.rs

@@ -1,11 +1,6 @@
 use nu_cmd_base::input_handler::{operate, CmdArgument};
-use nu_engine::CallExt;
-use nu_protocol::ast::{Call, CellPath};
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    format_filesize, Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape,
-    Type, Value,
-};
+use nu_engine::command_prelude::*;
+use nu_protocol::format_filesize;
 
 struct Arguments {
     format_value: String,

crates/nu-command/src/strings/format/format_.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 Format;

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

@@ -11,11 +11,11 @@ pub use char_::Char;
 pub use detect_columns::*;
 pub use encode_decode::*;
 pub use format::*;
-use nu_engine::CallExt;
 pub use parse::*;
 pub use split::*;
 pub use str_::*;
 
+use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{EngineState, Stack, StateWorkingSet},

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

@@ -1,13 +1,9 @@
-use std::sync::atomic::{AtomicBool, Ordering};
-use std::sync::Arc;
-
 use fancy_regex::Regex;
-use nu_engine::CallExt;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    record, Category, Example, ListStream, PipelineData, ShellError, Signature, Span, Spanned,
-    SyntaxShape, Type, Value,
+use nu_engine::command_prelude::*;
+use nu_protocol::ListStream;
+use std::sync::{
+    atomic::{AtomicBool, Ordering},
+    Arc,
 };
 
 #[derive(Clone)]

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

@@ -1,9 +1,5 @@
 use crate::grapheme_flags;
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
-};
+use nu_engine::command_prelude::*;
 use unicode_segmentation::UnicodeSegmentation;
 
 #[derive(Clone)]

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

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

crates/nu-command/src/strings/split/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 SplitCommand;

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

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

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

@@ -1,11 +1,7 @@
-use nu_engine::CallExt;
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Spanned, SyntaxShape, Type,
-    Value,
-};
+use nu_engine::command_prelude::*;
+
 use regex::Regex;
+
 #[derive(Clone)]
 pub struct SubCommand;
 

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

@@ -1,11 +1,7 @@
 use crate::grapheme_flags;
 use fancy_regex::Regex;
-use nu_engine::CallExt;
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
+
 use unicode_segmentation::UnicodeSegmentation;
 
 #[derive(Clone)]

crates/nu-command/src/strings/str_/case/capitalize.rs

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

crates/nu-command/src/strings/str_/case/downcase.rs

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

crates/nu-command/src/strings/str_/case/mod.rs

@@ -8,12 +8,8 @@ pub use downcase::SubCommand as StrDowncase;
 pub use str_::Str;
 pub use upcase::SubCommand as StrUpcase;
 
-use nu_engine::CallExt;
-
 use nu_cmd_base::input_handler::{operate as general_operate, CmdArgument};
-use nu_protocol::ast::{Call, CellPath};
-use nu_protocol::engine::{EngineState, Stack};
-use nu_protocol::{PipelineData, ShellError, Span, Value};
+use nu_engine::command_prelude::*;
 
 struct Arguments<F: Fn(&str) -> String + Send + Sync + 'static> {
     case_operation: &'static F,

crates/nu-command/src/strings/str_/case/str_.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 Str;

crates/nu-command/src/strings/str_/case/upcase.rs

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

crates/nu-command/src/strings/str_/contains.rs

@@ -1,12 +1,6 @@
 use nu_cmd_base::input_handler::{operate, CmdArgument};
-use nu_engine::CallExt;
-use nu_protocol::ast::Call;
-use nu_protocol::ast::CellPath;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::record;
-use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
+
 use nu_utils::IgnoreCaseExt;
 
 #[derive(Clone)]

crates/nu-command/src/strings/str_/distance.rs

@@ -1,11 +1,6 @@
 use nu_cmd_base::input_handler::{operate, CmdArgument};
-use nu_engine::CallExt;
-use nu_protocol::{
-    ast::{Call, CellPath},
-    engine::{Command, EngineState, Stack},
-    levenshtein_distance, record, Category, Example, PipelineData, ShellError, Signature, Span,
-    SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
+use nu_protocol::levenshtein_distance;
 
 #[derive(Clone)]
 pub struct SubCommand;

crates/nu-command/src/strings/str_/ends_with.rs

@@ -1,10 +1,6 @@
 use nu_cmd_base::input_handler::{operate, CmdArgument};
-use nu_engine::CallExt;
-use nu_protocol::ast::Call;
-use nu_protocol::ast::CellPath;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::Category;
-use nu_protocol::{Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value};
+use nu_engine::command_prelude::*;
+
 use nu_utils::IgnoreCaseExt;
 
 struct Arguments {

crates/nu-command/src/strings/str_/expand.rs

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

crates/nu-command/src/strings/str_/index_of.rs

@@ -1,13 +1,10 @@
 use crate::grapheme_flags;
-use nu_cmd_base::input_handler::{operate, CmdArgument};
-use nu_cmd_base::util;
-use nu_engine::CallExt;
-use nu_protocol::{
-    ast::{Call, CellPath},
-    engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, Range, ShellError, Signature, Span, Spanned, SyntaxShape,
-    Type, Value,
+use nu_cmd_base::{
+    input_handler::{operate, CmdArgument},
+    util,
 };
+use nu_engine::command_prelude::*;
+use nu_protocol::Range;
 use unicode_segmentation::UnicodeSegmentation;
 
 struct Arguments {

crates/nu-command/src/strings/str_/join.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, SyntaxShape, Type,
-    Value,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct StrJoin;

crates/nu-command/src/strings/str_/length.rs

@@ -1,12 +1,7 @@
-use crate::grapheme_flags;
-use crate::grapheme_flags_const;
+use crate::{grapheme_flags, grapheme_flags_const};
 use nu_cmd_base::input_handler::{operate, CmdArgument};
-use nu_engine::CallExt;
-use nu_protocol::ast::Call;
-use nu_protocol::ast::CellPath;
-use nu_protocol::engine::{Command, EngineState, Stack, StateWorkingSet};
-use nu_protocol::Category;
-use nu_protocol::{Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value};
+use nu_engine::command_prelude::*;
+use nu_protocol::engine::StateWorkingSet;
 use unicode_segmentation::UnicodeSegmentation;
 
 struct Arguments {

crates/nu-command/src/strings/str_/replace.rs

@@ -1,12 +1,6 @@
 use fancy_regex::{NoExpand, Regex};
 use nu_cmd_base::input_handler::{operate, CmdArgument};
-use nu_engine::CallExt;
-use nu_protocol::{
-    ast::{Call, CellPath},
-    engine::{Command, EngineState, Stack},
-    record, Category, Example, PipelineData, ShellError, Signature, Span, Spanned, SyntaxShape,
-    Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 struct Arguments {
     all: bool,

crates/nu-command/src/strings/str_/reverse.rs

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

crates/nu-command/src/strings/str_/starts_with.rs

@@ -1,11 +1,6 @@
 use nu_cmd_base::input_handler::{operate, CmdArgument};
-use nu_engine::CallExt;
-use nu_protocol::ast::Call;
-use nu_protocol::ast::CellPath;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::Category;
-use nu_protocol::Spanned;
-use nu_protocol::{Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value};
+use nu_engine::command_prelude::*;
+
 use nu_utils::IgnoreCaseExt;
 
 struct Arguments {

crates/nu-command/src/strings/str_/stats.rs

@@ -1,9 +1,5 @@
 use fancy_regex::Regex;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    record, Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
-};
+use nu_engine::command_prelude::*;
 use std::collections::BTreeMap;
 use std::{fmt, str};
 use unicode_segmentation::UnicodeSegmentation;

crates/nu-command/src/strings/str_/substring.rs

@@ -1,14 +1,10 @@
 use crate::grapheme_flags;
-use nu_cmd_base::input_handler::{operate, CmdArgument};
-use nu_cmd_base::util;
-use nu_engine::CallExt;
-use nu_protocol::ast::Call;
-use nu_protocol::ast::CellPath;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::Category;
-use nu_protocol::{
-    Example, PipelineData, Range, ShellError, Signature, Span, SyntaxShape, Type, Value,
+use nu_cmd_base::{
+    input_handler::{operate, CmdArgument},
+    util,
 };
+use nu_engine::command_prelude::*;
+use nu_protocol::Range;
 use std::cmp::Ordering;
 use unicode_segmentation::UnicodeSegmentation;
 

crates/nu-command/src/strings/str_/trim/trim_.rs

@@ -1,11 +1,5 @@
 use nu_cmd_base::input_handler::{operate, CmdArgument};
-use nu_engine::CallExt;
-use nu_protocol::{
-    ast::{Call, CellPath},
-    engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Spanned, SyntaxShape, Type,
-    Value,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct SubCommand;