Make commands keywords

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

@@ -1,4 +1,5 @@
 use nu_engine::command_prelude::*;
+use nu_protocol::engine::CommandType;
 
 #[derive(Clone)]
 pub struct Break;
@@ -18,6 +19,15 @@ impl Command for Break {
             .category(Category::Core)
     }
 
+    fn extra_usage(&self) -> &str {
+        r#"This command is a parser keyword. For details, check:
+  https://www.nushell.sh/book/thinking_in_nu.html"#
+    }
+
+    fn command_type(&self) -> CommandType {
+        CommandType::Keyword
+    }
+
     fn run(
         &self,
         _engine_state: &EngineState,

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

@@ -1,4 +1,5 @@
 use nu_engine::command_prelude::*;
+use nu_protocol::engine::CommandType;
 
 #[derive(Clone)]
 pub struct Continue;
@@ -18,6 +19,14 @@ impl Command for Continue {
             .category(Category::Core)
     }
 
+    fn extra_usage(&self) -> &str {
+        r#"This command is a parser keyword. For details, check:
+  https://www.nushell.sh/book/thinking_in_nu.html"#
+    }
+
+    fn command_type(&self) -> CommandType {
+        CommandType::Keyword
+    }
     fn run(
         &self,
         _engine_state: &EngineState,

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

@@ -1,5 +1,5 @@
 use nu_engine::command_prelude::*;
-use nu_protocol::did_you_mean;
+use nu_protocol::{did_you_mean, engine::CommandType};
 
 #[derive(Clone)]
 pub struct HideEnv;
@@ -29,6 +29,15 @@ impl Command for HideEnv {
         "Hide environment variables in the current scope."
     }
 
+    fn extra_usage(&self) -> &str {
+        r#"This command is a parser keyword. For details, check:
+  https://www.nushell.sh/book/thinking_in_nu.html"#
+    }
+
+    fn command_type(&self) -> CommandType {
+        CommandType::Keyword
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

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

@@ -2,7 +2,7 @@ use nu_engine::{
     command_prelude::*, get_eval_block, get_eval_expression, get_eval_expression_with_input,
 };
 use nu_protocol::{
-    engine::StateWorkingSet,
+    engine::{CommandType, StateWorkingSet},
     eval_const::{eval_const_subexpression, eval_constant, eval_constant_with_input},
 };
 
@@ -41,6 +41,15 @@ impl Command for If {
             .category(Category::Core)
     }
 
+    fn extra_usage(&self) -> &str {
+        r#"This command is a parser keyword. For details, check:
+  https://www.nushell.sh/book/thinking_in_nu.html"#
+    }
+
+    fn command_type(&self) -> CommandType {
+        CommandType::Keyword
+    }
+
     fn is_const(&self) -> bool {
         true
     }

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

@@ -1,4 +1,5 @@
 use nu_engine::{command_prelude::*, get_eval_block};
+use nu_protocol::engine::CommandType;
 
 #[derive(Clone)]
 pub struct Loop;
@@ -20,6 +21,15 @@ impl Command for Loop {
             .category(Category::Core)
     }
 
+    fn extra_usage(&self) -> &str {
+        r#"This command is a parser keyword. For details, check:
+  https://www.nushell.sh/book/thinking_in_nu.html"#
+    }
+
+    fn command_type(&self) -> CommandType {
+        CommandType::Keyword
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

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

@@ -1,7 +1,7 @@
 use nu_engine::{
     command_prelude::*, get_eval_block, get_eval_expression, get_eval_expression_with_input,
 };
-use nu_protocol::engine::Matcher;
+use nu_protocol::engine::{CommandType, Matcher};
 
 #[derive(Clone)]
 pub struct Match;
@@ -27,6 +27,15 @@ impl Command for Match {
             .category(Category::Core)
     }
 
+    fn extra_usage(&self) -> &str {
+        r#"This command is a parser keyword. For details, check:
+  https://www.nushell.sh/book/thinking_in_nu.html"#
+    }
+
+    fn command_type(&self) -> CommandType {
+        CommandType::Keyword
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

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

@@ -1,5 +1,4 @@
 use nu_engine::{command_prelude::*, get_full_help};
-use nu_protocol::engine::CommandType;
 
 #[derive(Clone)]
 pub struct Scope;
@@ -20,10 +19,6 @@ impl Command for Scope {
         "Commands for getting info about what is in scope."
     }
 
-    fn command_type(&self) -> CommandType {
-        CommandType::Keyword
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

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

@@ -1,5 +1,5 @@
 use nu_engine::{command_prelude::*, get_eval_block, EvalBlockFn};
-use nu_protocol::engine::Closure;
+use nu_protocol::engine::{Closure, CommandType};
 
 #[derive(Clone)]
 pub struct Try;
@@ -31,6 +31,15 @@ impl Command for Try {
             .category(Category::Core)
     }
 
+    fn extra_usage(&self) -> &str {
+        r#"This command is a parser keyword. For details, check:
+  https://www.nushell.sh/book/thinking_in_nu.html"#
+    }
+
+    fn command_type(&self) -> CommandType {
+        CommandType::Keyword
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

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

@@ -1,4 +1,5 @@
 use nu_engine::{command_prelude::*, get_eval_block, get_eval_expression};
+use nu_protocol::engine::CommandType;
 
 #[derive(Clone)]
 pub struct While;
@@ -29,6 +30,15 @@ impl Command for While {
         vec!["loop"]
     }
 
+    fn extra_usage(&self) -> &str {
+        r#"This command is a parser keyword. For details, check:
+  https://www.nushell.sh/book/thinking_in_nu.html"#
+    }
+
+    fn command_type(&self) -> CommandType {
+        CommandType::Keyword
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

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

@@ -1,4 +1,5 @@
 use nu_engine::{command_prelude::*, get_eval_block, redirect_env};
+use nu_protocol::engine::CommandType;
 
 #[derive(Clone)]
 pub struct ExportEnv;
@@ -23,6 +24,15 @@ impl Command for ExportEnv {
         "Run a block and preserve its environment in a current scope."
     }
 
+    fn extra_usage(&self) -> &str {
+        r#"This command is a parser keyword. For details, check:
+  https://www.nushell.sh/book/thinking_in_nu.html"#
+    }
+
+    fn command_type(&self) -> CommandType {
+        CommandType::Keyword
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

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

@@ -2,6 +2,7 @@ use nu_engine::{
     command_prelude::*, find_in_dirs_env, get_dirs_var_from_call, get_eval_block_with_early_return,
     redirect_env,
 };
+use nu_protocol::engine::CommandType;
 use std::path::PathBuf;
 
 /// Source a file for environment variables.
@@ -28,6 +29,15 @@ impl Command for SourceEnv {
         "Source the environment from a source file into the current environment."
     }
 
+    fn extra_usage(&self) -> &str {
+        r#"This command is a parser keyword. For details, check:
+  https://www.nushell.sh/book/thinking_in_nu.html"#
+    }
+
+    fn command_type(&self) -> CommandType {
+        CommandType::Keyword
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,