Remove parser keywords label from commands that do not need it (#8780)

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

@@ -20,15 +20,6 @@ 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 is_parser_keyword(&self) -> bool {
-        true
-    }
-
     fn run(
         &self,
         _engine_state: &EngineState,

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

@@ -20,15 +20,6 @@ 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 is_parser_keyword(&self) -> bool {
-        true
-    }
-
     fn run(
         &self,
         _engine_state: &EngineState,

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

@@ -40,15 +40,6 @@ 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 is_parser_keyword(&self) -> bool {
-        true
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

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

@@ -25,15 +25,6 @@ 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 is_parser_keyword(&self) -> bool {
-        true
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

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

@@ -29,15 +29,6 @@ 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 is_parser_keyword(&self) -> bool {
-        true
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

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

@@ -36,15 +36,6 @@ 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 is_parser_keyword(&self) -> bool {
-        true
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

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

@@ -30,15 +30,6 @@ impl Command for While {
             .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 is_parser_keyword(&self) -> bool {
-        true
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/tests/commands/alias.rs

@@ -126,6 +126,18 @@ fn alias_invalid_expression() {
     assert!(actual.err.contains("cant_alias_expression"));
 }
 
+#[test]
+fn alias_if() {
+    let actual = nu!(r#" alias spam = if true { 'spam' } else { 'eggs' }; spam "#);
+    assert_eq!(actual.out, "spam");
+}
+
+#[test]
+fn alias_match() {
+    let actual = nu!(r#" alias spam = match 3 { 1..10 => 'yes!' }; spam "#);
+    assert_eq!(actual.out, "yes!");
+}
+
 // Issue https://github.com/nushell/nushell/issues/8103
 #[test]
 fn alias_multiword_name() {

crates/nu-parser/src/parse_keywords.rs

@@ -798,8 +798,16 @@ pub fn parse_alias(
             let _equals = working_set.get_span_contents(spans[split_id + 1]);
 
             let replacement_spans = &spans[(split_id + 2)..];
+            let first_bytes = working_set.get_span_contents(replacement_spans[0]);
 
-            if is_math_expression_like(working_set, replacement_spans[0], expand_aliases_denylist) {
+            if first_bytes != b"if"
+                && first_bytes != b"match"
+                && is_math_expression_like(
+                    working_set,
+                    replacement_spans[0],
+                    expand_aliases_denylist,
+                )
+            {
                 // TODO: Maybe we need to implement a Display trait for Expression?
                 let (expr, _) = parse_expression(
                     working_set,