From 373bb5644159232c6bee29b53be8b112bd0dd785 Mon Sep 17 00:00:00 2001
From: Johannes Altmanninger <aclopte@gmail.com>
Date: Sun, 12 Jan 2025 09:50:10 +0100
Subject: [PATCH] Treat '!' as super-command (it's not reserved!)

Other sigil-aliases ('[' and '_') are reserved words that cannot be
redefined as function. Only '!' is not.

Whereas several users define "function !!", I
found only one public occurrence of "function !":
https://github.com/xnuk/--/blob/5c7f87ed0788b2f83426ed52893cb582f4fb202c/fish/functions/!.fish

Note that "function !" only works if invoked as "!", "! -h" or
"! --help" or "foo | !".  In most other cases we parse it as negation.

We should probably make it a reserved word to reduce confusion.
If we do that, we should also add it to __fish_print_help, to make
"! -h" work.

For now let's rearrange the code so we can recognize "!" as
super-command. This fixes completion-based autosuggestions on "! ".
---
 src/parser_keywords.rs | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/parser_keywords.rs b/src/parser_keywords.rs
index ffc59353f..3cb110b2f 100644
--- a/src/parser_keywords.rs
+++ b/src/parser_keywords.rs
@@ -4,6 +4,7 @@ use crate::wchar::prelude::*;
 
 struct ReservedWord {
     text: &'static wstr,
+    is_reserved: bool,
     is_super_command: bool,
 }
 
@@ -11,12 +12,21 @@ macro_rules! rw {
     ( ( $text:literal ) ) => {
         ReservedWord {
             text: L!($text),
+            is_reserved: true,
             is_super_command: false,
         }
     };
     ( ( $text:literal, [subcommand] ) ) => {
         ReservedWord {
             text: L!($text),
+            is_reserved: true,
+            is_super_command: true,
+        }
+    };
+    ( ( $text:literal, [subcommand], not reserved ) ) => {
+        ReservedWord {
+            text: L!($text),
+            is_reserved: false,
             is_super_command: true,
         }
     };
@@ -29,6 +39,7 @@ macro_rules! reserved_words {
 
 // Don't forget to add any new reserved keywords to the documentation
 const RESERVED_WORDS: &[ReservedWord] = reserved_words!(
+    ("!", [subcommand], not reserved),
     ("["),
     ("_"),
     ("and", [subcommand]),
@@ -74,5 +85,5 @@ pub fn parser_keywords_is_subcommand(cmd: &impl AsRef<wstr>) -> bool {
 /// functions that change the block or command scope, like 'for', 'end' or 'command' or 'exec'.
 /// These functions may not be overloaded, so their names are reserved.
 pub fn parser_keywords_is_reserved(word: &wstr) -> bool {
-    reserved_word(word).is_some()
+    reserved_word(word).is_some_and(|reserved_word| reserved_word.is_reserved)
 }