Support dedent with rust fn qualifiers

rc/filetype/rust.kak

@@ -147,7 +147,8 @@ define-command -hidden rust-indent-on-new-line %~
             ]
         } catch %`
             # re-indent previous line if it starts with where to match previous block
-            try %+ execute-keys -draft k <a-x> <a-k> ^\h*where\b <ret> hh <a-?> ^\h*\b(impl|fn|struct|enum|union)\b <ret> <a-S> 1<a-&> +
+            # string literal parsing within extern does not handle escape
+            try %% execute-keys -draft k <a-x> <a-k> ^\h*where\b <ret> hh <a-?> ^\h*\b(impl|(|pub\ |pub\((crate|self|super|in\ (::)?([a-zA-Z][a-zA-Z0-9_]*|_[a-zA-Z0-9_]+)(::[a-zA-Z][a-zA-Z0-9_]*|_[a-zA-Z0-9_]+)*)\)\ )(async\ |const\ )?(unsafe\ )?(extern\ ("[^"]*"\ )?)?fn|struct|enum|union)\b <ret> <a-S> 1<a-&> %
             # preserve previous line indent
             try %{ execute-keys -draft <semicolon> K <a-&> }
             # indent after lines ending with [{([].+ and move first parameter to own line
@@ -156,7 +157,7 @@ define-command -hidden rust-indent-on-new-line %~
             # XXX simplify this into a single <a-k> without s
             try %< execute-keys -draft k <a-x> s [^\h].+ <ret> <a-K> \A[-+*/&|^})<gt><lt>#] <ret> <a-K> [,<semicolon>{](\h*/[/*].*|)$ <ret> j <a-gt> >
             # indent after lines ending with {
-            try %< execute-keys -draft k <a-x> <a-k> \{$ <ret> j <a-gt> >
+            try %+ execute-keys -draft k <a-x> <a-k> \{$ <ret> j <a-gt> +
             # dedent after lines starting with . and ending with } or ) or , or ; or .await (} or ) or .await maybe with ?)
             try %_ execute-keys -draft k <a-x> <a-k> ^\h*\. <ret> <a-k> ([,<semicolon>]|(([})]|\.await)\?*))\h*$ <ret> j <a-lt> _
             # dedent after lines ending with " => {}" - part of empty match
@@ -175,12 +176,12 @@ define-command -hidden rust-indent-on-new-line %~
 ~
 
 define-command -hidden rust-indent-on-opening-curly-brace %[
-    evaluate-commands -draft -itersel %_
+    evaluate-commands -draft -itersel %~
         # align indent with opening paren when { is entered on a new line after the closing paren
         try %[ execute-keys -draft h <a-F> ) M <a-k> \A\(.*\)\h*\n\h*\{\z <ret> s \A|.\z <ret> 1<a-&> ]
         # dedent standalone { after impl and related block without any { in between
-        try %< execute-keys -draft hh <a-?> ^\h*\b(impl|fn|struct|enum|union|if|for)\b <ret> <a-K> \{ <ret> <a-semicolon> <semicolon> ll <a-x> <a-k> ^\h*\{$ <ret> <a-lt> >
-    _
+        try %@ execute-keys -draft hh <a-?> ^\h*\b(impl|(|pub\ |pub\((crate|self|super|in\ (::)?([a-zA-Z][a-zA-Z0-9_]*|_[a-zA-Z0-9_]+)(::[a-zA-Z][a-zA-Z0-9_]*|_[a-zA-Z0-9_]+)*)\)\ )(async\ |const\ )?(unsafe\ )?(extern\ ("[^"]*"\ )?)?fn|struct|enum|union|if|for)\b <ret> <a-K> \{ <ret> <a-semicolon> <semicolon> ll <a-x> <a-k> ^\h*\{$ <ret> <a-lt> @
+    ~
 ]
 
 define-command -hidden rust-indent-on-closing %~

test/indent/rust/on-open-paren/in

@@ -3,6 +3,16 @@
         T: Debug
         %( )
 
+    pub async fn foo<T>(x: T)
+    where
+        T: Debug
+        %( )
+
+    pub(in std::fmt) const unsafe extern "C" fn foo<T>(x: T)
+    where
+        T: Debug
+        %( )
+
     fn foo<T>(x: T) where T: Debug %( )
 
     impl<T> X for T

test/indent/rust/on-open-paren/out

@@ -3,6 +3,16 @@
         T: Debug
     {
 
+    pub async fn foo<T>(x: T)
+    where
+        T: Debug
+    {
+
+    pub(in std::fmt) const unsafe extern "C" fn foo<T>(x: T)
+    where
+        T: Debug
+    {
+
     fn foo<T>(x: T) where T: Debug {
 
     impl<T> X for T