Provide better support for Go language.

1. Highlight short variable declaration operator :=.
2. 'while' is not go keyword.
3. Auto insert ')', '}', when line ends with '(' or '{'.

rc/filetype/go.kak

@@ -21,6 +21,7 @@ hook global WinSetOption filetype=go %{
     hook window InsertChar \n -group go-indent go-indent-on-new-line
     hook window InsertChar \{ -group go-indent go-indent-on-opening-curly-brace
     hook window InsertChar \} -group go-indent go-indent-on-closing-curly-brace
+    hook window InsertChar \n -group go-insert go-insert-on-new-line
 
     hook -once -always window WinSetOption filetype=.* %{ remove-hooks window go-.+ }
 }
@@ -67,6 +68,7 @@ evaluate-commands %sh{
         add-highlighter shared/go/code/ regex \b($(join "${types}" '|'))\b 0:type
         add-highlighter shared/go/code/ regex \b($(join "${values}" '|'))\b 0:value
         add-highlighter shared/go/code/ regex \b($(join "${functions}" '|'))\b 0:builtin
+        add-highlighter shared/go/code/ regex := 0:attribute
     "
 }
 
@@ -87,8 +89,6 @@ define-command -hidden go-indent-on-new-line %~
         try %{ execute-keys -draft <semicolon><c-s>k<a-x> s ^\h*\K/{2,} <ret> y<c-o>P<esc> }
         # indent after a switch's case/default statements
         try %[ execute-keys -draft k<a-x> <a-k> ^\h*(case|default).*:$ <ret> j<a-gt> ]
-        # indent after if|else|while|for
-        try %[ execute-keys -draft <semicolon><a-F>)MB <a-k> \A(if|else|while|for)\h*\(.*\)\h*\n\h*\n?\z <ret> s \A|.\z <ret> 1<a-&>1<a-space><a-gt> ]
         # deindent closing brace(s) when after cursor
         try %[ execute-keys -draft <a-x> <a-k> ^\h*[})] <ret> gh / [})] <ret> m <a-S> 1<a-&> ]
     =
@@ -104,4 +104,36 @@ define-command -hidden go-indent-on-closing-curly-brace %[
     try %[ execute-keys -itersel -draft <a-h><a-k>^\h+\}$<ret>hms\A|.\z<ret>1<a-&> ]
 ]
 
+define-command -hidden go-insert-on-new-line %[
+    evaluate-commands -no-hooks -draft -itersel %[
+        # Wisely add '}'.
+        evaluate-commands -save-regs x %[
+            # Save previous line indent in register x.
+            try %[ execute-keys -draft k<a-x>s^\h+<ret>"xy ] catch %[ reg x '' ]
+            try %[
+                # Validate previous line and that it is not closed yet.
+                execute-keys -draft k<a-x> <a-k>^<c-r>x.*\{\h*\(?\h*$<ret> J}iJ<a-x> <a-K>^<c-r>x(\)?\h*\})$<ret>
+                # Insert closing '}'.
+                execute-keys -draft o<c-r>x}<esc>
+                # Delete trailing '}' on the line below the '{'.
+                execute-keys -draft Xs\}$<ret>d
+            ]
+        ]
+
+        # Wisely add ')'.
+        evaluate-commands -save-regs x %[
+            # Save previous line indent in register x.
+            try %[ execute-keys -draft k<a-x>s^\h+<ret>"xy ] catch %[ reg x '' ]
+            try %[
+                # Validate previous line and that it is not closed yet.
+                execute-keys -draft k<a-x> <a-k>^<c-r>x.*\(\h*$<ret> J}iJ<a-x> <a-K>^<c-r>x(\)\h*\}?)$<ret>
+                # Insert closing ')'.
+                execute-keys -draft o<c-r>x)<esc>
+                # Delete trailing ')' on the line below the '('.
+                execute-keys -draft Xs\)\h*\}?\h*$<ret>d
+            ]
+        ]
+    ]
+]
+
 §

test/indent/go/deindent-function-closing-brace/out

@@ -6,7 +6,8 @@ func foo(x int) int {
 }
 
 func foo(x int) int {
-    bar()}
+    bar()
+}
 
 func foo(x int) int {
     bar()

test/indent/go/deindent-generic-closing-brace/in

@@ -1,31 +1,43 @@
+1
 {%( )}
 
+2
 {%( )
 }
 
+3
 {%( )bar()}
 
+4
 {%( )bar()
 }
 
+5
 {
     bar()%( )}
 
+6
   {
           bar()%( )}
 
+7
 {(%( ))}
 
+8
 {(%( )
 )}
 
+9
 {(%( )foo())}
 
+10
 {(%( )foo()
 )}
 
+11
 {(
     bar()%( ))}
 
+12
       {(
   bar()%( ))}

test/indent/go/deindent-generic-closing-brace/out

@@ -1,43 +1,58 @@
+1
 {
 }
 
+2
 {
     
 }
 
-{
+3
-    bar()}
-
 {
     bar()
 }
 
+4
 {
     bar()
 }
 
+5
+{
+    bar()
+}
+
+6
   {
           bar()
   }
 
+7
 {(
 )}
 
+8
 {(
     
 )}
 
+9
 {(
-    foo())}
+    foo()
+)
+}
 
+10
 {(
     foo()
 )}
 
+11
 {(
     bar()
 )}
 
+12
       {(
   bar()
       )}

test/indent/go/deindent-if-closing-brace/out

@@ -6,7 +6,8 @@ if true {
 }
 
 if true {
-    bar()}
+    bar()
+}
 
 if true {
     bar()