runtime(odin): update syntax, indent

- syntax: highlight attributes, e.g. @static, @(static), @(someattribute ....)
- indent: fix incorrect case: indent if previous case: has oneliner as `if ... do ...`

closes: #21067

Signed-off-by: Maxim Kim <habamax@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/indent/odin.vim

@@ -4,7 +4,7 @@ vim9script
 # Language: Odin
 # Maintainer: Maxim Kim <habamax@gmail.com>
 # Website: https://github.com/habamax/vim-odin
-# Last Change: 2026-06-28
+# Last Change: 2026 Aug 17
 
 if exists("b:did_indent")
     finish
@@ -109,7 +109,9 @@ def GetOdinIndent(lnum: number): number
         endfor
     elseif pline =~ '{[^{]*}\s*$' && line !~ '^\s*[})]\s*$' # https://github.com/habamax/vim-odin/issues/2
         indent = pindent
-    elseif line !~ '^\s*}' && pline =~ '^\s*\%(if\|for\).*\s\+do\%(\s\+\|$\)' # https://github.com/habamax/vim-odin/issues/15
+    elseif line !~ '^\s*}'
+            && line !~ '^\s*case\s\+.\{-}:'
+            && pline =~ '^\s*\%(if\|for\).*\s\+do\%(\s\+\|$\)' # https://github.com/habamax/vim-odin/issues/15
         indent = pindent
     elseif pline =~ '^\s*}\s*$' # https://github.com/habamax/vim-odin/issues/3
         # Find line with opening { and check if there is a label:

runtime/indent/testdir/odin.in

@@ -1317,7 +1317,7 @@ switch f {
 case .A:
 fmt.println("HITHER")
 case .B:
-fmt.println("NEVER")
+if true do fmt.println("NEVER")
 case .C:
 fmt.println("FOREVER")
 }

runtime/indent/testdir/odin.ok

@@ -1317,7 +1317,7 @@ implicit_selector_expression :: proc() {
     case .A:
         fmt.println("HITHER")
     case .B:
-        fmt.println("NEVER")
+        if true do fmt.println("NEVER")
     case .C:
         fmt.println("FOREVER")
     }

runtime/syntax/odin.vim

@@ -4,7 +4,7 @@ vim9script
 # Language: Odin
 # Maintainer: Maxim Kim <habamax@gmail.com>
 # Website: https://github.com/habamax/vim-odin
-# Last Change: 2026-06-01
+# Last Change: 2026 Aug 16
 
 if exists("b:current_syntax")
   finish
@@ -55,11 +55,13 @@ syntax match odinEscape display contained /\\\([abefnrtv\\'"]\|\o\{3}\|x\x\{2}\|
 
 syntax match odinProcedure "\v<\w*>(\s*::\s*proc)@="
 
-syntax match odinAttribute "@\ze\<\w\+\>" display
-syntax region odinAttribute
+syntax match odinAttribute "@" display nextgroup=odinAttributeName,odinAttributeBraces
+syntax match odinAttributeName "\<\w\+\>" display contained
+syntax region odinAttributeBraces
       \ matchgroup=odinAttribute
-      \ start="@\ze(" end="\ze)"
+      \ start="(\w\+" end=")"
       \ transparent oneline
+      \ contained
 
 syntax match odinInteger "\v-?<[0-9]+%(_[0-9]+)*>" display
 syntax match odinFloat "\v-?<[0-9]+%(_[0-9]+)*%(\.[0-9]+%(_[0-9]+)*)%([eE][+-]=[0-9]+%(_[0-9]+)*)=" display
@@ -98,13 +100,14 @@ highlight def link odinBlockComment Comment
 
 highlight def link odinTodo Todo
 
-highlight def link odinAttribute Statement
+highlight def link odinAttribute PreProc
+highlight def link odinAttributeName odinAttribute
 highlight def link odinType Type
 highlight def link odinBool Boolean
 highlight def link odinNull Constant
 highlight def link odinUninitialized Constant
-highlight def link odinInteger Number
 highlight def link odinFloat Float
+highlight def link odinInteger Number
 highlight def link odinHex Number
 highlight def link odinOct Number
 highlight def link odinBin Number