1 files changed, 17 insertions, 0 deletions
diff --git a/src/nvim/highlight_defs.h b/src/nvim/highlight_defs.h
index 3518c8bdcc..0790793c94 100644
--- a/src/nvim/highlight_defs.h
+++ b/src/nvim/highlight_defs.h
@@ -8,6 +8,8 @@
 typedef int32_t RgbValue;
 
 /// Highlighting attribute bits.
+///
+/// sign bit should not be used here, as it identifies invalid highlight
 typedef enum {
   HL_INVERSE     = 0x01,
   HL_BOLD        = 0x02,
@@ -152,4 +154,19 @@ EXTERN RgbValue normal_fg INIT(= -1);
 EXTERN RgbValue normal_bg INIT(= -1);
 EXTERN RgbValue normal_sp INIT(= -1);
 
+typedef enum {
+  kHlUnknown,
+  kHlUI,
+  kHlSyntax,
+  kHlTerminal,
+  kHlCombine,
+} HlKind;
+
+typedef struct {
+  HlAttrs attr;
+  HlKind kind;
+  int id1;
+  int id2;
+} HlEntry;
+
 #endif  // NVIM_HIGHLIGHT_DEFS_H