1 files changed, 39 insertions, 0 deletions
diff --git a/src/nvim/event/defs.h b/src/nvim/event/defs.h
new file mode 100644
index 0000000000..5126d52241
--- /dev/null
+++ b/src/nvim/event/defs.h
@@ -0,0 +1,39 @@
+#ifndef NVIM_EVENT_DEFS_H
+#define NVIM_EVENT_DEFS_H
+
+#include <assert.h>
+#include <stdarg.h>
+
+#define EVENT_HANDLER_MAX_ARGC 4
+
+typedef void (*argv_callback)(void **argv);
+typedef struct message {
+  int priority;
+  argv_callback handler;
+  void *argv[EVENT_HANDLER_MAX_ARGC];
+} Event;
+
+#define VA_EVENT_INIT(event, p, h, a)                   \
+  do {                                                  \
+    assert(a <= EVENT_HANDLER_MAX_ARGC);                \
+    (event)->priority = p;                              \
+    (event)->handler = h;                               \
+    if (a) {                                            \
+      va_list args;                                     \
+      va_start(args, a);                                \
+      for (int i = 0; i < a; i++) {                     \
+        (event)->argv[i] = va_arg(args, void *);        \
+      }                                                 \
+      va_end(args);                                     \
+    }                                                   \
+  } while (0)
+
+static inline Event event_create(int priority, argv_callback cb, int argc, ...)
+{
+  assert(argc <= EVENT_HANDLER_MAX_ARGC);
+  Event event;
+  VA_EVENT_INIT(&event, priority, cb, argc);
+  return event;
+}
+
+#endif  // NVIM_EVENT_DEFS_H