3 files changed, 77 insertions, 72 deletions

diff --git a/src/nvim/api/buffer.c b/src/nvim/api/buffer.c
index e58035b6c7..21f7c8e931 100644
--- a/src/nvim/api/buffer.c
+++ b/src/nvim/api/buffer.c
@@ -244,78 +244,6 @@ Boolean nvim_buf_detach(uint64_t channel_id,
   return true;
 }
 
-static void buf_clear_luahl(buf_T *buf, bool force)
-{
-  if (buf->b_luahl || force) {
-    api_free_luaref(buf->b_luahl_start);
-    api_free_luaref(buf->b_luahl_window);
-    api_free_luaref(buf->b_luahl_line);
-    api_free_luaref(buf->b_luahl_end);
-  }
-  buf->b_luahl_start = LUA_NOREF;
-  buf->b_luahl_window = LUA_NOREF;
-  buf->b_luahl_line = LUA_NOREF;
-  buf->b_luahl_end = LUA_NOREF;
-}
-
-/// Unstabilized interface for defining syntax hl in lua.
-///
-/// This is not yet safe for general use, lua callbacks will need to
-/// be restricted, like textlock and probably other stuff.
-///
-/// The API on_line/nvim__put_attr is quite raw and not intended to be the
-/// final shape. Ideally this should operate on chunks larger than a single
-/// line to reduce interpreter overhead, and generate annotation objects
-/// (bufhl/virttext) on the fly but using the same representation.
-void nvim__buf_set_luahl(uint64_t channel_id, Buffer buffer,
-                         DictionaryOf(LuaRef) opts, Error *err)
-  FUNC_API_LUA_ONLY
-{
-  buf_T *buf = find_buffer_by_handle(buffer, err);
-
-  if (!buf) {
-    return;
-  }
-
-  redraw_buf_later(buf, NOT_VALID);
-  buf_clear_luahl(buf, false);
-
-  for (size_t i = 0; i < opts.size; i++) {
-    String k = opts.items[i].key;
-    Object *v = &opts.items[i].value;
-    if (strequal("on_start", k.data)) {
-      if (v->type != kObjectTypeLuaRef) {
-        api_set_error(err, kErrorTypeValidation, "callback is not a function");
-        goto error;
-      }
-      buf->b_luahl_start = v->data.luaref;
-      v->data.luaref = LUA_NOREF;
-    } else if (strequal("on_window", k.data)) {
-      if (v->type != kObjectTypeLuaRef) {
-        api_set_error(err, kErrorTypeValidation, "callback is not a function");
-        goto error;
-      }
-      buf->b_luahl_window = v->data.luaref;
-      v->data.luaref = LUA_NOREF;
-    } else if (strequal("on_line", k.data)) {
-      if (v->type != kObjectTypeLuaRef) {
-        api_set_error(err, kErrorTypeValidation, "callback is not a function");
-        goto error;
-      }
-      buf->b_luahl_line = v->data.luaref;
-      v->data.luaref = LUA_NOREF;
-    } else {
-      api_set_error(err, kErrorTypeValidation, "unexpected key: %s", k.data);
-      goto error;
-    }
-  }
-  buf->b_luahl = true;
-  return;
-error:
-  buf_clear_luahl(buf, true);
-  buf->b_luahl = false;
-}
-
 void nvim__buf_redraw_range(Buffer buffer, Integer first, Integer last,
                             Error *err)
   FUNC_API_LUA_ONLY
diff --git a/src/nvim/api/private/helpers.c b/src/nvim/api/private/helpers.c
index f1ecd732ee..e0d5862e02 100644
--- a/src/nvim/api/private/helpers.c
+++ b/src/nvim/api/private/helpers.c
@@ -1618,3 +1618,15 @@ free_exit:
   clear_virttext(&virt_text);
   return virt_text;
 }
+
+bool api_is_truthy(Object obj, const char *what, Error *err)
+{
+  if (obj.type == kObjectTypeBoolean) {
+    return obj.data.boolean;
+  } else if (obj.type == kObjectTypeInteger) {
+    return obj.data.integer;  // C semantics: non-zery int is true
+  } else {
+    api_set_error(err, kErrorTypeValidation, "%s is not an boolean", what);
+    return false;
+  }
+}
diff --git a/src/nvim/api/vim.c b/src/nvim/api/vim.c
index cb5d1e1f77..1de1472fc2 100644
--- a/src/nvim/api/vim.c
+++ b/src/nvim/api/vim.c
@@ -2702,3 +2702,68 @@ void nvim__screenshot(String path)
 {
   ui_call_screenshot(path);
 }
+
+static void clear_luahl(bool force)
+{
+  if (luahl_active || force) {
+    api_free_luaref(luahl_start);
+    api_free_luaref(luahl_win);
+    api_free_luaref(luahl_line);
+    api_free_luaref(luahl_end);
+  }
+  luahl_start = LUA_NOREF;
+  luahl_win = LUA_NOREF;
+  luahl_line = LUA_NOREF;
+  luahl_end = LUA_NOREF;
+  luahl_active = false;
+}
+
+/// Unstabilized interface for defining syntax hl in lua.
+///
+/// This is not yet safe for general use, lua callbacks will need to
+/// be restricted, like textlock and probably other stuff.
+///
+/// The API on_line/nvim__put_attr is quite raw and not intended to be the
+/// final shape. Ideally this should operate on chunks larger than a single
+/// line to reduce interpreter overhead, and generate annotation objects
+/// (bufhl/virttext) on the fly but using the same representation.
+void nvim__set_luahl(DictionaryOf(LuaRef) opts, Error *err)
+  FUNC_API_LUA_ONLY
+{
+  redraw_later(NOT_VALID);
+  clear_luahl(false);
+
+  for (size_t i = 0; i < opts.size; i++) {
+    String k = opts.items[i].key;
+    Object *v = &opts.items[i].value;
+    if (strequal("on_start", k.data)) {
+      if (v->type != kObjectTypeLuaRef) {
+        api_set_error(err, kErrorTypeValidation, "callback is not a function");
+        goto error;
+      }
+      luahl_start = v->data.luaref;
+      v->data.luaref = LUA_NOREF;
+    } else if (strequal("on_win", k.data)) {
+      if (v->type != kObjectTypeLuaRef) {
+        api_set_error(err, kErrorTypeValidation, "callback is not a function");
+        goto error;
+      }
+      luahl_win = v->data.luaref;
+      v->data.luaref = LUA_NOREF;
+    } else if (strequal("on_line", k.data)) {
+      if (v->type != kObjectTypeLuaRef) {
+        api_set_error(err, kErrorTypeValidation, "callback is not a function");
+        goto error;
+      }
+      luahl_line = v->data.luaref;
+      v->data.luaref = LUA_NOREF;
+    } else {
+      api_set_error(err, kErrorTypeValidation, "unexpected key: %s", k.data);
+      goto error;
+    }
+  }
+  luahl_active = true;
+  return;
+error:
+  clear_luahl(true);
+}