1 files changed, 18 insertions, 10 deletions
diff --git a/runtime/lua/vim/shared.lua b/runtime/lua/vim/shared.lua
index ff89acc524..631dd04c35 100644
--- a/runtime/lua/vim/shared.lua
+++ b/runtime/lua/vim/shared.lua
@@ -4,7 +4,7 @@
 -- test-suite. If, in the future, Nvim itself is used to run the test-suite
 -- instead of "vanilla Lua", these functions could move to src/nvim/lua/vim.lua
 
-local vim = {}
+local vim = vim or {}
 
 --- Returns a deep copy of the given object. Non-table objects are copied as
 --- in a typical Lua assignment, whereas table objects are copied recursively.
@@ -228,16 +228,24 @@ end
 
 --- Extends a list-like table with the values of another list-like table.
 ---
---NOTE: This *mutates* dst!
---@see |extend()|
+--- NOTE: This mutates dst!
+---
+--@see |vim.tbl_extend()|
 ---
---@param dst The list which will be modified and appended to.
---@param src The list from which values will be inserted.
-function vim.list_extend(dst, src)
-  assert(type(dst) == 'table', "dst must be a table")
-  assert(type(src) == 'table', "src must be a table")
-  for _, v in ipairs(src) do
-    table.insert(dst, v)
+--@param dst list which will be modified and appended to.
+--@param src list from which values will be inserted.
+--@param start Start index on src. defaults to 1
+--@param finish Final index on src. defaults to #src
+--@returns dst
+function vim.list_extend(dst, src, start, finish)
+  vim.validate {
+    dst = {dst, 't'};
+    src = {src, 't'};
+    start = {start, 'n', true};
+    finish = {finish, 'n', true};
+  }
+  for i = start or 1, finish or #src do
+    table.insert(dst, src[i])
   end
   return dst
 end