feat(lua): use callable table as iterator in vim.iter (#23957)

A table passed to `vim.iter` can be a class instance with a `__call`
implementation for the iterator protocol.

1 files changed, 8 insertions, 0 deletions

diff --git a/runtime/doc/lua.txt b/runtime/doc/lua.txt
index 91d18bbe85..44682d40e5 100644
--- a/runtime/doc/lua.txt
+++ b/runtime/doc/lua.txt
@@ -2999,6 +2999,8 @@ pipeline depend on the type passed to this function:
 • Non-list tables pass both the key and value of each element
 • Function iterators pass all of the values returned by their respective
   function
+• Tables with a metatable implementing __call are treated as function
+  iterators
 
 Examples: >lua
 
@@ -3032,6 +3034,12 @@ Examples: >lua
    end)
    -- true
 
+   local rb = vim.ringbuf(3)
+   rb:push("a")
+   rb:push("b")
+   vim.iter(rb):totable()
+   -- { "a", "b" }
+
 <
 
 In addition to the |vim.iter()| function, the |vim.iter| module provides