diff --git a/runtime/doc/map.txt b/runtime/doc/map.txt
index 4b5dd63..4d23f4a 100644
--- a/runtime/doc/map.txt
+++ b/runtime/doc/map.txt
@@ -1009,6 +1009,20 @@
 The `mode()` function will return the state as it will be after applying the
 operator.
 
+The `mode()` function will return the state as it will be after applying the
+operator.
+
+Here is an example for using a lambda function to create a normal-mode
+operator to add quotes around text in the current line: >
+
+	nnoremap <F4> <Cmd>let &opfunc='{t ->
+				\ getline(".")
+				\ ->split("\\zs")
+				\ ->insert("\"", col("'']"))
+				\ ->insert("\"", col("''[") - 1)
+				\ ->join("")
+				\ ->setline(".")}'<CR>g@
+
 ==============================================================================
 2. Abbreviations			*abbreviations* *Abbreviations*