patch 7.4.2044
Problem:    filter() and map() either require a string or defining a function.
Solution:   Support lambda, a short way to define a function that evaluates an
            expression. (Yasuhiro Matsumoto, Ken Takata)
diff --git a/src/testdir/test_alot.vim b/src/testdir/test_alot.vim
index 3074a5c..e9c8439 100644
--- a/src/testdir/test_alot.vim
+++ b/src/testdir/test_alot.vim
@@ -19,6 +19,7 @@
 source test_help_tagjump.vim
 source test_join.vim
 source test_jumps.vim
+source test_lambda.vim
 source test_lispwords.vim
 source test_matchstrpos.vim
 source test_menu.vim