ydb/yql/essentials/tests/s-expressions/suites/InMem/Fold.yqls

(
#comment
(let config (DataSource 'config))

(let res_sink (DataSink 'result))
(let doFold (lambda '(list) (Fold list (List (TypeOf list)) (lambda '(item state) (Append state item)))))
(let world (Write! world res_sink (Key) (Apply doFold (AsList (String '"1") (String '"2") (String '"3") (String '"4"))) '('('type))))
(let world (Write! world res_sink (Key) (Apply doFold (AsList '((String '"1") (String '"a")) '((String '"2") (String '"b")))) '('('type))))
(let world (Write! world res_sink (Key) (Apply doFold (AsList (AsStruct '('"x" (String '"1"))) (AsStruct '('"x" (String '"2"))))) '('('type))))
(let world (Commit! world res_sink))
(return world)
)