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

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

(let res_sink (DataSink 'result))
(let list (AsList
'((Uint32 '1) (String 'a))
'((Uint32 '2) (String 'b))
'((Uint32 '1) (String 'c))))

(let handler (lambda '(stream) (block '(
   (return (Map stream (lambda '(x) (Nth x '1))))
))))

(let data (LMap list handler))

(let world (Write! world res_sink (Key) data '()))
(let world (Commit! world res_sink))
(return world)
)