DA> Consider the following functions: DA> readRecFile fname = DA> do ifh <- openFile fname ReadMode DA> readRecords ifh DA> readRecords ifh = DA> do x <- decodeNextRecord ifh DA> more <- isEof ifh DA> if (more == False) DA> then return [x] DA> else do rest <- readRecords ifh DA> return (x:rest) DA> They allow me to read contest of file fname into a list of data DA> structures. But "do rest <- readRecords ifh ; return (x:rest)" part makes DA> them behave non-lazily. Maybe I'm just too tired right now, but it escapes DA> me how can I write a lazy variant of those functions, so that they will DA> behave like getContents. Does anyone have a clue? I hate to followup to myself, but looks like I had to. I really was too tired and lazy version could be obtained by simple use of accumulator:
readRecFile fname = do ifh <- openFile fname ReadMode readRecords ifh []
readRecords ifh acc = do x <- decodeNextRecord ifh more <- isEof ifh if (more == False) then return (x:acc) else do readRecords ifh (x:acc)
That's it. Sorry for noice on the list. -- Dmitry Astapov //ADEpt E-mail: adept@umc.com.ua GPG KeyID/fprint: F5D7639D/CA36 E6C4 815D 434D 0498 2B08 7867 4860 F5D7 639D