[Haskell-beginners] A first try
jaredhance at gmail.com
Fri Jun 24 16:51:26 CEST 2011
Okay, I'm going to give some more stylistic notes.
> 8. let combined = parseArgs Args
You don't need this one.
> Lines 9 - 11
> let sep = separateFiles args
> fl = head (fst sep)
> showResultsFile fl (snd sep)
let (f, s) = separateFiles args
showResultsFile (head f) s
> Lines 19-20
> processFile fl flags =
> mapM dispatch [(flag, fl) | flag <- flags]
Why isn't this on one line? Its not particularly long.
> Lines 25-31
> dispatch (fl, fn) = do
> handle <- openFile fl ReadMode
> contents <- hGetContents handle
> let cnt = getCounter fn
> res = cnt contents
> hClose handle
> return res
dispatch (fl, fn) = do contents <- withFile fl ReadMode hGetContents
return $ getCounter fn contents
However also note that you are defining a function of the form
f :: (a, b) -> c
rather than the better
f :: a -> b -> c
Naturally, I see that the reason is that you are calling it from mapM.
However, I would define dispatch as a curried function, and then use
`curry dispatch` in your mapM. It makes dispatch much cleaner.
> Lines 36-44
> a bunch of putStrLn
You could also use mapM_ putStrLn [list of string to put out], removing
duplicate uses of putStrLn here.
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