Re: [Haskell-beginners] Feedback on my first, small project (piece).

On 08/06/2014 12:46 AM, Henk-Jan van Tuyl wrote:

On Tue, 05 Aug 2014 22:08:51 +0200, Dominik Bollmann wrote:

:

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The code is available on github: https://github.com/bollmann/Globber When writing the program I tried to satisfy the specification as given at: http://www.scs.stanford.edu/14sp-cs240h/labs/lab1.html. This Lab material btw. also inspired me to try writing such a program :-).

In order to improve my programming in Haskell, I would love to hear feedback from you guys on this first small project of mine. Any comments regarding style, used idioms, as well as general and specific code improvements are highly appreciated. Thanks! :

You could change matchGlob' :: GlobPattern -> String -> Bool matchGlob' glob string | null glob && null string = True | null glob && not (null string) = False | null string && glob == "*" = True | null string && glob /= "*" = False matchGlob' (p:ps) (s:sx) | p == '?' = matchGlob' ps sx | p == '\\' = matchEscapedChar ps (s:sx) | p == '*' = matchStar ps (s:sx) | p == '[' = matchSet (p:ps) (s:sx) | otherwise = p == s && matchGlob' ps sx

to: matchGlob' :: GlobPattern -> String -> Bool matchGlob' [] string = null string matchGlob' glob [] = glob == "*" matchGlob' ('?':ps) (s:sx) = matchGlob' ps sx matchGlob' ('\\':ps) sx = matchEscapedChar ps sx matchGlob' ('*':ps) sx = matchStar ps sx matchGlob' ('[':ps) sx = matchSet ('[':ps) sx matchGlob' (p:ps) (s:sx) = p == s && matchGlob' ps sx

(not tested)

In function buildCharChoices, you have written where isRange chars = if (length chars) == 3 && (chars !! 1) == '-' then True else False , this can be simplified to where isRange chars = length chars == 3 && chars !! 1 == '-'

Regards, Henk-Jan van Tuyl

isRange could also be written as isRange [_, '-', _] = True isRange _ = False which I think makes it more obvious what you're looking for -- Mateusz K.