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

[Tony Morris]

https://gist.github.com/tonymorris/a0e82e603d4d32597bbc/revisions

On 06/08/14 06:42, David McBride wrote:
> I took a look at your main and made some changes that might help.  I
> have not looked at your glob file at all.
>
> 1.  Rather than using length args successively in multiple if/else if
> statements, which recalculates the value, just use a case, calculate
> it once and then go from there, when you can.
>
> 2. Use let or where to make new function rather than putting them all
> inline.
>
> 3. Instead of looping the main entirely to get all of stdin, use said
> new function and have it loop itself.  You could also streamline this
> to have its own function that does not require the glob to be passed
> into each loop.
>
> 4. Use withFile instead of opening the file and then forgetting about
> the handle.  If you had enough files on the commandline, you would
> exhaust the allowable open file handles on the system.  Withfile will
> close the handle when you are done with each one.
>
> 5. Use mapM_ to get rid of the results that are returned by mapM.  It
> is also faster if you are not going to use the results anyways.
>
> 6. When you are in a monad (such as IO), you can use when instead of
> if to optionally perform a statement, and it looks a bit prettier.
>
> There are other minor things, but this is a pretty good start.
>
> Here's the resulting code (I have not run it, but it should be pretty
> close to what you had):
> https://gist.github.com/anonymous/615e48004ca2eed82d0a
>
>
> On Tue, Aug 5, 2014 at 4:08 PM, Dominik Bollmann
> <dominikbollmann at gmail.com <mailto:dominikbollmann at gmail.com>> wrote:
>
>
>     Hello Haskeller's,
>
>     I recently dived into Haskell and then wanted to practice it a bit!
>     Therefore I wrote a small program that matches UNIX-style globs. The
>     program behaves kind of like grep, just that it matches a glob and
>     not a
>     regular expression. And also, it offers only *very* rudimental
>     functionality compared to grep.
>
>     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!
>
>     Cheers, Dominik.
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