Hi
I noticed that you convert point-wise into point-free. Perhaps you could add some point-free transformations to remove redundancy in certain cases. Is that a goal of the library?
It does some transformations of th at nature, but the idea isn't to remove redundancy, its to make the code clearer. Do you have any suggestions for things it could easily do to remove redundancy? It already does a few relating to if expressions.
a suggestion for a rule: dollar eta: f $ x -> f x
That can easily be added.
Why not: ("TAG " `isPrefixOf` just_name pinfo)
That's an open bug: http://code.google.com/p/ndmitchell/issues/detail?id=109 In general, most of the hints are "replace this with this" - evaluating the new bit (even to remove easy constants) is beyond it for the moment. Some people theorised it might be too hard, non-terminating, or incorrect. As it happens this rule only fires when "TAG " is either a string literal or a list literal, and when the number is a constant, so its always safe and the guard could always be eliminated.
1) How does one actually use the CLI tool? You didn't say. It *seems* that one just feeds it a list of random filepaths, so on Mueval, say, the command would be 'hlint main.hs Mueval/*.hs' (and not, say, 'hlint mueval.cabal'). But I'm not actually sure.
The filenames are either filenames, or directories which are recursively searched, i.e cd mueval && hlint . is probably sufficient. I should document it more clearly in the manual. Thanks Neil
On Sat, Dec 20, 2008 at 3:06 PM, Neil Mitchell
Hi
I noticed that you convert point-wise into point-free. Perhaps you could add some point-free transformations to remove redundancy in certain cases. Is that a goal of the library?
It does some transformations of th at nature, but the idea isn't to remove redundancy, its to make the code clearer. Do you have any suggestions for things it could easily do to remove redundancy?
There are many simple ones, such as: f . id -> f filter true -> id map id -> id ... etc
It already does a few relating to if expressions.
Yes, like map f . map g -> map (f . g) You can find more in Transformation of Structure-Shy Programs - Applied to XPath Queries and Strategic Functions,http://www.di.uminho.pt/~mac/Publications/pepm07corrected.pdf page 4.
a suggestion for a rule: dollar eta: f $ x -> f x
That can easily be added.
Why not: ("TAG " `isPrefixOf` just_name pinfo)
That's an open bug: http://code.google.com/p/ndmitchell/issues/detail?id=109
In general, most of the hints are "replace this with this" - evaluating the new bit (even to remove easy constants) is beyond it for the moment. Some people theorised it might be too hard, non-terminating, or incorrect. As it happens this rule only fires when "TAG " is either a string literal or a list literal, and when the number is a constant, so its always safe and the guard could always be eliminated.
1) How does one actually use the CLI tool? You didn't say. It *seems* that one just feeds it a list of random filepaths, so on Mueval, say, the command would be 'hlint main.hs Mueval/*.hs' (and not, say, 'hlint mueval.cabal'). But I'm not actually sure.
The filenames are either filenames, or directories which are recursively searched, i.e cd mueval && hlint . is probably sufficient. I should document it more clearly in the manual.
Thanks
Neil
-- www.di.uminho.pt/~hpacheco
participants (2)
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Hugo Pacheco -
Neil Mitchell