Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
We don’t allow questions seeking recommendations for books, tools, software libraries, and more. You can edit the question so it can be answered with facts and citations.
Closed 8 years ago.
Improve this question
I'd like to quickly and correctly reduce functions to point free form in Haskell. I'd prefer to produce fairly readable outcomes. How should I go about this?
There is actually a program called "pointfree"
Do this
cabal install pointfree
then this at the command line
> pointfree "\x -> x+1"
(1 +)
Warning- although some pointfree outcomes are wonderful, others are pretty scary....
The Haskell wiki covers tools for pointfree refactoring here. It mainly covers Lambdabot, an IRC bot that does pointfree and pointful refactoring:
#pl \x y -> EQ == compare x y
((EQ ==) .) . compare
[1] Example from http://ircbrowse.net/browse/haskell?id=19908612×tamp=1421726397#t1421726397
Related
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
We don’t allow questions seeking recommendations for books, tools, software libraries, and more. You can edit the question so it can be answered with facts and citations.
Closed 2 years ago.
Improve this question
I have a binary string. I want to split it into head and tail. The close candidate is from bytestring is:
uncons :: ByteString -> Maybe (Word8, ByteString)
But I want to split it such that the head would be, say, of type Word16 instead of Word8. Or Word32. Or anything else.
How can I do that?
There are many deserialization libraries available. For one that sounds like it is a particularly close match to your mental model, check out binary's Get. It is not really in scope to give a Big List of all the available ones, but a quick search on Hackage should give you many other choices to consider.
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
We don’t allow questions seeking recommendations for books, tools, software libraries, and more. You can edit the question so it can be answered with facts and citations.
Closed 5 years ago.
Improve this question
I'm looking for something similar to Python's os.path.expandvars in Haskell, i.e., a FilePath -> IO FilePath function that is
Cross-platform (supports both Windows %VAR% and Unix $VAR styles)
Standard (I don't want to write my own function for that).
Example:
> expandVars "$HOME/foo/bar"
"/home/someuser/foo/bar"
I've searched on Hoogle, Hayoo and Google but found nothing, which is surprising given the number of cross-platform Haskell tools. The closest I found is this Unix-only implementation. Perhaps there is some project which implements this as a subroutine?
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
We don’t allow questions seeking recommendations for books, tools, software libraries, and more. You can edit the question so it can be answered with facts and citations.
Closed 6 years ago.
Improve this question
I'd like to learn how to port Haskell code to Frege. Are there any projects that have already been ported and serve as good examples?
Almost all of the existing library code (i.e. Prelude, Data, etc.) have been ported. Also things like QuickCheck, with almost no adaptions.
An interesting case is Data.HashMap which has the same interface as in Haskell, but the implementation relies on Java arrays.
Things to watch out for: unsupported GHC extensions, Strings/Text, code that uses foreign functions (that is, C).
In such cases the Frege analogue of Haskell is usually slightly different, or misses features. Examples would be JSON support and parser combinator libraries (Data.MicroParsec).
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
We don’t allow questions seeking recommendations for books, tools, software libraries, and more. You can edit the question so it can be answered with facts and citations.
Closed 5 years ago.
Improve this question
If I want to write proofs and algorithms/semantics using Coq on a Haskell program. How can I translate from Haskell to Coq to do this?
It seems that there are tools to translate OCaml programs. But how about Haskell?
The main issue I see in such a translation is that Haskell programs (as well as Ocaml ones) can perform any kind of recursion algorithm, and might contain loops.
In Coq, there is no build-in notion of loops, and any recursive function has to terminate, and be explicit why it terminates.
To the best of my knowledge, there is no such tool at the moment.
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
We don’t allow questions seeking recommendations for books, tools, software libraries, and more. You can edit the question so it can be answered with facts and citations.
Closed 7 years ago.
Improve this question
Are there any lists of tricky Haskell exercises that use monads in surprising ways floating around? I'm most interested in simple 'work out what this line of code does' or 'do this in point free using this monad' type questions.
Try to figure out why the programs here terminate.
It's not about monads, but these 20 intermediate haskell exercises could make your evening.
http://www.haskell.org/haskellwiki/Blow_your_mind
I don't know what you call tricky, but if you've never tied the knot you should try to make iterative depth first search using knot tying (and make sure it terminates cleanly if no solution is found!).