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Haskell Programming Language

del.icio.us/haskell - Sun, 06/01/2014 - 3:30am
Categories: Offsite Blogs

Haskell Programming Language

del.icio.us/haskell - Sun, 06/01/2014 - 3:30am
Categories: Offsite Blogs

ghc-rts.pdf

del.icio.us/haskell - Sat, 05/31/2014 - 6:37pm
Categories: Offsite Blogs

ghc-rts.pdf

del.icio.us/haskell - Sat, 05/31/2014 - 6:37pm
Categories: Offsite Blogs

IntelliJ plugin?

Haskell on Reddit - Sat, 05/31/2014 - 6:21pm

I looks like someone finally either forked the old plugin or decided to start a new one. link from IntelliJ site. Has anyone used this yet?

submitted by spitfiredd
[link] [16 comments]
Categories: Incoming News

Can't Scheme be considered a statically typed language?

Haskell on Reddit - Sat, 05/31/2014 - 1:02pm

I was thinking and I noticed one could create a language identical to Scheme with a static typing system and type inference. So why can't we say Scheme itself is a statically typed language?

5 :: Number (cons 1 nil) :: List Number (lambda (a) (+ a a)) :: Number -> Number (lambda (a) (cons a nil)) :: a -> List a

The only trouble I see would be something like below:

(lambda (a) (if a 5 (cons 1 nil)))

But I guess one could just go ahead and say it is just a sum type:

data NewType = Number | List (lambda (a) (if a 5 (cons 1 nil))) :: NewType

?

submitted by SrPeixinho
[link] [13 comments]
Categories: Incoming News

Why is the monoid operation mappend and not mop?

Haskell on Reddit - Sat, 05/31/2014 - 11:22am

I realize it's a pretty trivial thing, but it's been bugging me for a while. I searched a bit but couldn't find any historical reason for the list-centric naming of monoid functions.

submitted by Hrothen
[link] [29 comments]
Categories: Incoming News

Yesod won't install

Haskell on Reddit - Sat, 05/31/2014 - 8:05am

I tried installing Yesod, following the instructions. Unfortunately it failed with an error message:

cabal: Error: some packages failed to install: hjsmin-0.1.4.6 depends on language-javascript-0.5.13 which failed to install. language-javascript-0.5.13 failed during the configure step. The exception was: ExitFailure 1 yesod-platform-1.2.11 depends on language-javascript-0.5.13 which failed to install. yesod-static-1.2.3 depends on language-javascript-0.5.13 which failed to install.

FWIW I'm using Ubuntu 12.04 and installed Haskell with:

$ sudo apt-get install haskell-platform

Is this what is know as "dependency hell"? Would I be better off not using the apt-get package?

Also, AIUI cabal is Haskell's equvalent of Python's pip; is there a Haskell equivalent of Python's virtualenv (which let's me run multiple virtual environments, each with different packages installed)?

submitted by cabalamat
[link] [15 comments]
Categories: Incoming News

Writing functions without explicit application

Haskell on Reddit - Sat, 05/31/2014 - 7:59am

I'm trying to write a function that converts a list to a palindromic list in the following way:

> palindrate [1,2,3] [1,2,3,3,2,1] > palindrate "r/haskell" "r/haskelllleksah/r"

It is quite simple to write this in the following way:

palindrate :: [a] -> [a] palindrate l = l ++ reverse l

However recently I've become rather fond of defining functions without explicitly referring to the value they are applied to. In most situations, like the one above, it takes a few moments of thought to figure out how to do this. I have come up with the following:

palindrate :: [a] -> [a] palindrate = id &&& reverse >>> uncurry (++)

Is there a better way of doing this? And, other than the benefits derived from the programmer feeling good, is there anything to be gained from this approach?

submitted by tekn04
[link] [16 comments]
Categories: Incoming News

How much do you explicitly use category theory in your code?

Haskell on Reddit - Sat, 05/31/2014 - 6:23am

Every Haskell programmer uses category theory whether she knows it or not - map/fmap and . are two basic examples. What I want to know is, how much do you code categorically? To what end do you do so?

Personally, I'm learning it as I go along; a small project I'm working on is converting some code I have written to use algebraic type constructors (e.g. a list having a datatype F a = 1 + a * F a) and so on.

submitted by deltaSquee
[link] [51 comments]
Categories: Incoming News

ghc-rts.pdf

del.icio.us/haskell - Fri, 05/30/2014 - 9:08pm
Categories: Offsite Blogs

An alternative Haskell home page

del.icio.us/haskell - Fri, 05/30/2014 - 6:44pm
Categories: Offsite Blogs

An alternative Haskell home page

del.icio.us/haskell - Fri, 05/30/2014 - 6:44pm
Categories: Offsite Blogs

New gtk2hs 0.12.4 release

gtk2hs - Wed, 11/21/2012 - 12:56pm

Thanks to John Lato and Duncan Coutts for the latest bugfix release! The latest packages should be buildable on GHC 7.6, and the cairo package should behave a bit nicer in ghci on Windows. Thanks to all!

~d

Categories: Incoming News