News aggregator

Number of widgets extant and displayed varying overtime? (FRP, reactive-banana)

haskell-cafe - Wed, 01/14/2015 - 4:39am
Dear list, I want to write an application in which the set of widgets in existence, and the subset of them that is displayed, depends on user input. I am using reactive-banana. So far the simplest spec I have imagined for it is this: Initially there is just a text entry box and an empty (hence invisible) collection of labels. The user can do two things: enter the word "add", or enter an integer. Entering the word "add" causes a label to be added to the collection, but not displayed. The labels require no text content. Entering an integer N causes the first N labels to be displayed onscreen. The text entry box remains visible. I am totally baffled. In particular, the Behavior paradigm, though it is elegant and beautiful whenever I study it, I have no idea how to apply. Thank you, Jeff _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe< at >
Categories: Offsite Discussion

ocharles.hs - Wed, 01/14/2015 - 3:59am
Categories: Offsite Blogs

ocharles.hs - Wed, 01/14/2015 - 3:59am
Categories: Offsite Blogs

ParallelListComp strange behavior

haskell-cafe - Wed, 01/14/2015 - 1:04am
I am trying to use ParallelListComp and have code that compiles but only produces one value, but I am not clear why. The code is something like: gen :: (a -> b) -> [MyType] gen f = [MyType (Just []) (Just c) (Just d) Nothing | c <- f | d <- [1,2,3,4] When the gen function is used with take or any other function, only one value is returned. Is there something here that can’t desugar properly to mzip that will still compile? Note I did not test this specific code, I am just writing it here to represent the different pieces of a larger piece of real code which is below. Mike ———— Real Code ———— data Config = Config { onOffControl::Maybe [DEVICE_ON_OFF_CONTROL_BITS] , seqUpPos::[Maybe ([DEVICE_SEQ_UP_POSITION_BITS], Word16)] , seqDownPos::[Maybe ([DEVICE_SEQ_DOWN_POSITION_BITS], Word16)] , tonTimers::[Maybe ([DEVICE_TON_TIMERS_BITS], Word16)]
Categories: Offsite Discussion

Future of the boxes package--call for ideas

glasgow-user - Wed, 01/14/2015 - 1:02am
I've just taken over maintainership of the boxes package, and will be making a maintenance release shortly (as soon as I figure out how and get added to the maintainers group). The package, however, currently suffers from a paucity of bug reports (no problem) and feature requests (not so great). To keep things lively, I need a bit of help from two groups of people. If you use the package but wish it could do something more for you, I want to know about it. If you considered using the package but rejected it because it couldn't quite handle your job, I want to know about that too. I'd prefer if people would open issues and pull requests at but I will also accept requests by email. Thanks, David _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users< at >
Categories: Offsite Discussion

Difference types

Haskell on Reddit - Tue, 01/13/2015 - 8:42pm

Humor me here, I have no idea what I'm doing.

The simple algebraic types Either, (,), -> correspond to the functions +, *, ^. Is it possible to construct types that correspond to - or /?

For example suppose we wanted to find a type that corresponds to 1 - a:

D(a) = 1 - a D(a) + a = 1 D(a) * D(a) + a * D(a) = D(a) type D a = Either (D a, D a) (a, D a)

This seems to correspond to some sort of tree structure. Does this have relevance or meaning?

submitted by stonegrizzly
[link] [6 comments]
Categories: Incoming News

Magnus Therning: Thought on JavaScript

Planet Haskell - Tue, 01/13/2015 - 6:00pm

Over the holidays I’ve been reading Douglas Crockford’s excellent book JavaScript: The Good Parts. About halfway through I came to the conclusion that JavaScript is an “anti-LISP”. There are many reasons to learn LISP, but none of them is “LISP is widely used in industry.” As Eric Raymond is famous words claim, knowing LISP will make you a better programmer. On the other hand there seems to be almost no reasons to learn JavaScript. It sure doesn’t seem to teach anything that’ll make you a better programmer. The only reason I can come up with is “JavaScript is widely used in industry.”

Categories: Offsite Blogs

FP Complete is hiring: Software engineer

haskell-cafe - Tue, 01/13/2015 - 4:31pm
Hi list, FP Complete is expanding yet again! We are looking to hire for several new engineers to join our Haskell development team, both to build great new core products and in partnership with our clients to apply Haskell at a large scale. Some of our recently announced core products include the Integrated Analysis Platform, Stackage and LTS Haskell, with much more to come. If you’d like to be part of our team and shape the future of Haskell, please send a resume or CV to jobs+dev< at > Any existing work - either a running website or an open source codebase - which you can include as links be greatly appreciated as well. We will want you to start right away. Depending on your current jurisdiction, this will either be a full-time contractor position, or an employee position. This is a telecommute position: you can work from home or wherever you choose, with little or no travel. Location in North America preferred; but you will work with colleagues who are both on North American and European hou
Categories: Offsite Discussion