###Melchior

Melchior, the Haskell based functional reactive programming framework for making rich, responsive web applications.

###getting it going and all that good stuff

so to run this you basically need to get a copy of the uhc from here then if you don't have it already grab npm

so ostensibly you should now be able to sudo ./install and it will install all the package dependencies and add the melchior bin file to /usr/bin, but there's still something slightly wonky with permissions. it should be obvious what needs to be chown'd or whatever though. after that a straight 'grunt' will compile all the things and concatenate and minify to dist/melchior.js and dist/melchior.min.js.

###example

Tick a clock

import Control.Category
import Melchior.Control
import Melchior.Dom
import Melchior.Dom.Selectors
import Melchior.Sink
import Melchior.Time

main :: IO ()
main = runDom setup

setup :: [Element] -> Dom ()
setup html = do
        output <- Dom $ select (byId "out" . from) html
        tick output

tick :: Maybe Element -> Dom ()
tick Nothing = return ()
tick (Just out) = put out elapsed

elapsed :: Signal Int
elapsed = foldp (\_ e -> e + 1) 0 $ every second

Echo user input in reverse

import Control.Applicative
import Control.Category
import Melchior.Control
import Melchior.Data.String
import Melchior.Dom
import Melchior.Dom.Selectors
import Melchior.Sink

main :: IO ()
main = runDom setup

setup :: [Element] -> Dom ()
setup html = do
  inp <- Dom $ select (inputs . byId "inp" . from) html
  out <- Dom $ select (byId "out" . from) html
  reversal inp out

reversal :: Maybe Input -> Maybe Element -> Dom ()
reversal i o = case f i o of
    Nothing -> return ()
    Just x -> x
    where f i o = do
        inp <- i
        out <- o
        Just $ put out $ (reverse . jsStringToString) <$> inputValue inp