https://github.com/Cicayda/yolk-examples/blob/master/src/yolk_examples/client/autocomplete.cljs in Elm

gistfile1.elm

-- [x] Get input from user
-- [x] Do it only every two seconds
-- [x] Filter output < 3
-- [x] Send request to server
-- [x] Display results to user

import Graphics.Input as Input
import Maybe
import Http as H
import Json as J
import Time as T
-- Syntax
add : Int -> Int -> Int
add x y = y |> (+) x 
            |> (*) 2
            
divise : Float -> Float -> Maybe Float
divise x y = if y == 0 then Nothing else Just (x/y)


unsafeDivide : Float -> Float -> String
unsafeDivide x y = divise x y |> Maybe.maybe "Error" show 
-- util
keepMaybe : (a -> Bool) -> Signal a -> Signal (Maybe a)
keepMaybe pred =
     lift (\x -> if pred x then Just x else Nothing)

extractJsonString : J.JsonValue -> Maybe String
extractJsonString v =
  case v of
    J.String s -> Just s
    _          -> Nothing

-- signals
(field, rawSearchTerm) = Input.field "Input your search text"

searchResult = 
  rawSearchTerm |> keepMaybe validTerm               -- Signal Maybe String * filtered
                |> sampleOn (every (2 * T.second))   -- Signal Maybe String * once in 2 secs
                |> dropRepeats                       -- Signal Maybe String * without duplications
                |> lift (Maybe.maybe "" searchUrl)   -- Signal String       * converted to URL
                |> H.sendGet                         -- Signal Response String * response
                |> lift extractSuggestions           -- Signal [String]     * results extracted

-- behaviour 
searchUrl term = 
  "http://localhost:8080/wiki/w/api.php?format=json&action=opensearch&search=" ++ term 

extractSuggestions : H.Response String -> [String]
extractSuggestions res = case res of
  H.Success s -> s |> J.fromString |> \x -> justs [x] |> concatMap extractSuggestionsRaw 
  _           -> []
  
  
extractSuggestionsRaw : J.JsonValue -> [String]
extractSuggestionsRaw v = case v of
  J.Array [_, J.Array arr] -> arr |> map extractJsonString |> justs
  _                        -> []

validTerm term = length term > 2

-- view
main = lift2 above field 
                   (lift displayList searchResult)
                   
                   
displayList : [String] -> Element
displayList results = 
  results |> map (text . monospace . toText) -- [Element]
          |> flow down                       -- Element