Performance issue with flow

[sindikat]

Consider this code (same code on Share-Elm.com):

import Graphics.Element as E exposing (Element, show)
import Mouse
import Signal exposing ((<~))

table = List.repeat 100 "-"

view : (Int, Int) -> Element
view (x,y) = E.flow E.down <| E.show (x,y) :: List.map (E.show) table

main = view <~ Mouse.position

Run this in elm-lang.org/try and try to move the mouse around. The mouse positions are updated very slowly and CPU usage becomes high. At first I thought it had to do with CSS transform actions translateX and translateY (a different variant of the code creates lots of these for every div), but now I suspect it has to do with constantly rewriting the DOM with each mouse movement.

Can that be considered a bug that should be fixed for Graphics.Element? (By implementing virtual-dom-style diffing or something like that?) If not, what is the idiomatic way to create lots of elements using Graphics.Element.flow, some of which will be changed according to signals? To explain: suppose I have a 2D game with a game grid 10x10, where tiles and objects might change during the game. If I have a view function that constantly redraws the game grid using flow, I have massive performance problems. But I have no idea how to workaround this, because I have to have view <~ foldp update model signal (or some form of that) in my main.

[evancz]

Sorry no one has gotten to this yet! With Elm 0.17, the Graphics.* modules have moved to evancz/elm-graphics so it makes sense to retarget issues there. I hope this will also mean it'll be easier to find folks to help handling them!

[evancz]

Sorry no one has gotten to this yet! With Elm 0.17, the Graphics.* modules have moved to evancz/elm-graphics so it makes sense to retarget issues there. I hope this will also mean it'll be easier to find folks to help handling them!