Playing around with custom sorting on nested structures in Elm.

sort_fun.elm

import Graphics.Element exposing (show)

type State = Ready | Working | Complete
  
stateSort a =
  case a.state of
    Ready -> 1
    Working -> 2
    Complete -> 3
  
type alias Row = 
  { pos : Int
  , state : State
  }
type alias Col =
  { rows : List Row
  , state : State
  }

model =
  {
  cols = 
    [ { state = Ready, rows = [] },
      { state = Working, rows = [] },
      { state = Complete, rows = [] }],    
  rows =
    [ { pos = 2, state = Ready}
    , { pos = 7, state = Working}
    , { pos = 3, state = Ready }
    , { pos = 5, state = Complete }
    , { pos = 6, state = Ready }
    , { pos = 4, state = Working }]}

partitionRows x  =
  List.map (\col -> 
    { state = col.state, 
       rows = (List.sortBy .pos (List.filter (\r -> r.state == col.state) x.rows)) }) x.cols
  
showPartitionedRows = partitionRows model
  |> show 
  
showSortedRows = rows
  |> List.sortBy .pos
  |> List.sortBy stateSort
  |> show

main = showPartitionedRows