sorting - 根据 map 中的值对 map 列表进行排序

Question

我有这个 list :

  [%Statcasters.PredictionScore{__meta__: #Ecto.Schema.Metadata<:loaded, "prediction_scores">,
  id: 1, inserted_at: ~N[2018-01-15 20:24:33.838946],
  league: #Ecto.Association.NotLoaded<association :league is not loaded>,
  league_id: 1, points: 4,
  prediction: #Ecto.Association.NotLoaded<association :prediction is not loaded>,
  prediction_id: 1,
  question: #Ecto.Association.NotLoaded<association :question is not loaded>,
  question_id: 1, updated_at: ~N[2018-01-15 20:24:33.838952]},
 %Statcasters.PredictionScore{__meta__: #Ecto.Schema.Metadata<:loaded, "prediction_scores">,
  id: 2, inserted_at: ~N[2018-01-15 20:24:33.842205],
  league: #Ecto.Association.NotLoaded<association :league is not loaded>,
  league_id: 1, points: 3,
  prediction: #Ecto.Association.NotLoaded<association :prediction is not loaded>,
  prediction_id: 2,
  question: #Ecto.Association.NotLoaded<association :question is not loaded>,
  question_id: 1, updated_at: ~N[2018-01-15 20:24:33.842210]}]

如您所见，每个 map 都有一个点键。我想对列表内的 map 进行排序，并返回最低点整数 map 作为列表的第一个元素。

当前尝试:

Enum.map(points, fn(p) -> p.points end) |> Enum.sort

这是行不通的，因为它仅返回排序的点。我需要整个 map 。

Answer 1

我相信Enum.sort_by/2是您想要的:

Enum.sort_by(points, fn(p) -> p.points end)

编辑:按多列排序，将它们放在元组/列表中:

Enum.sort_by(points, fn(p) -> {p.points, p.coordinate} end)