Merge list items having more list and items

Question

I am working on a list that happens to have such items

[
  %{localtions: [], doctors: [%{name: "Junaid", hospital: "west"}, %{name: "Farooq", hospital: "test"}]},
  %{localtions: [%{name: "Dom", address: "test"}, %{name: "Domi", address: "west"}], doctors: []},
  %{localtions: [], doctors: []},
  %{localtions: [%{name: "Dominic", address: "test"}, %{name: "DomDom", address: "west"}], doctors: []}
]

I am trying to convert it into this only.

[locations: [%{name: "Domi", address: "test"}, %{name: "Dom", address: "test"}%{name: "Dominic", address: "test"},  %{name: "DomDom", address: "west"}], doctors: [%{name: "Junaid", hospital: "west"}, %{name: "Farooq", hospital: "test"}]]

any help would be great, thank you.

you missed a colon sign in result section: address: "test"}%{name: "Dominic", — S4eed3sm, Dec 31 '21 at 13:39

S4eed3sm · Accepted Answer · 2022-01-04T10:27:14.073

You can use this functions based on your need:

t = [
    %{
      localtions: [],
      doctors: [%{name: "Junaid", hospital: "west"}, %{name: "Farooq", hospital: "test"}]
    },
    %{
      localtions: [%{name: "Dom", address: "test"}, %{name: "Dom", address: "west"}],
      doctors: []
    },
    %{localtions: [], doctors: []},
    %{
      localtions: [%{name: "Dominic", address: "test"}, %{name: "DomDom", address: "west"}],
      doctors: []
    }
  ]

the function is defined as:

  def name_is_unique(l) do
    Enum.reduce(l, %{}, fn x, mp ->
      Map.merge(mp, x, fn _k, v1, v2 ->
        Enum.reduce(v1 ++ v2, %{}, fn x, acc -> Map.put(acc, x.name, x) end)
        |> Map.values()
      end)
    end)
  end

  def duplication_check(l) do # with duplication check
    Enum.reduce(l, %{}, fn x, mp ->
      Map.merge(mp, x, fn _k1, mpV1, mpV2 ->
        (mpV1 ++ mpV2) # [%{name: "Dom"}, %{name: "Dom"}]
        |> Enum.reduce(MapSet.new(), fn inerListMap, inerMapSet ->
          MapSet.put(inerMapSet, inerListMap) # %{name: "Dom"}
        end)
        |> MapSet.to_list()
      end)
    end)
  end

  def with_duplication(l) do
    Enum.reduce(l, %{}, fn x, mp ->
      Map.merge(mp, x, fn _k1, mpV1, mpV2 ->
        mpV1 ++ mpV2
      end)
    end)
  end

if your uniqueness is the name key then use name_is_unique or if you want full uniqueness over map items use duplication_check and don't care about duplication use with_duplication

name_is_unique(t)
%{
  doctors: [
    %{hospital: "test", name: "Farooq"},
    %{hospital: "west", name: "Junaid"}
  ],
  localtions: [
    %{address: "west", name: "Dom"},
    %{address: "west", name: "DomDom"},
    %{address: "test", name: "Dominic"}
  ]
}

duplication_check(t)
%{
  doctors: [
    %{hospital: "test", name: "Farooq"},
    %{hospital: "west", name: "Junaid"}
  ],
  localtions: [
    %{address: "test", name: "Dom"},
    %{address: "test", name: "Dominic"},
    %{address: "west", name: "Dom"},
    %{address: "west", name: "DomDom"}
  ]
}

with_duplication(t)
%{
  doctors: [
    %{hospital: "west", name: "Junaid"},
    %{hospital: "test", name: "Farooq"}
  ],
  localtions: [
    %{address: "test", name: "Dom"},
    %{address: "west", name: "Dom"},
    %{address: "test", name: "Dominic"},
    %{address: "west", name: "DomDom"}
  ]
}

name was a metaphor sorry, there can be some other values as well instead of name — Junaid Farooq, Dec 31 '21 at 11:52
Does %{address: "test", name: "Dom"} and %{address: "west", name: "Dom"} have difference ? — S4eed3sm, Dec 31 '21 at 13:12
I updated the data again sorry for the confusion, the data will not be the same but all will be unique. — Junaid Farooq, Dec 31 '21 at 13:15
Hello, is it possible that you can remove MapSet? as there not going to be any duplicates — Junaid Farooq, Jan 04 '22 at 09:58
goddamn this code is nasty, I would recommend to refactor to small recursive functions instead of those reduces. — Daniel, Jan 04 '22 at 10:32
But as I remember, It is recommended that we use functions such as fold and reduce instead of defining our return function. — S4eed3sm, Jan 04 '22 at 10:53

score 0 · Answer 2 · answered Jan 15 '22 at 12:01

Input:

input_list = [
  %{
    doctors: [
      %{hospital: "west", name: "Junaid"},
      %{hospital: "test", name: "Farooq"}
    ],
    localtions: []
  },
  %{
    doctors: [],
    localtions: [
      %{address: "test", name: "Dom"},
      %{address: "west", name: "Domi"}
    ]
  },
  %{doctors: [], localtions: []},
  %{
    doctors: [],
    localtions: [
      %{address: "test", name: "Dominic"},
      %{address: "west", name: "DomDom"}
    ]
  }
]

Module:

defmodule Items do
  def sanitize(input_list),
    do: Enum.reduce(input_list, [localtions: [], doctors: []], &update_items(&2, &1))

  defp update_items([localtions: localtions_list, doctors: doctors_list], %{
         localtions: new_localtions,
         doctors: new_doctors
       }),
       do: [localtions: localtions_list ++ new_localtions, doctors: doctors_list ++ new_doctors]
end

IEX session:

iex()> Items.sanitize(input_list)

Result:

[
  localtions: [
    %{address: "test", name: "Dom"},
    %{address: "west", name: "Domi"},
    %{address: "test", name: "Dominic"},
    %{address: "west", name: "DomDom"}
  ],
  doctors: [
    %{hospital: "west", name: "Junaid"},
    %{hospital: "test", name: "Farooq"}
  ]
]

Merge list items having more list and items

2 Answers2