Map Sorter

Sorts a list of maps per a list of sort specs.

Also supports:

• keywords
• structs implementing the Access behaviour
• nested maps, keywords or structs implementing the Access behaviour

Installation

Add map_sorter to your list of dependencies in mix.exs:

def deps() do
  [
    {:map_sorter, "~> 0.2"}
  ]
end

Usage

require MapSorter
MapSorter.sort(maps, sort_specs)

Examples of sort specs for flat data structures:

- implicit: [:dob, :name]
- mixed:    [:dob, desc: :name]
- explicit: [asc: :dob, desc: :name]

Examples of sort specs with a Date key for flat data structures:

- implicit: [{:dob, Date}, :name]
- mixed:    [{:dob, Date}, desc: :name]
- explicit: [asc: {:dob, Date}, desc: :name]

Examples of sort specs for nested data structures:

- implicit: [[:birth, :date], :name]
- mixed:    [[:birth, :date], desc: :name]
- explicit: [asc: [:birth, :date], desc: :name]

Examples of sort specs with a Date key for nested data structures:

- implicit: [{[:birth, :date], Date}, :name]
- mixed:    [{[:birth, :date], Date}, desc: :name]
- explicit: [asc: {[:birth, :date], Date}, desc: :name]

Example 1

require MapSorter

people = [
  %{name: "Mike", likes: "ski, arts", dob: "1992-04-15"},
  %{name: "Mary", likes: "travels"  , dob: "1992-04-15"},
  %{name: "Bill", likes: "karate"   , dob: "1977-08-28"},
  %{name: "Joe" , likes: "boxing"   , dob: "1977-08-28"},
  %{name: "Jill", likes: "cooking"  , dob: "1976-09-28"}
]

MapSorter.sort(people, asc: :dob, desc: :likes)

The above code will sort people ascendingly by :dob and descendingly by :likes as follows:

[
  %{name: "Jill", likes: "cooking"  , dob: "1976-09-28"},
  %{name: "Bill", likes: "karate"   , dob: "1977-08-28"},
  %{name: "Joe" , likes: "boxing"   , dob: "1977-08-28"},
  %{name: "Mary", likes: "travels"  , dob: "1992-04-15"},
  %{name: "Mike", likes: "ski, arts", dob: "1992-04-15"}
]

Example 2

require MapSorter

people = [
  %{name: "Mike", likes: "ski, arts", dob: ~D[1992-04-15]},
  %{name: "Mary", likes: "travels"  , dob: ~D[1992-04-15]},
  %{name: "Bill", likes: "karate"   , dob: ~D[1977-08-28]},
  %{name: "Joe" , likes: "boxing"   , dob: ~D[1977-08-28]},
  %{name: "Jill", likes: "cooking"  , dob: ~D[1976-09-28]}
]

MapSorter.sort(people, asc: {:dob, Date}, desc: :likes)

The above code will sort people ascendingly by :dob and descendingly by :likes as follows:

[
  %{name: "Jill", likes: "cooking"  , dob: ~D[1976-09-28]},
  %{name: "Bill", likes: "karate"   , dob: ~D[1977-08-28]},
  %{name: "Joe" , likes: "boxing"   , dob: ~D[1977-08-28]},
  %{name: "Mary", likes: "travels"  , dob: ~D[1992-04-15]},
  %{name: "Mike", likes: "ski, arts", dob: ~D[1992-04-15]}
]

Example 3

require MapSorter

people = [
  %{name: [first: "Meg", last: "Hill"], birth: [date: ~D[1977-01-23]]},
  %{name: [first: "Meg", last: "Howe"], birth: [date: ~N[1977-01-23 01:02:03]]},
  %{name: [first: "Joe", last: "Holt"], birth: [date: ~N[1988-01-23 23:59:59]]},
  %{name: [first: "Meg", last: "Hunt"], birth: [date: ~D[1988-01-23]]}
]

MapSorter.sort(people, desc: {[:birth, :date], Date}, asc: [:name, :last])

The above code will sort people descendingly by birth date and ascendingly by last name as follows:

[
  %{name: [first: "Joe", last: "Holt"], birth: [date: ~N[1988-01-23 23:59:59]]},
  %{name: [first: "Meg", last: "Hunt"], birth: [date: ~D[1988-01-23]]},
  %{name: [first: "Meg", last: "Hill"], birth: [date: ~D[1977-01-23]]},
  %{name: [first: "Meg", last: "Howe"], birth: [date: ~N[1977-01-23 01:02:03]]}
]