danj3 / list_merge

Elixir: merge list of lists using db type join

ListMerge

Merge a list of lexically sorted lists, using a protocol for returning an element key, with a each resulting cell containing a list of key-equal elements from the original lists.

In effect, this is a database type join operation on a list of lists.

Example (from test)

input = [
  [ 1,3,5,6,8 ],
  [ 5,8 ],
  [ 1,3,8 ]
]

ListMerge.merge( input )

Results in:

[
  [8, 8, 8],
  [6],
  [5,5],
  [3,3],
  [1,1]
]

The result is reversed from the input. Use Enum.reverse to return the ordering.

Installation

If available in Hex, the package can be installed by adding list_merge to your list of dependencies in mix.exs:

def deps do
  [
    {:list_merge, "~> 0.1.0"}
  ]
end

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/list_merge.