Strand

A library for graphs. This library is mostly an Elixir port of the amazing Loom library for Clojure.

Installation

This library is available in Hex. To install, add strand to your list of dependencies in mix.exs:

def deps do
  [{:strand, "~> 0.6"}]
end

Use

iex(1)> require MapSet, as: Set
iex(2)> require Strand.Protocol.Graph, as: G
iex(3)> require Strand.Protocol.Digraph, as: DG
iex(4)> require Strand.Impl.Digraph, as: Digraph
iex(5)> require Strand.Alg, as: Alg
iex(6)> x = %{a: Set.new([]),
              b: Set.new([:a]),
              c: Set.new([:b]),
              d: Set.new([:b, :e]),
              e: Set.new([:a]),
              f: Set.new([:d, :e])}
iex(7)> G.nodes(x)
#MapSet<[:a, :b, :c, :d, :e, :f]>
iex(8)> G.edges(x)
#MapSet<[b: :a, c: :b, d: :b, d: :e, e: :a, f: :d, f: :e]>
iex(9)> G.out_degree(x, :d)
# 2
iex(10)> G.has_edge?(x, {:f, :e})
# true
iex(11)> G.out_edges(x, :f)
#MapSet<[f: :d, f: :e]>
iex(12)> G.successors(x, :f)
#MapSet<[:d, :e]>
iex(13)> G.has_node?(x, :e)
# true
iex(14)> Alg.sort_topo(x)
[:a, :b, :c, :e, :d, :f]
iex(15)> DG.predecessors(x, :b)
#MapSet<[:c, :d]>
iex(16)> DG.transpose(x)
# %{a: #MapSet<[:b, :e]>, b: #MapSet<[:c, :d]>, d: #MapSet<[:f]>,
#   e: #MapSet<[:d, :f]>}
iex(17)> DG.in_edges(x, :b)
#MapSet<[c: :b, d: :b]>
iex(18)> DG.in_degree(x, :b)
# 2
iex(19)> dg = Digraph.new(x)
# %Strand.Digraph{adj: %{b: #MapSet<[:a]>,
#                        c: #MapSet<[:b]>,
#                        d: #MapSet<[:b, :e]>,
#                        e: #MapSet<[:a]>,
#                        f: #MapSet<[:d, :e]>},
#                 in: %{a: #MapSet<[:b, :e]>,
#                       b: #MapSet<[:c, :d]>,
#                       d: #MapSet<[:f]>,
#                       e: #MapSet<[:d, :f]>},
#                 nodeset: #MapSet<[:a, :b, :c, :d, :e, :f]>}
iex(20)> dg |> DG.transpose
# %Strand.Digraph{adj: %{a: #MapSet<[:b, :e]>,
#                        b: #MapSet<[:c, :d]>,
#                        d: #MapSet<[:f]>,
#                        e: #MapSet<[:d, :f]>},
#                 in: %{b: #MapSet<[:a]>,
#                       c: #MapSet<[:b]>,
#                       d: #MapSet<[:b, :e]>,
#                       e: #MapSet<[:a]>,
#                       f: #MapSet<[:d, :e]>},
#                 nodeset: #MapSet<[:a, :b, :c, :d, :e, :f]>}
iex(21)> dg |> DG.in_degree(:b)
# 2
iex(22)> dg |> DG.in_edges(:b)
#MapSet<[c: :b, d: :b]>
iex(23)> dg |> DG.predecessors(:b)
#MapSet<[:c, :d]>

License

Copyright (C) 2017 Clark Kampfe

Distributed under the Eclipse Public License.