# libgraph
[](https://travis-ci.org/bitwalker/libgraph)
[](https://hex.pm/packages/libgraph)
[Documentation](https://hexdocs.pm/libgraph)
## About
This library provides an alternative directed graph implementation (i.e. replaces `:digraph`).
I created this library because one of my current projects has a need for doing processing on large
numbers of graphs concurrently. As `:digraph` requires a minimum of 3 ETS tables per graph, and up to 6
depending on what queries you are running on it, this means you can very easily hit the max ETS tables
system limit and crash a node. So, the need for a non-ETS backed graph structure became evident.
I'm not attempting to make an API that matches `:digraph`, though they will be similar for obvious reasons.
I'm likely also only going to implement the operations that I feel are common or that I need myself, but feel
free to open an issue if there is something missing that you would like to have, and I'll do my best to get
it implemented if I feel it belongs here.
If you are curious, there is a test suite, including QuickCheck-style tests, and some benchmarks which compare
some common scenarios with both `:digraph` and `libgraph`. So far, I've been able to get `libgraph` to outperform
`:digraph`, but the benchmarks are by no means comprehensive, so I would recommend doing some of your own which
reflect your use case. That said, *please* let me know if you find any pathological performance issues with this
library, as I would like to ensure that as much as possible, `libgraph` either matches the performance of `:digraph`,
or exceeds it.
## Installation
If [available in Hex](https://hex.pm/docs/publish), the package can be installed
by adding `libgraph` to your list of dependencies in `mix.exs`:
```elixir
def deps do
[{:libgraph, "~> 0.1"}]
end
```
## Roadmap
The following are items I plan to implement soon - they are not in any particular order.
- [x] Graph reducer, allowing you to manipulate the graph as you walk it
- [x] Graph iterators, allow you to walk a graph via BFS/DFS, applying a function as you go
- [x] Implement weighted edges, and a corresponding shortest path implementation
## License
MIT (See the LICENSE file)
