Download directory and run:

cabal build 

Run:

cabal run

You’ll have to type the name of the file.

If you want to save the graph you enter to a file, you will have to type it manually, because gloss doesn’t allow to return the world state after the play function has started.

The format for the graph files is:

<v>| <vertices adjacent to v>
<u>| <vertices adjacent to u>
<w>| <vertices adjacent to w>

Example of the table of a 3 complete graph:

1| 23
2| 13
3| 12

If you don’t mind not saving the graph, you will be able to create it by clicking where you want the vertices to be and then clicking the pairs of vertices that should be adjacent.