libghc-topograph-dev binary package in Ubuntu Lunar armhf

 Directed acyclic graphs can be sorted topographically.
 Existence of topographic ordering allows writing many graph
 algorithms efficiently. Many graphs, including most
 dependency graphs, are acyclic.
 .
 There are some algorithms built in: dfs, transpose, transitive
 closure, transitive reduction, etc.
 .
 This package provides a library for the Haskell programming language.
 See http://www.haskell.org/ for more information on Haskell.

Source package