File ghc-graphs.spec of Package ghc-graphs
#
# spec file for package ghc-graphs
#
# Copyright (c) 2016 SUSE LINUX GmbH, Nuernberg, Germany.
#
# All modifications and additions to the file contributed by third parties
# remain the property of their copyright owners, unless otherwise agreed
# upon. The license for this file, and modifications and additions to the
# file, is the same license as for the pristine package itself (unless the
# license for the pristine package is not an Open Source License, in which
# case the license is the MIT License). An "Open Source License" is a
# license that conforms to the Open Source Definition (Version 1.9)
# published by the Open Source Initiative.
# Please submit bugfixes or comments via http://bugs.opensuse.org/
#
%global pkg_name graphs
Name: ghc-%{pkg_name}
Version: 0.7
Release: 0
Summary: A simple monadic graph library
License: BSD-3-Clause
Group: System/Libraries
Url: https://hackage.haskell.org/package/%{pkg_name}
Source0: https://hackage.haskell.org/package/%{pkg_name}-%{version}/%{pkg_name}-%{version}.tar.gz
BuildRequires: ghc-Cabal-devel
# Begin cabal-rpm deps:
BuildRequires: ghc-array-devel
BuildRequires: ghc-containers-devel
BuildRequires: ghc-rpm-macros
BuildRequires: ghc-transformers-compat-devel
BuildRequires: ghc-transformers-devel
BuildRequires: ghc-void-devel
BuildRoot: %{_tmppath}/%{name}-%{version}-build
# End cabal-rpm deps
%description
A "not-very-Haskelly" API for calculating traversals of graphs that may be too
large to fit into memory. The algorithms included are inspired by the visitor
concept of the
<http://www.boost.org/doc/libs/1_57_0/libs/graph/doc/visitor_concepts.html
Boost Graph Library>.
Here is a very simple example of how we might execute a depth-first-search.
In this case the visitor simply collects the edges and vertices in the order
that the corresponding functions get called. After the necessary imports,
> import Data.Array > import Data.Monoid > import Data.Graph.AdjacencyList >
import Data.Graph.Algorithm > import Data.Graph.Algorithm.DepthFirstSearch
create an adjacency list where the vertices are labeled with integers.
> graph :: Array Int [Int] > graph = array (0, 3) [(0, [1,2]), (1, [3]), (2,
[3]), (3, [])]
<<http://i.imgur.com/Pod1SH0.png>>
We need a data structure that instantiates `Monoid` to combine the results of
our visitor functions.
' data Orderings = Orderings   {  enterV :: [Int]
  , enterE :: [(Int, Int)]   , gray :: [(Int, Int)]   ,
exitV :: [Int]   , black :: [(Int, Int)]   } deriving
Show
instance Monoid Orderings where  mempty = Orderings [] [] [] [] []
 mappend (Orderings a1 a2 a3 a4 a5)(Orderings b1 b2 b3 b4 b5) =
  Orderings (a1 ++ b1) (a2 ++ b2) (a3 ++ b3) (a4 ++ b4) (a5 ++ b5) '
The `dfs` function's first argument is of type `GraphSearch` which is a visitor
containing the functions to be run at various times during the search.
The second argument is the starting vertex for the search.
' orderings :: GraphSearch (AdjacencyList Int) Orderings orderings =
GraphSearch   (v -> return $ mempty {enterV = [v]}
  (e -> return $ mempty {enterE = [e]}   (e -> return
$ mempty {gray = [e]}   (v -> return $ mempty {exitV =
[v]}   (e -> return $ mempty {black = [e]} '
Finally `runAdjacencylist` unwraps the function in the `Adjacencylist` newtype
and runs it on `graph`.
> dfsTest :: Orderings > dfsTest = runAdjacencyList (dfs orderings 0) graph
Running `dfsTest` in ghci will yield:
' Orderings {enterV = [0,2,3,1], enterE = [(0,2),(2,3),(0,1)], gray = [],
exitV = [3,2,1,0], black = [(1,3)]} '.
%package devel
Summary: Haskell %{pkg_name} library development files
Group: Development/Libraries/Other
Requires: %{name} = %{version}-%{release}
Requires: ghc-compiler = %{ghc_version}
Requires(post): ghc-compiler = %{ghc_version}
Requires(postun): ghc-compiler = %{ghc_version}
%description devel
This package provides the Haskell %{pkg_name} library development files.
%prep
%setup -q -n %{pkg_name}-%{version}
%build
%ghc_lib_build
%install
%ghc_lib_install
%post devel
%ghc_pkg_recache
%postun devel
%ghc_pkg_recache
%files -f %{name}.files
%defattr(-,root,root,-)
%doc LICENSE
%files devel -f %{name}-devel.files
%defattr(-,root,root,-)
%doc CHANGELOG.markdown README.markdown
%changelog
