5.8.3.0
-------

* Data.Graph.Inductive.NodeMap now has functions mkLookupNode,
  insMapLookupNode, memberNode, and lookupNode for detecting whether a
  graph already contains a node (issue #72, PR #77).

5.8.2.0
-------

* Data.Graph.Inductive.Graph now only requires Graph, not DynGraph
  (issue #100).

* Documented that some functions are partial (issue #98).

* Add `insert` function as synonym for `&` (issue #90).

5.8.1.1
-------

* Data.Graph.Inductive.Query.Dominators.{dom,iDom} could fail for some
  graphs (issue #109, regression in 5.8.1.0).

5.8.1.0
-------

* Data.Graph.Inductive.PatriciaTree.Gr and
  Data.Graph.Inductive.Tree.Gr now have Functor instances.

* 'Gr a' is now an instance of Functor.

5.8.0.0
-------

* Breaking change: MonadFail is no longer a superclass of GraphM.
  This is to support GHC 9.4.  This has no effect on the IO and ST
  instances of GraphM, but may affect users.

5.7.0.3
-------

* Bump QuickCheck dependency

5.7.0.2
-------

* Bump dependencies.

5.7.0.1
-------

* Accidentally released the wrong version.

5.7.0.0
-------

* Updating the GraphM class to be compatible with the MonadFail proposal and GHC's
  MonadFailDesugaring language extension which is enabled by default by GHC-8.6.1.

5.6.0.0
-------

* The previous version should have been a major version bump due to
  the API change.

5.5.4.0
-------

* Improved type safety of shortest-path functions (in
  `Data.Graph.Inductive.Query.SP`) thanks to Nathan Collins.

    - `getDistance`, `spLength` and `sp` now return `Maybe` values.

* Fixed building on GHC < 7.4; previously uncaught due to
  cabal-install doing the wrong thing on Travis-CI.


5.5.3.1
-------

* Hopefully clearer documentation for `&`, `Context` and the
  `ufold`-based functions.

* Thanks to David Feuer, the existing benchmark suite is now runnable
  with `cabal bench`.

* Some performance improvements for `PatriciaTree`, thanks to David
  Feuer.

5.5.3.0
-------

* Additional closure functions by Matthew Danish.

* `Bifunctor` instances for base >= 4.8.0.0.

* An `ST`-based `GraphM` instance.

* Addition of `order` and `size` functions for finding the number of
  nodes and edges respectively in a graph (the former is an alias for
  the existing `noNodes` function).

* The rules for faster implementations of `insNode` and `insEdge` for
  `PatriciaTree` should fire more often now.

5.5.2.3
-------

* Earlier fix for `NFData` wasn't quite complete/correct.

5.5.2.2
-------

* Ensure firing of specialised rules for `PatriciaTree`.

* Better way of only creating `NFData` instances when possible.

5.5.2.1
-------

* Only create `NFData` instances for GHC >= 7.4.1.

5.5.2.0
-------

* Documentation, clean-up and refactoring of various parts of the
  library.

    - As part of this, various types now have instances for classes
      like `Show`, `Eq`, `Ord`, `NFData`, etc. where applicable.

    - In particular, the various options for use with depth-first
      search and shortest path queries was documented by David
      Luposchainsky.

* Addition of a proper test-suite.  So far it covers the
  `Data.Graph.Inductive.Graph` module and all
  `Data.Graph.Inductive.Query.*` modules except for `Monad`.

    - The tests are also automatically run for every (set of) commits
      thanks to Travis-CI.

* Arbitrary instances for the two graph types are now available in the
  new `fgl-arbitrary` sub-package.

* Now depends solely on the `transformers` library rather than `mtl`.

* Potentially breaking changes:

    These changes are those where the behaviour was un-specified or
    didn't match the documentation.

    - `nodeRange` and `nodeRangeM` for the various graph data
      structures erroneously returned `(0,0)` for empty graphs (making
      them indistinguishable from graphs containing the single node
      `0`).  They now match the default implementation of throwing an
      error.

    - The behaviour of `delLEdge` when dealing with multiple edges was
      unspecified; it now deletes only a single edge and the new
      function `delAllLEdge` deletes all edges matching the one
      provided.

* Additional functions thanks to Sergiu Ivanov:

    - Creating sub-graphs by `Node`- and `Context`-filtering as well
      as induced by a set of `Node`s.

    - Graph condensation (i.e. graph of
      strongly-connected-components).

    - Various edge- and neighbor-based helper functions.

* The graph types now have `Generic` instances thanks to Piotr
  Mlodawski.

* The `OrdGr` wrapper by Trevor Cook allows performing `Ord`-based
  comparisons on graphs.

5.5.1.0
-------

* Support added for GHC 7.10 by Herbert Valerio Riedel.

* Additional DFS query functions added by Conrad Parker.

* Repository location changed to GitHub.

* Code cleanup:

    - Replaced usage of internal FiniteMap copy with Data.Map and
      Data.Set from the containers library.

    - Remove usage of data type contexts.

    - Use newtypes where applicable.

5.5.0.1
-------

* Fix up Eq instances for Tree and PatriciaTree so that they work with
  multiple edges.

5.5.0.0
-------

* Add proper Show, Read and Eq instances to Data.Graph.Inductive.Tree
  and Data.Graph.Inductive.PatriciaTree.

* Add pretty-printing functions to Data.Graph.Inductive.Graph.  These
  are based upon the old Show implementation for
  Data.Graph.Inductive.Tree.

* Now use PatriciaTree by default rather than Tree (and recommend as
  such).  IntMap has been receiving a lot of optimisation work on it,
  whereas the internal FiniteMap implementation hasn't received any
  attention.

* The `version :: IO ()` action now uses the actual Cabal version.

* Remove Data.Graph.Inductive.Graphviz; use the graphviz package
  instead.

5.4.2.4
-------

* Update to work with GHC-7.2 and Cabal-1.6.

5.4.2.3
-------

* Maintainership taken over by Ivan Miljenovic.

* Allow Data.Graph.Inductive.PatriciaTree to deal with multiple edges
  between nodes.

5.4.2.2 (November 2008)
-----------------------

* Bugfix in Graphviz.sq

5.4.2.1 (June 2008)
-------------------

* bug fix in bcc by Reid Barton

* added new dynamic graph implementation:
  Data.Graph.Inductive.PatriciaTree (thanks to Pho)

* added test/benchmark.hs: a benchmark to compare Tree and PatriciaTree
  implementations (thanks to Pho)

5.4.2 (May 2008)
----------------

* added Setup.hs to tar file

* reimplementation of Data.Graph.Inductive.Query.Dominators
  by Bertram Felgenhauer:

  It was buggy and very slow for large graphs. See
      http://www.haskell.org/pipermail/haskell-cafe/2008-April/041739.html

  This patch also adds a new function, iDom, that returns the
  immediate dominators of the graph nodes.

* Exported xdf*With functions from DFS.hs

* many little cleanups thanks to many people
  (use 'darcs changes' to see the details)

5.4 (April 2007)
----------------

* changed the implementation for inspection functions (suc, pred, ...)
  to correct the behavior in the presence of loops (thanks to Ralf
  Juengling for pointing out the inconsistency)

5.3 (June 2006)
---------------

* fixed a bug in findP (thanks to lnagy@fit.edu)

* added function delLEdge in Graph.hs (thanks to Jose Labra)

* changed implementation of updFM and mkGraph (thanks to Don Stewart)

February 2005
-------------

* fixed an import error in Basic.hs

* removed Eq instance of gr because it caused overlapping instance
  problems.  Instead the function equal defined in Graph.hs can be
  used

* added some more functions to the export list of DFS.hs

* changed the definition of LPath into a newtype to avoid overlapping
  instances with lists

* fixed the Makefile (for GHC and GHCi)


January 2004
------------

* bug fix for nearestNode (src/Data/Graph/Inductive/Query/GVD.hs)
  Update contributed by Aetion Technologies LLC (www.aetion.com)

* Refactor into hierarchical namespace

* Build changes:
  - build a standard haskell library (libHSfgl.a, HSfgl.o)
  - install as ghc package (fgl), uses Auto so no -package is needed

* Automatic Node generation for labels: Data.Graph.Inductive.NodeMap

* Graphviz output: Data.Graph.Inductive.Graphviz

September 2002
--------------

* Introduction of graph classes

* Monadic graphs and graph computation monad

* Graph implementation based on balanced (AVL) trees

* Fast graph implementation based on IO arrays

* New algorithms:
  - Maximum flow
  - Articulation points
  - biconnected components
  - dominators
  - transitive closure

* minor changes in utility functions
  - changed signatures (swapped order of arguments) of
    functions context and lab to be consistent with other graph functions
  - changed function first in RootPath: not existing path is now reported
    as an empty list and will not produce an error
  - esp version that returns a list of labeled edges
    (to find minimum label in maxflow algorithm)
  - BFS uses amortized O(1) queue
  - Heap stores key and value separately
  - ...

March 2001
----------
* Changes to User Guide

* a couple of new functions

* some internal changes

April 2000
----------

* User Guide

* Systematic structure for all depth-first search functions

* Graph Voronoi diagram

* Several small changes and additions in utility functions

February 2000
-------------

* Representation for inward-directed trees

* Breadth-first search

* Dijkstra's algorithm

* Minimum-spanning-tree algorithm


August 1999
-----------

* First Haskell version