Changelog for fgl-5.7.0.0
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
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* 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
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* Earlier fix for `NFData` wasn't quite complete/correct.
5.5.2.2
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* Ensure firing of specialised rules for `PatriciaTree`.
* Better way of only creating `NFData` instances when possible.
5.5.2.1
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* Only create `NFData` instances for GHC >= 7.4.1.
5.5.2.0
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* 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
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* 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