v0.9.3

• Feature: Support PHP 8.1 release.
  (#208 by @clue)

• Fix: Fix automatic vertex ID generation when using vertex IDs with strings.
  (#204 by @viktorprogger)

• Improve test suite and use GitHub Actions for continuous integration (CI).
  (#207 by @clue)

v0.9.2

• Feature: Support PHP 8 and PHPUnit 9.3.
  (#200 by @SimonFrings)

v0.9.1

• Fix: Deleting vertex with loop edge no longer fails.
  (#149 by @tomzx)

• Fix: Fix returning directed loop edges and adjacent vertices from vertex twice.
  (#170 by @clue)

• Minor documentation updates and fixes.
  (#153 by @marclaporte and #163, #164 and #172 by @clue)

• Improve test suite to move tests to Fhaculty\Graph\Tests namespace,
  update test suite to support PHPUnit 6 and PHPUnit 5 and
  support running on legacy PHP 5.3 through PHP 7.2 and HHVM.
  (#148 by @tomzx and #150 and #162 by @clue)

• Originally planned to add a new AttributeAware::removeAttribute() method,
  but reverted due to BC break. Change will be reconsidered for next major release.
  (#138 and #171 by @johnathanmdell and @clue)

v0.9.0

• BC break: Split off individual components in order to stabilize core graph lib.
  (#120)
• Split off Algorithm namespace into separate graphp/algorithms package.
  (#119)
• Split off Exporter\TrivialGraphFormat into separate graphp/trivial-graph-format package.
  (#121)
• Split off Loader namespace into separate graphp/plaintext package.
  (#117)
• BC break: Remove Exporter from Graph and Graph::__toString() (trivial graph format exporter has been split off).
  (#122)
• BC break: Vertices can no longer be sorted by (in/out)degree (degree algorithm has been split off).
  (#128)
• Apply PSR-4 layout under src/ and add tests to achieve 100% test coverage.
  (#127 & #129)

v0.8.0

• Feature: Add general purpose Attributes.
  (#103)
• BC break: Split off all GraphViz-related classes to a separate
  graphp/graphviz package.
  (#115)
• Feature: The base Graph, Vertex and EdgeBase classes can now be
  extended in order to implement a custom behavior. As such, one can now also
  instantiate them using the normal new operator instead of having to use
  Graph::createVertex() family of methods.
  (#82)
• BC break: Rename Algorithm\Directed::isDirected() to remove its ambiguity
  in regards to mixed and/or empty graphs
  (#80)

Old name	New name
Algorithm\Directed::isDirected()	Algorithm\Directed::hasDirected()

• Feature: Add new Algorithm\Directed::hasUndirected() and
  Algorithm\Directed::isMixed() in order to complement the renamed
  Algorithm\Directed::hasDirected()
  (#80)
• BC break: Walk::factoryCycleFromVertices() no longer tries to auto-complete
  a cycle if the first vertex does not match the last one, but now throws an
  InvalidArgumentException instead (#87)
• Feature: Support loop Walks, i.e. a walk with only a single edge from
  vertex A back to A (#87)
• Fix: Stricter checks for invalid cycles, such as one with an invalid
  predecessor-map or no edges at all (#87)
• Fix: The Algorithm\ShortestPath\MooreBellmanFord now also works for unweighted
  edges. This also fixes an issue where Algorithm\DetectNegativeCycle didn't work
  for unweighted edges. (#81)
• Fix: The Algorithm\MinimumCostFlow algorithms now work again. The reference
  to a non-existant class has been updated. Also fixed several issues with
  regards to special cases such as disconnected or undirected graphs.
  (#74)
• BC break: Remove unneeded alias definitions of getVertexFirst(),
  getVertexSource() and getVertexTarget()
  (#76):

Old name	New name
Graph::getVertexFirst()	Graph::getVertices()->getVertexFirst()
Walk::getVertexSource()	Walk::getVertices()->getVertexFirst()
Walk::getVertexTarget()	Walk::getVertices()->getVertexLast()

v0.7.1

• Fix: Throwing an UnexpectedValueException if writing GraphViz Dot script
  to a temporary file fails and remove its debugging output
  (#77 and #78 @Metabor)
• Fix: Improved GraphViz support for MS Windows
  (#99)

v0.7.0

• Feature: Add new Set\Vertices and Set\Edges classes that handle common
  operations on a Set of multiple Vertex and Edge instances respectively.
  (#48)
• BC break: Move operations and their corresponding constants concerning Sets
  to their corresponding Sets:

Old name	New name
Edge\Base::getFirst()	Set\Edges::getEdgeOrder()
Edge\Base::getAll()	Set\Edges::getEdgesOrder()
Edge\Base::ORDER_*	Set\Edges::ORDER_*
---	---
Vertex::getFirst()	Set\Vertices::getVertexOrder()
Vertex::getAll()	Set\Vertices::getVerticesOrder()
Vertex::ORDER_	Set\Vertices::ORDER_*

• BC break: Each getVertices*() and getEdges*() method now returns a Set
  instead of a primitive array of instances. Most of the time this should
  work without changing your code, because each Set implements an Iterator
  interface and can easily be iterated using foreach. However, using a Set
  instead of a plain array differs when checking its boolean value or
  comparing two Sets. I.e. if you happen to want to check if an Set is empty,
  you now have to use the more explicit syntax $set->isEmpty().
• BC break: Vertex::getVertices(), Vertex::getVerticesEdgeTo() and
  Vertex::getVerticesEdgeFrom() now return a Set\Vertices instance that
  may contain duplicate vertices if parallel (multiple) edges exist. Previously
  there was no easy way to detect this situation - this is now the default. If
  you also want to get unique / distinct Vertex instances, use
  Vertex::getVertices()->getVerticesDistinct() where applicable.
• BC break: Remove all occurances of getVerticesId(), use
  getVertices()->getIds() instead.
• BC break: Merge Cycle into Walk (#61).
  As such, its static factory methods had to be renamed. Update your references if applicable:

Old name	New name
Cycle::factoryFromPredecessorMap()	Walk::factoryCycleFromPredecessorMap()
Cycle::factoryFromVertices()	Walk::factoryCycleFromVertices()
Cycle::factoryFromEdges()	Walk::factoryCycleFromEdges()

• BC break: Remove Graph::isEmpty() because it's not well-defined and might
  be confusing. Most literature suggests it should check for existing edges,
  whereas the old behavior was to check for existing vertices instead. Use either
  of the new and more transparent methods
  Algorithm\Property\GraphProperty::isNull() (old behavior) or (where applicable)
  Algorithm\Property\GraphProperty::isEdgeless() (#63).
• BC break: Each of the above methods (Walk::factoryCycleFromPredecessorMap(),
  Walk::factoryCycleFromVertices(), Walk::factoryCycleFromEdges()) now
  actually makes sure the returned Walk instance is actually a valid Cycle,
  i.e. the start Vertex is the same as the end Vertex (#61)
• BC break: Each Algorithm\ShortestPath algorithm now consistenly does not
  return a zero weight for the root Vertex and now supports loop edges on the root
  Vertex (#62)
• BC break: Each Algorithm\ShortestPath algorithm now consistently throws an
  OutOfBoundsException for unreachable vertices
  (#62)
• BC break: A null Graph (a Graph with no Vertices and thus no Edges) is not a
  valid tree (because it is not connected), adjust Algorithm\Tree\Base::isTree()
  accordingly.
  (#72)
• BC break: Remove all occurances of getNumberOfVertices() and
  getNumberOfEdges() (#75 and
  #48):

Old name	New name
$set->getNumberOfVertices()	count($set->getVertices())
$set->getNumberOfEdges()	count($set->getEdges())

• BC break: Replace base Set class with Set\DualAggregate interface. This
  is unlikely to affect you, but might potentially break your custom
  inheritance or polymorphism for algorithms.
  (#75)
• Feature: Add Algorithm\ShortestPath\Base::hasVertex(Vertex $vertex) to check whether
  a path to the given Vertex exists (#62).
• Feature: Support opening GraphViz images on Mac OS X in default image viewer
  (#67 @onigoetz)
• Feature: Add Algorithm\MinimumSpanningTree\Base::getWeight() to get total
  weight of resulting minimum spanning tree (MST).
  (#73)
• Feature: Each Algorithm\MinimumSpanningTree algorithm now supports
  undirected and mixed Graphs, as well as null weights for Edges.
  (#73)
• BC break: Each Algorithm\MinimumSpanningTree algorithm now throws an
  UnexpectedValueException for unconnected Graphs (and thus also null Graphs).
  (#73)
• Feature: Add Walk::factoryFromVertices()
  (#64).
• Fix: Checking Walk::isValid()
  (#61)
• Fix: Missing import prevented
  Algorithm\ShortestPath\MooreBellmanFord::getCycleNegative() from actually
  throwing the right UnderflowException if no cycle was found
  (#62)
• Fix: Calling Exporter\Image::setFormat() had no effect due to misassignment
  (#70 @fgm)

v0.6.0

• BC break: Move algorithm definitions in base classes to separate algorithm classes (#27).
  The following methods containing algorithms were now moved to separate algorithm classes. This
  change encourages code-reuse, simplifies spotting algorithms, helps reducing complexity,
  improves testablity and avoids tight coupling. Update your references if applicable:

Old name	New name	Related ticket
Set::getWeight()	Algorithm\Weight::getWeight()	#33
Set::getWeightFlow()	Algorithm\Weight::getWeightFlow()	#33
Set::getWeightMin()	Algorithm\Weight::getWeightMin()	#33
Set::isWeighted()	Algorithm\Weight::isWeighted()	#33
-	-	-
Graph::getDegree()	Algorithm\Degree::getDegree()	#29
Graph::getDegreeMin()	Algorithm\Degree::getDegreeMin()	#29
Graph::getDegreeMax()	Algorithm\Degree::getDegreeMax()	#29
Graph::isRegular()	Algorithm\Degree::isRegular()	#29
Graph::isBalanced()	Algorithm\Degree::isBalanced()	#29
Vertex::getDegree()	Algorithm\Degree:getDegreeVertex()	#49
Vertex::getDegreeIn()	Algorithm\Degree:getDegreeInVertex()	#49
Vertex::getDegreeOut()	Algorithm\Degree:getDegreeOutVertex()	#49
Vertex::isSink()	Algorithm\Degree:isVertexSink()	#49
Vertex::isSource()	Algorithm\Degree:isVertexSource()	#49
Vertex::isIsolated()	Algorithm\Degree::isVertexIsolated()	#49
-	-	-
Set::isDirected()	Algorithm\Directed::isDirected()	#34
-	-	-
Graph::isSymmetric()	Algorithm\Symmetric::isSymmetric()	#41
-	-	-
Graph::isComplete()	Algorithm\Complete::isComplete()	#43
-	-	-
Set::hasFlow()	Algorithm\Flow::hasFlow()	#47
Graph::getBalance()	Algorithm\Flow::getBalance()	#30, #47
Graph::isBalancedFlow()	Algorithm\Flow::isBalancedFlow()	#30, #47
Vertex::getFlow()	Algorithm\Flow::getFlowVertex()	#47
-	-	-
Vertex::isLeaf()	Algorithm\Tree\Undirected::isVertexLeaf()	#44
-	-	-
Set::hasLoop()	Algorithm\Loop::hasLoop()	#51
Vertex::hasLoop()	Algorithm\Loop::hasLoopVertex()	#51
-	-	-
Set::hasEdgeParallel()	Algorithm\Parallel::hasEdgeParallel()	#52
Edge\Base::hasEdgeParallel()	Algorithm\Parallel::hasEdgeParallelEdge()	#52
Edge\Base::getEdgesParallel()	Algorithm\Parallel::getEdgeParallelEdge()	#52
-	-	-
Graph::isEdgeless()	Algorithm\Property\GraphProperty::isEdgeless()	#54
Graph::isTrivial()	Algorithm\Property\GraphProperty::isTrivial()	#54
Walk::isCycle()	Algorithm\Property\WalkProperty::isCycle()	#54
Walk::isPath()	Algorithm\Property\WalkProperty::isPath()	#54
Walk::hasCycle()	Algorithm\Property\WalkProperty::hasCycle()	#54
Walk::isLoop()	Algorithm\Property\WalkProperty::isLoop()	#54
Walk::isDigon()	Algorithm\Property\WalkProperty::isDigon()	#54
Walk::isTriangle()	Algorithm\Property\WalkProperty::isTriangle()	#54
Walk::isSimple()	Algorithm\Property\WalkProperty::isSimple()	#54
Walk::isHamiltonian()	Algorithm\Property\WalkProperty::isHamiltonian()	#54
Walk::isEulerian()	Algorithm\Property\WalkProperty::isEulerian()	#54

• BC break: Remove unneeded algorithm alias definitions (#31, #50). The following alias definitions
  have been removed, their original/actual name has already existed before and continues to work
  unchanged. Update your references if applicable:

Old/removed alias definition	Actual name
Graph::isConnected()	Algorithm\ConnectedComponents::isSingle()
Graph::hasEulerianCycle()	Algorithm\Eulerian::hasCycle()
Graph::getNumberOfComponents()	Algorithm\ConnectedComponents::getNumberOfComponents()
Graph::getNumberOfGroups()	Algorithm\Groups::getNumberOfGroups()
Graph::isBipartit()	Algorithm\Bipartit::isBipartit()
Vertex::hasPathTo()	Algorithm\ShortestPath\BreadthFirst::hasVertex()
Vertex::hasPathFrom()	Algorithm\ShortestPath\BreadthFirst::hasVertex()
Vertex::getVerticesPathTo()	Algorithm\ShortestPath\BreadthFirst::getVertices()
Vertex::getVerticesPathFrom()	Algorithm\ShortestPath\BreadthFirst::getVertices()

• BC break: Graph::createVertices() now returns an array of vertices instead of the
  chainable Graph (#19)
• BC break: Move Loader\UmlClassDiagram to separate fhaculty/graph-uml
  repo (#38)
• BC break: Remove needless Algorithm\MinimumSpanningTree\PrimWithIf
  (use Algorithm\MinimumSpanningTree\Prim instead)
  (#45)
• BC break: Vertex::createEdgeTo() now returns an instance of type
  Edge\Undirected instead of Edge\UndirectedId
  (#46)
• BC break: Edge\Base::setCapacity() now consistently throws an RangeException
  instead of InvalidArgumentException if the current flow exceeds the new maximum
  capacity (#53)
• Feature: New Algorithm\Tree namespace with algorithms for undirected and directed,
  rooted trees (#44)
• Feature: According to be above list of moved algorithm methods, the following algorithm
  classes have been added (#27):
• New Algorithm\Weight (#33)
• New Algorithm\Degree (#29, #49)
• New Algorithm\Directed (#34)
• New Algorithm\Symmetric (#41)
• New Algorithm\Complete (#43)
• New Algorithm\Flow (#30, #47)
• New Algorithm\Tree (#44)
• New Algorithm\Loop (#51)
• New Algorithm\Parallel (#52)
• New Algorithm\Property (#54)
• Feature: Graph::createVertices() now also accepts an array of vertex IDs
  (#19)
• Feature: Add Algorithm\Property\WalkProperty::hasLoop() alias definition for
  completeness (#54)
• Feature: Add Algorithm\Property\WalkProperty::isCircuit() definition to distinguish
  circuits from cycles (#54)
• Fix: Checking hamiltonian cycles always returned false
  (#54)
• Fix: A Walk with no edges is no longer considered a valid cycle
  (#54)
• Fix: Various issues with Vertex/Edge layout attributes
  (#32)
• Fix: Getting multiple parallel edges for undirected edges
  (#52)

v0.5.0

• First tagged release (See issue #20 for more info on why it starts as v0.5.0)