Merge pull request #80 from clue/directed

Rename Algorithm\Directed::isDirected()
graphp · Nov 26, 2013 · 52fc5d8 · 52fc5d8
2 parents 2769dc6 + bd92553
commit 52fc5d8
Show file tree

Hide file tree

Showing 6 changed files with 66 additions and 10 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -6,6 +6,19 @@ you spot any mistakes.
 
 ## 0.8.0 (2013-xx-xx)
 
+*   BC break: Rename `Algorithm\Directed::isDirected()` to remove its ambiguity
+    in regards to mixed and/or empty graphs
+    ([#80](https://github.com/clue/graph/issues/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](https://github.com/clue/graph/issues/80))
+
 *   Fix: Throwing an `UnexpectedValueException` if writing GraphViz Dot script
     to a temporary file fails and remove its debugging output
     ([#77](https://github.com/clue/graph/issues/77) and [#78](https://github.com/clue/graph/issues/78) @Metabor)

diff --git a/lib/Fhaculty/Graph/Algorithm/Directed.php b/lib/Fhaculty/Graph/Algorithm/Directed.php
@@ -4,6 +4,7 @@
 
 use Fhaculty\Graph\Algorithm\BaseGraph;
 use Fhaculty\Graph\Edge\Directed as EdgeDirected;
+use Fhaculty\Graph\Edge\Undirected as EdgeUndirected;
 
 /**
  * Basic algorithms for working with the undirected or directed Graphs (digraphs) / Walks.
@@ -14,11 +15,14 @@
 class Directed extends BaseDual
 {
     /**
-     * checks whether the graph has any directed edges (aka digraph)
+     * checks whether the graph has any directed edges
+     *
+     * This method is intentionally not named "isDirected()" (aka digraph),
+     * because that might be misleading in regards to empty and/or mixed graphs.
      *
      * @return boolean
      */
-    public function isDirected()
+    public function hasDirected()
     {
         foreach ($this->set->getEdges() as $edge) {
             if ($edge instanceof EdgeDirected) {
@@ -28,4 +32,35 @@ public function isDirected()
 
         return false;
     }
+
+    /**
+     * checks whether the graph has any undirected edges
+     *
+     * This method is intentionally not named "isUndirected()",
+     * because that might be misleading in regards to empty and/or mixed graphs.
+     *
+     * @return boolean
+     */
+    public function hasUndirected()
+    {
+        foreach ($this->set->getEdges() as $edge) {
+            if ($edge instanceof EdgeUndirected) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * checks whether this is a mixed graph (contains both directed and undirected edges)
+     *
+     * @return boolean
+     * @uses self::hasDirected()
+     * @uses self::hasUndirected()
+     */
+    public function isMixed()
+    {
+        return ($this->hasDirected() && $this->hasUndirected());
+    }
 }
diff --git a/lib/Fhaculty/Graph/Algorithm/MaximumMatching/Flow.php b/lib/Fhaculty/Graph/Algorithm/MaximumMatching/Flow.php
@@ -18,7 +18,7 @@ class Flow extends Base
     public function getEdges()
     {
         $alg = new Directed($this->graph);
-        if ($alg->isDirected()) {
+        if ($alg->hasDirected()) {
             throw new UnexpectedValueException('Input graph contains directed edges');
         }
 

diff --git a/lib/Fhaculty/Graph/GraphViz.php b/lib/Fhaculty/Graph/GraphViz.php
@@ -273,14 +273,14 @@ public function createImageFile()
      * create graphviz script representing this graph
      *
      * @return string
-     * @uses Directed::isDirected()
+     * @uses Directed::hasDirected()
      * @uses Graph::getVertices()
      * @uses Graph::getEdges()
      */
     public function createScript()
     {
         $alg = new Directed($this->graph);
-        $directed = $alg->isDirected();
+        $directed = $alg->hasDirected();
 
         $script = ($directed ? 'di':'') . 'graph G {' . self::EOL;
 

diff --git a/tests/Fhaculty/Graph/Algorithm/DirectedTest.php b/tests/Fhaculty/Graph/Algorithm/DirectedTest.php
@@ -11,7 +11,9 @@ public function testGraphEmpty()
 
         $alg = new AlgorithmDirected($graph);
 
-        $this->assertFalse($alg->isDirected());
+        $this->assertFalse($alg->hasDirected());
+        $this->assertFalse($alg->hasUndirected());
+        $this->assertFalse($alg->isMixed());
     }
 
     public function testGraphUndirected()
@@ -22,7 +24,9 @@ public function testGraphUndirected()
 
         $alg = new AlgorithmDirected($graph);
 
-        $this->assertFalse($alg->isDirected());
+        $this->assertFalse($alg->hasDirected());
+        $this->assertTrue($alg->hasUndirected());
+        $this->assertFalse($alg->isMixed());
     }
 
     public function testGraphDirected()
@@ -33,7 +37,9 @@ public function testGraphDirected()
 
         $alg = new AlgorithmDirected($graph);
 
-        $this->assertTrue($alg->isDirected());
+        $this->assertTrue($alg->hasDirected());
+        $this->assertFalse($alg->hasUndirected());
+        $this->assertFalse($alg->isMixed());
     }
 
     public function testGraphMixed()
@@ -45,6 +51,8 @@ public function testGraphMixed()
 
         $alg = new AlgorithmDirected($graph);
 
-        $this->assertTrue($alg->isDirected());
+        $this->assertTrue($alg->hasDirected());
+        $this->assertTrue($alg->hasUndirected());
+        $this->assertTrue($alg->isMixed());
     }
 }
diff --git a/tests/Fhaculty/Graph/Loader/CompleteGraphTest.php b/tests/Fhaculty/Graph/Loader/CompleteGraphTest.php
@@ -44,7 +44,7 @@ public function testDirected()
         $this->assertEquals($n*($n-1), count($graph->getEdges())); // n*(n-1) for directed graphs
 
         $alg = new Directed($graph);
-        $this->assertTrue($alg->isDirected());
+        $this->assertTrue($alg->hasDirected());
 
         $alg = new Complete($graph);
         $this->assertTrue($alg->isComplete());