Add in Porter and Snowball Stemmer

Author: yooper

composer.json

@@ -26,7 +26,9 @@
     "require" : {
         "php": ">=5.5",
         "yooper/stop-words": "^1.0",
-        "symfony/console": ">=2.7"
+        "symfony/console": ">=2.7",
+        "camspiers/porter-stemmer": "1.0.0",
+        "wamania/php-stemmer": "1.1"
     },
     "require-dev": {
         "phpunit/phpunit": "5.*",

src/Stemmers/PorterStemmer.php

@@ -3,16 +3,33 @@
 namespace TextAnalysis\Stemmers;
 
 use TextAnalysis\Interfaces\IStemmer;
+use Porter;
+
 /**
- * Implementation of the PorterStemmer
+ * Wraps an existing library that provides the porter stemmer
  *
  * @author yooper
  */
 class PorterStemmer implements IStemmer
 {
-
+    /**
+     *
+     * @var Porter
+     */
+    protected $porterStemmer = null;
+    
+    public function __construct() 
+    {
+        $this->porterStemmer = new Porter();
+    }
+    
+    /**
+     * 
+     * @param string $token
+     * @return string
+     */
     public function stem($token) 
     {
-        die('not implemented');
+        return $this->porterStemmer->Stem($token);
     }
 }

src/Stemmers/SnowballStemmer.php

@@ -0,0 +1,35 @@
+<?php
+
+namespace TextAnalysis\Stemmers;
+
+use TextAnalysis\Interfaces\IStemmer;
+
+/**
+ * A wrapper around PHP native snowball implementation
+ * @author yooper
+ */
+class SnowballStemmer implements IStemmer
+{
+    const BASE_NAMESPACE = '\\Wamania\\Snowball\\';
+    
+    /**
+     *
+     * @var \Wamania\Snowball\Stem
+     */
+    protected $stemmer;
+    
+    public function __construct($stemmerType = 'English') 
+    {
+        $className = self::BASE_NAMESPACE.$stemmerType;
+        if(!class_exists($className)) { 
+            throw new \RuntimeException("Class {$stemmerType} does not exist");
+        }
+        $this->stemmer = new $className();
+    }
+    
+    public function stem($token) 
+    {
+        return $this->stemmer->stem($token);
+    }
+
+}

tests/TextAnalysis/Stemmers/PorterStemmerTest.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace Tests\TextAnalysis\Stemmers;
+
+use TextAnalysis\Stemmers\PorterStemmer;
+
+
+/**
+ * Description of PorterStemmerTest
+ *
+ * @author yooper
+ */
+class PorterStemmerTest extends \PHPUnit_Framework_TestCase
+{
+    public function testStemmer()
+    {
+        $stemmer = new PorterStemmer();
+        $this->assertEquals('univers', $stemmer->stem('universities'));
+        $this->assertEquals('judg',$stemmer->stem('judges'));
+    }
+}

tests/TextAnalysis/Stemmers/SnowballStemmerTest.php

@@ -12,34 +12,22 @@ class SnowballStemmerTest extends \PHPUnit_Framework_TestCase
 {
     public function testDefaultEnglish()
     {       
-        if( getenv('SKIP_TEST') || !extension_loaded('stem')) {
-            return;
-        }
-        $stemmer = new SnowballStemmer('english', $exceptions = ['universities' => 'university']);
+        $stemmer = new SnowballStemmer('English');
         $this->assertEquals("judg", $stemmer->stem("judges"));
         $this->assertEquals('ski', $stemmer->stem('skis'));
-        $this->assertEquals('university', $stemmer->stem('universities'));
-        $this->assertEquals('news', $stemmer->stem('news'));
-        
-        
-        
+        $this->assertEquals('univers', $stemmer->stem('universities'));
+        $this->assertEquals('news', $stemmer->stem('news'));                        
     }
 
     public function testSwedish()
     {       
-        if( getenv('SKIP_TEST') || !extension_loaded('stem')) {
-            return;
-        }
-        $stemmer = new SnowballStemmer('swedish');
+        $stemmer = new SnowballStemmer('Swedish');
         $this->assertEquals("affärschef", $stemmer->stem("affärscheferna"));
     }    
 
     public function testException()
-    {
-        if( getenv('SKIP_TEST') || !extension_loaded('stem')) {
-            return;
-        }      
+    {     
         $this->setExpectedException('Exception');
-        $stemmer = new SnowballStemmer('ewok');
+        $stemmer = new SnowballStemmer('Wookie');
     }
 }