Ability to pluralise and singularise words

Author: DivineOmega

composer.json

@@ -6,7 +6,8 @@
         "php": "^7.0",
         "rapidwebltd/rw-file-cache": "^1.2",
         "divineomega/is_offensive": "^1.0",
-        "davechild/textstatistics": "^1.0"
+        "davechild/textstatistics": "^1.0",
+        "doctrine/inflector": "^1.2"
     },
     "require-dev": {
         "phpunit/phpunit": "^5.7",

src/Pluralizer.php

@@ -0,0 +1,61 @@
+<?php
+namespace DivineOmega\WordInfo;
+
+use Doctrine\Common\Inflector\Inflector;
+
+class Pluralizer
+{
+    private $irregular = [
+        'goose' => 'geese',
+    ];
+
+    private $uncountable = [
+        'audio',
+        'education',
+        'love',
+        'pokemon',
+        'mathematics'
+    ];
+
+    private $word;
+
+    public function __construct(string $word)
+    {
+        $this->word = $word;
+    }
+
+    public function pluralize()
+    {
+        if ($this->isUncountable()) {
+            return $this->word;
+        }
+
+        foreach($this->irregular as $singular => $plural) {
+            if ($singular==$this->word) {
+                return $plural;
+            }
+        }
+
+        return Inflector::pluralize($this->word);
+    }
+
+    public function singularize()
+    {
+        if ($this->isUncountable()) {
+            return $this->word;
+        }
+
+        foreach($this->irregular as $singular => $plural) {
+            if ($plural==$this->word) {
+                return $singular;
+            }
+        }        
+
+        return Inflector::singularize($this->word);
+    }
+
+    private function isUncountable()
+    {
+        return (in_array($this->word, $this->uncountable));
+    }
+}

src/Word.php

@@ -75,6 +75,16 @@ public function syllables()
         return Syllables::syllableCount($this->word);
     }
 
+    public function plural()
+    {
+        return (new Pluralizer($this->word))->pluralize();
+    }
+
+    public function singular()
+    {
+        return (new Pluralizer($this->word))->singularize();
+    }
+
     public function offensive()
     {
         return is_offensive($this->word);

tests/Unit/WordTest.php

@@ -123,4 +123,49 @@ public function testPortmanteaus2()
         $this->assertEquals($expected, $portmanteaus);
     }
 
+    private function getSingularToPluralData()
+    {
+        return [
+            'cat' => 'cats',
+            'mitten' => 'mittens',
+            'sausage' => 'sausages',
+            'child' => 'children',
+            'goose' => 'geese',
+            'person' => 'people',
+            'woman' => 'women',
+            'man' => 'men',
+            'audio' => 'audio',
+            'education' => 'education',
+            'rice' => 'rice',
+            'love' => 'love',
+            'pokemon' => 'pokemon',
+            'sheep' => 'sheep',
+            'sex' => 'sexes',
+            'mouse' => 'mice',
+            'mathematics' => 'mathematics',
+            'information' => 'information',
+            'tooth' => 'teeth'
+        ];
+    }
+
+    public function testPluralise()
+    {
+        $data = $this->getSingularToPluralData();
+
+        foreach($data as $singular => $plural) {
+            $word = new Word($singular);
+            $this->assertEquals($plural, $word->plural());
+        }
+    }
+
+    public function testSingularise()
+    {
+        $data = $this->getSingularToPluralData();
+
+        foreach($data as $singular => $plural) {
+            $word = new Word($plural);
+            $this->assertEquals($singular, $word->singular());
+        }
+    }
+
 }