Refactor lazy-loading (closes #2, closes #4)

src/Interfaces/WritableCollection.php

@@ -30,6 +30,17 @@ public function set($key, $value);
    */
   public function lazy($key, callable $initializer);
 
+  /**
+   * Removes a key from the collection and returns its value
+   * 
+   * @param  mixed  $key      The key
+   * @param  mixed  $default  (optional) A default value to return if the collection does not
+   *                          contain `$key`.  Prevents NoSuchValueException from being thrown.
+   * 
+   * @return mixed            The value associated with the key
+   */
+  public function take($key, $default = null);
+
   /**
    * Removes a key from the array
    * 

src/Traits/ReadableCollectionTrait.php

@@ -1,7 +1,6 @@
 <?php namespace BapCat\Collection\Traits;
 
 use BapCat\Collection\Exceptions\NoSuchKeyException;
-use BapCat\Collection\LazyInitializer;
 use BapCat\Collection\Interfaces\Collection;
 
 /**
@@ -43,14 +42,12 @@ public function get($key, $default = null) {
       }
     }
 
-    // Grab the value
     $value = $this->collection[$key];
 
-    // Is it a lazy-loaded value
-    if($value instanceof LazyInitializer) {
-      // Evaluate and cache the result
+    if(array_key_exists($key, $this->lazy)) {
       $value = $value($key);
       $this->collection[$key] = $value;
+      unset($this->lazy[$key]);
     }
 
     return $value;
@@ -68,7 +65,16 @@ public function first() {
       throw new NoSuchKeyException(null, 'Can\'t get first value from empty collection');
     }
 
-    return reset($this->collection);
+    $value = reset($this->collection);
+    $key = key($this->collection);
+
+    if(array_key_exists($key, $this->lazy)) {
+      $value = $value($key);
+      $this->collection[$key] = $value;
+      unset($this->lazy[$key]);
+    }
+
+    return $value;
   }
 
   /**
@@ -83,7 +89,16 @@ public function last() {
       throw new NoSuchKeyException(null, 'Can\'t get last value from empty collection');
     }
 
-    return end($this->collection);
+    $value = end($this->collection);
+    $key = key($this->collection);
+
+    if(array_key_exists($key, $this->lazy)) {
+      $value = $value($key);
+      $this->collection[$key] = $value;
+      unset($this->lazy[$key]);
+    }
+
+    return $value;
   }
 
   /**
@@ -93,6 +108,14 @@ public function last() {
    *                values contained in the collection.
    */
   public function all() {
+    if(!empty($this->lazy)) {
+      foreach($this->lazy as $key) {
+        $this->collection[$key] = $this->collection[$key]($key);
+      }
+
+      $this->lazy = [];
+    }
+
     return $this->collection;
   }
 
@@ -105,7 +128,7 @@ public function all() {
    *                           `function($key, $value)`
    */
   public function each(callable $callback) {
-    array_walk($this->collection, $callback);
+    array_walk($this->all(), $callback);
   }
 
   /**
@@ -114,7 +137,7 @@ public function each(callable $callback) {
    * @returns array An array of all keys contained in the collection
    */
   public function keys() {
-    return array_keys($this->collection);
+    return array_keys($this->all());
   }
 
   /**
@@ -123,7 +146,7 @@ public function keys() {
    * @returns array An array of all values contained in the collection
    */
   public function values() {
-    return array_values($this->collection);
+    return array_values($this->all());
   }
 
   /**
@@ -132,7 +155,7 @@ public function values() {
    * @returns int The size of the collection
    */
   public function size() {
-    return count($this->collection);
+    return count($this->all());
   }
 
   /**

src/Traits/WritableCollectionTrait.php

@@ -1,6 +1,6 @@
 <?php namespace BapCat\Collection\Traits;
 
-use BapCat\Collection\LazyInitializer;
+use BapCat\Collection\Exceptions\NoSuchKeyException;
 
 /**
  * A basic implementation of WritableCollectionInterface
@@ -11,6 +11,13 @@ trait WritableCollectionTrait {
    */
   protected $collection = [];
 
+  /**
+   * Holds all lazy-loaded keys
+   * 
+   * @var  array<mixed>
+   */
+  protected $lazy = [];
+
   /**
    * Constructs a new WritableCollectionTrait
    * 
@@ -50,7 +57,31 @@ public function set($key, $value) {
    *                                the desired value upon first request.
    */
   public function lazy($key, callable $initializer) {
-    $this->collection[$key] = new LazyInitializer($initializer);
+    $this->collection[$key] = $initializer;
+    $this->lazy[$key] = $key;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function take($key, $default = null) {
+    if(!array_key_exists($key, $this->collection)) {
+      if(func_num_args() < 2) {
+        throw new NoSuchKeyException($key);
+      } else {
+        return $default;
+      }
+    }
+
+    $value = $this->collection[$key];
+    $this->remove($key);
+
+    if(array_key_exists($key, $this->lazy)) {
+      $value = $value($key);
+      unset($this->lazy[$key]);
+    }
+
+    return $value;
   }
 
   /**

tests/WritableCollectionTraitTest.php

@@ -0,0 +1,77 @@
+<?php
+
+use BapCat\Collection\Exceptions\NoSuchKeyException;
+use BapCat\Collection\Traits\WritableCollectionTrait;
+
+class WritableCollectionTraitTest extends PHPUnit_Framework_TestCase {
+  private $trait;
+  private $collection;
+
+  public function setUp() {
+    $this->trait = $this
+      ->getMockBuilder(WritableCollectionTrait::class)
+      ->getMockForTrait()
+    ;
+
+    $class = new ReflectionClass($this->trait);
+    $this->collection = $class->getProperty('collection');
+    $this->collection->setAccessible(true);
+  }
+
+  public function testAdd() {
+    $this->trait->add('test');
+
+    $this->assertSame(['test'], $this->getCollection());
+
+    $this->trait->add('test2');
+
+    $this->assertSame(['test', 'test2'], $this->getCollection());
+  }
+
+  public function testSet() {
+    $this->trait->set('key1', 'val1');
+
+    $this->assertSame(['key1' => 'val1'], $this->getCollection());
+
+    $this->trait->set('key2', 'val2');
+
+    $this->assertSame(['key1' => 'val1', 'key2' => 'val2'], $this->getCollection());
+  }
+
+  public function testAddAndSet() {
+    $this->trait->add('test');
+    $this->trait->set('key1', 'val1');
+
+    $this->assertSame(['test', 'key1' => 'val1'], $this->getCollection());
+  }
+
+  public function testTake() {
+    $this->setCollection(['key1' => 'val1', 'key2' => 'val2']);
+
+    $this->assertSame(['key1' => 'val1', 'key2' => 'val2'], $this->getCollection());
+    $this->assertSame('val1', $this->trait->take('key1'));
+    $this->assertSame(['key2' => 'val2'], $this->getCollection());
+    $this->assertSame('already removed', $this->trait->take('key1', 'already removed'));
+
+    $this->setExpectedException(NoSuchKeyException::class);
+    $this->trait->take('non-existant key');
+  }
+
+  public function testRemove() {
+    $this->setCollection(['key1' => 'val1', 'key2' => 'val2']);
+
+    $this->assertSame(['key1' => 'val1', 'key2' => 'val2'], $this->getCollection());
+
+    $this->trait->remove('key1');
+
+    $this->assertSame(['key2' => 'val2'], $this->getCollection());
+  }
+
+  private function getCollection() {
+    return $this->collection->getValue($this->trait);
+  }
+
+  private function setCollection(array $collection) {
+    $this->collection->setValue($this->trait, $collection);
+  }
+}