Sum, average, min, max and toString added

CHANGELOG.md

@@ -78,3 +78,16 @@
 - sizeIsGreaterThan function added
 - sizeIsLessThan function added
 - sizeIsBetween function added
+
+##7.0.0
+- The functionality of sum, average, min, max and concatenate moved into collection. 
+- Sum collection function added
+- Average collection function added
+- Min collection function added
+- Max collection function added
+- ToArrray collection function added
+- **Breaking change: sum utility function removed**
+- **Breaking change: average utility function removed**
+- **Breaking change: min utility function removed**
+- **Breaking change: max utility function removed**
+- **Breaking change: concatenate utility function removed**

README.md

@@ -278,6 +278,16 @@ Collection::from([1, 3, 3, 2])
 toArray(append([1, 3, 3, 2], 1, 'key')); //[1, 3, 3, 2, 'key' => 1]
 ```
 
+#### average() : double
+Returns average of values in this collection.
+```php
+Collection::from([1, 2, 3, 2])->average(); //2.0
+Collection::from([])->average(); //0.0
+```
+```php
+average([1, 2, 3]); //2.0
+```
+
 #### combine(array|Traversable $collection, bool $strict = false) : Collection
 Combines the values of this collection as keys, with values of $collection as values.  The resulting collection has length equal to the size of smaller collection. If $strict is true, the size of both collections must be equal, otherwise ItemNotFound is thrown. When strict, the collection is realized immediately.
 ```php
@@ -802,6 +812,26 @@ Collection::from([1, 3, 3, 2])
 toArray(values(mapcat([1, 3, 3, 2], function ($value) {return [[$value]];}))); //[[1], [3], [3], [2]]
 ``` 
 
+#### max() : mixed
+Returns mthe maximal value in this collection.
+```php
+Collection::from([1, 2, 3, 2])->max(); //3
+Collection::from([])->max(); //null
+```
+```php
+max([1, 2, 3, 2]); //3
+```
+
+#### min() : mixed
+Returns mthe minimal value in this collection.
+```php
+Collection::from([1, 2, 3, 2])->min(); //1
+Collection::from([])->min(); //null
+```
+```php
+min([1, 2, 3, 2]); //1
+```
+
 #### only(array|Traversable $keys) : Collection
 Returns a lazy collection of items associated to any of the keys from $keys.
 ```php
@@ -1136,6 +1166,16 @@ Collection::from([1, 3, 3, 2])
 toArray(splitWith([1, 3, 3, 2], function ($value) {return $value < 3;})); //[[1], [1 => 3, 2 => 3, 3 => 2]]
 ```
 
+#### sum() : double
+Returns a sum of all values in this collection.
+```php
+Collection::from([1, 2, 3])->sum(); //6
+Collection::from([])->sum(); //0
+```
+```php
+sum([1, 2, 3]); //6
+```
+
 #### take(int $numberOfItems) : Collection
 A form of slice that returns first $numberOfItems items.
 ```php
@@ -1204,6 +1244,16 @@ Collection::from([1, 3, 3, 2])->toArray(); //[1, 3, 3, 2]
 toArray([1, 3, 3, 2]); //[1, 3, 3, 2]
 ```
 
+#### toString() : string
+Returns a string by concatenating this collection's values into a string.
+```php
+Collection::from([1, 'a', 3, null])->toString(); //'1a3'
+Collection::from([])->toString(); //''
+```
+```php
+toString([1, 'a', 3, null]); //'1a3'
+```
+
 #### zip(array|Traversable[] ...$collections) : Collection
 Returns a lazy collection of non-lazy collections of items from nth position from this collection and each passed collection. Stops when any of the collections don't have an item at the nth position.
 ```php
@@ -1251,36 +1301,3 @@ Returns value of $value decremented by one.
 ```php
 decrement(2) === 1; //true
 ```
-
-#### sum(... int $values)
-Returns the sum of all arguments.
-
-```php
-sum(1, 2, 3) === 6; //true
-```
-
-#### max(... int $values)
-Returns the maximal value of all arguments.
-
-```php
-max(1, 5, 3) === 5; //true
-```
-
-#### min(... int $values)
-Returns the minimal value of all arguments.
-
-```php
-min(1, 5, 3) === 1; //true
-```
-#### average(... int $values)
-Returns the average value of all arguments.
-
-```php
-average(1, 2, 3) === 2.0; //true
-```
-
-#### concatenate(... string $values)
-Returns a string of all the arguments concatenated together.
-```php
-concatenate('a', 'b', 'c') == 'abc'; //true 
-```

src/CollectionTrait.php

@@ -806,6 +806,56 @@ public function sizeIsBetween($fromSize, $toSize)
         return sizeIsBetween($this->getItems(), $fromSize, $toSize);
     }
 
+    /**
+     * Returns a sum of all values in this collection.
+     *
+     * @return double
+     */
+    public function sum()
+    {
+        return sum($this->getItems());
+    }
+
+    /**
+     * Returns average of values from this collection.
+     *
+     * @return double
+     */
+    public function average()
+    {
+        return average($this->getItems());
+    }
+
+    /**
+     * Returns maximal value from this collection.
+     *
+     * @return mixed
+     */
+    public function max()
+    {
+        return \DusanKasan\Knapsack\max($this->getItems());
+    }
+
+    /**
+     * Returns minimal value from this collection.
+     *
+     * @return mixed
+     */
+    public function min()
+    {
+        return \DusanKasan\Knapsack\min($this->getItems());
+    }
+
+    /**
+     * Returns a string by concatenating the collection values into a string.
+     *
+     * @return string
+     */
+    public function toString()
+    {
+        return toString($this->getItems());
+    }
+
     /**
      * @return array|\Traversable
      */

src/collection_functions.php

@@ -1516,3 +1516,96 @@ function sizeIsBetween($collection, $fromSize, $toSize)
 
     return $fromSize < $itemsTempCount && $itemsTempCount < $toSize;
 }
+
+/**
+ * Returns a sum of all values in the $collection.
+ *
+ * @param array|Traversable $collection
+ * @return float
+ */
+function sum($collection)
+{
+    $result = 0.0;
+
+    foreach ($collection as $value) {
+        $result += $value;
+    }
+
+    return $result;
+}
+
+/**
+ * Returns average of values from $collection.
+ *
+ * @param array|Traversable $collection
+ * @return float
+ */
+function average($collection)
+{
+    $sum = 0.0;
+    $count = 0;
+
+    foreach ($collection as $value) {
+        $sum += $value;
+        $count++;
+    }
+
+    return $count ? (float) $sum/$count : 0.0;
+}
+
+/**
+ * Returns maximal value from $collection.
+ *
+ * @param array|Traversable $collection
+ * @return mixed
+ */
+function max($collection)
+{
+    $result = null;
+
+    foreach ($collection as $value) {
+        $result = $value > $result ? $value : $result;
+    }
+
+    return $result;
+}
+
+/**
+ * Returns minimal value from $collection.
+ *
+ * @param array|Traversable $collection
+ * @return mixed
+ */
+function min($collection)
+{
+    $result = null;
+    $hasItem = false;
+
+    foreach ($collection as $value) {
+        if (!$hasItem) {
+            $hasItem = true;
+            $result = $value;
+        }
+
+        $result = $value < $result ? $value : $result;
+    }
+
+    return $result;
+}
+
+/**
+ * Returns a string by concatenating the $collection values into a string.
+ *
+ * @param array|Traversable $collection
+ * @return string
+ */
+function toString($collection)
+{
+    $result = '';
+
+    foreach ($collection as $value) {
+        $result .= (string) $value;
+    }
+
+    return $result;
+}

src/utility_functions.php

@@ -51,58 +51,3 @@ function decrement($value)
 {
     return $value - 1;
 }
-
-/**
- * Returns a sum of all arguments.
- *
- * @param int|float|double[] ...$values
- * @return number
- */
-function sum(...$values)
-{
-    return array_sum($values);
-}
-
-/**
- * Returns the highest value from all arguments.
- *
- * @param int|float|double[] ...$values
- * @return mixed
- */
-function max(...$values)
-{
-    return \max($values);
-}
-
-/**
- * Returns the lowest value from all arguments.
- *
- * @param int|float|double[] ...$values
- * @return mixed
- */
-function min(...$values)
-{
-    return \min($values);
-}
-
-/**
- * Returns the average of all arguments.
- *
- * @param int|float|double[] ...$values
- * @return float
- */
-function average(...$values)
-{
-    return sum(...$values) / count($values);
-}
-
-/**
- * Concatenates all arguments.
- *
- * @param string[] ...$values
- * @return mixed
- */
-function concatenate(...$values)
-{
-    return implode('', $values);
-}