first commit

class/class.Range.php

@@ -0,0 +1,41 @@
+<?php
+
+class Range implements \JsonSerializable
+{
+    private $min;
+    private $max;
+
+    public function __construct($min = null, $max = null)
+    {
+        $this->min = $min;
+        $this->max = $max;
+    }
+
+    public function min()
+    {
+        return $this->min;
+    }
+
+    public function max()
+    {
+        return $this->max;
+    }
+
+    public function isNull()
+    {
+        return $this->min === null && $this->max === null;
+    }
+
+    public function isNotNull()
+    {
+        return !$this->isNull();
+    }
+
+    public function jsonSerialize(): mixed
+    {
+        return [
+            'min' => $this->min,
+            'max' => $this->max,
+        ];
+    }
+}