Handle inequality comparisons with technical data.

lib/Alchemy/Phrasea/SearchEngine/Elastic/AST/KeyValue/FieldKey.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace Alchemy\Phrasea\SearchEngine\Elastic\AST\KeyValue;
+
+use Assert\Assertion;
+
+class FieldKey implements Key
+{
+    private $name;
+
+    public function __construct($name)
+    {
+        Assertion::string($name);
+        $this->name = $name;
+    }
+
+    public function getIndexField()
+    {
+        return 'yolo';
+    }
+
+    public function getValue()
+    {
+        return $this->name;
+    }
+
+    public function __toString()
+    {
+        return sprintf('field.%s', $this->name);
+    }
+}