added Alias type

Author: transistive

src/Alias.php

@@ -0,0 +1,59 @@
+<?php
+
+namespace WikibaseSolutions\CypherDSL;
+
+use WikibaseSolutions\CypherDSL\Types\AnyType;
+use function sprintf;
+
+class Alias implements AnyType
+{
+    /**
+     * @var Variable The original variable to be aliased
+     */
+    private Variable $original;
+
+    /**
+     * @var Variable The new variable aliasing the original
+     */
+    private Variable $variable;
+
+    /**
+     * BinaryOperator constructor.
+     *
+     * @param Variable $original The original variable to be aliased
+     * @param Variable $variable The new variable aliasing the original
+     */
+    public function __construct(Variable $original, Variable $variable)
+    {
+        $this->original = $original;
+        $this->variable = $variable;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function toQuery(): string
+    {
+        return sprintf("%s AS %s", $this->original->toQuery(), $this->variable->toQuery());
+    }
+
+    /**
+     * Gets the original variable of the alias.
+     *
+     * @return Variable
+     */
+    public function getOriginal(): Variable
+    {
+        return $this->original;
+    }
+
+    /**
+     * Gets the variable from the alias.
+     *
+     * @return Variable
+     */
+    public function getVariable(): Variable
+    {
+        return $this->variable;
+    }
+}