Added base files, with the basic ability to add/remove variables from the Runtime.

src/RTEX/Objects/Program/Instructions/GetVariable.php

@@ -0,0 +1,94 @@
+<?php
+
+    namespace RTEX\Objects\Program\Instructions;
+
+    use RTEX\Abstracts\InstructionType;
+    use RTEX\Classes\Utilities;
+    use RTEX\Engine;
+    use RTEX\Exceptions\Core\UnsupportedVariableType;
+    use RTEX\Interfaces\InstructionInterface;
+
+    class GetVariable implements InstructionInterface
+    {
+        /**
+         * The name of the variable to select
+         *
+         * @var string|integer|boolean|float|null|InstructionInterface|InstructionInterface[]
+         */
+        private $Variable;
+
+        /**
+         * Returns the type of instruction
+         *
+         * @return string
+         * @see InstructionType
+         */
+        public function getType(): string
+        {
+            return InstructionType::GetVariable;
+        }
+
+        /**
+         * Returns an array representation of the object
+         *
+         * @return array
+         * @throws UnsupportedVariableType
+         */
+        public function toArray(): array
+        {
+            return [
+                'type' => $this->getType(),
+                '_' => [
+                    'variable' => Utilities::toArray($this->Variable)
+                ]
+            ];
+        }
+
+        /**
+         * Returns
+         *
+         * @return bool|float|int|InstructionInterface|string|null
+         * @noinspection PhpMissingReturnTypeInspection
+         */
+        public function getVariable()
+        {
+            return $this->Variable;
+        }
+
+        /**
+         * @param bool|float|int|InstructionInterface|string|null $variable
+         * @throws UnsupportedVariableType
+         */
+        public function setVariable($variable): void
+        {
+            switch(Utilities::determineType($variable))
+            {
+
+
+                default:
+                    $this->Variable = $variable;
+            }
+        }
+
+        /**
+         * Constructs a new GetVariable instruction from an array representation
+         *
+         * @throws UnsupportedVariableType
+         */
+        public static function fromArray(array $data): InstructionInterface
+        {
+            $instruction = new GetVariable();
+            $instruction->setVariable($data['variable'] ?? null);
+            return $instruction;
+        }
+
+        /**
+         * @inheritDoc
+         */
+        public function eval(Engine $engine)
+        {
+            return $engine->getEnvironment()->getRuntimeVariable(
+                $engine->eval($this->Variable)
+            );
+        }
+    }