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

src/RTEX/Engine.php

@@ -0,0 +1,89 @@
+<?php
+
+    namespace RTEX;
+
+    use LogLib\Log;
+    use RTEX\Abstracts\VariableTypes;
+    use RTEX\Classes\Utilities;
+    use RTEX\Exceptions\Core\UnsupportedVariableType;
+    use RTEX\Interfaces\InstructionInterface;
+    use RTEX\Objects\Environment;
+    use RTEX\Objects\Program;
+
+    class Engine
+    {
+        /**
+         * @var Program
+         */
+        private $Program;
+
+        /**
+         * @var Environment
+         */
+        private $Environment;
+
+        public function __construct(Program $program)
+        {
+            $this->Program = $program;
+            $this->Environment = new Environment();
+        }
+
+        /**
+         * Executes the program by running the main script of the program
+         *
+         * @return void
+         * @throws UnsupportedVariableType
+         */
+        public function run()
+        {
+            foreach($this->Program->getMain()->getInstructions() as $instruction)
+            {
+                $this->eval($instruction);
+            }
+        }
+
+        /**
+         * Evaluates the variable or instruction and returns the result
+         *
+         * @param $input
+         * @return mixed
+         * @throws UnsupportedVariableType
+         * @noinspection PhpMissingReturnTypeInspection
+         */
+        public function eval($input)
+        {
+            switch(Utilities::determineType($input))
+            {
+                case VariableTypes::Instruction:
+                    /** @var InstructionInterface $input */
+                    return $input->eval($this);
+
+                default:
+                    return $input;
+            }
+        }
+
+        /**
+         * @return Program
+         */
+        public function getProgram(): Program
+        {
+            return $this->Program;
+        }
+
+        /**
+         * @param Program $Program
+         */
+        public function setProgram(Program $Program): void
+        {
+            $this->Program = $Program;
+        }
+
+        /**
+         * @return Environment
+         */
+        public function getEnvironment(): Environment
+        {
+            return $this->Environment;
+        }
+    }