Add some preparation for sub program execution

src/Automata/Machine.php

@@ -9,6 +9,14 @@ use Program\Word;
 use RuntimeException;
 use SplStack;
 
+/*
+ * executing a program:
+ * - load parts program
+ * - execute line by line
+ * - load sub program
+ * - execute lines from subprogram
+ * - back to parts program
+ */
 class Machine
 {
 	public State $state;
@@ -47,19 +55,23 @@ class Machine
 			throw new RuntimeException('No program loaded');
 		}
 		foreach ($this->activeProgram as $block) {
-			// Do we apply a block or a word?
-			// Answer: depends! Some commands need
-			// more information from other words.
-			// TODO: Interpret commands such as preparation of a work cycle
-
-			$words = array_map(fn(Word $w) => $w->toString(), $block->words);
-			$words = implode("\t", $words);
-			$words = "N{$block->N}\t$words";
-
-			foreach ($block->words as $word) {
+			/** @var Word[] $words */
+			$words = $block->words;
+			while ($word = array_shift($words)) {
+				if ('G22' === $word->toString()) {
+					$identifier = array_shift($words);
+					if ($identifier->register !== 'X') {
+						throw new RuntimeException('Expected X9xxx after G22');
+					}
+					$subProgram = $this->subProgramMemory->read($identifier->value);
+					$this->programStack->push($subProgram);
+					system('clear');
+					dump($subProgram);
+					readline();
+					continue;
+				}
 				$this->state->apply($word);
 				system('clear');
-				print("\n  $words\n\n");
 				dump($this->state);
 				readline();
 			}

src/Automata/State.php

@@ -52,6 +52,7 @@ class State
 			$this->workCycleSelection->apply($word->value);
 
 			// TODO Handle other G commands
+
 			return;
 		}
 		if ($word->register === 'M') {