Finish chapter 7

java/com/craftinginterpreters/lox/Lox.java

@@ -9,7 +9,9 @@ import java.nio.file.Paths;
 import java.util.List;
 
 public class Lox {
+  private static final Interpreter interpreter = new Interpreter();
   static boolean hadError = false;
+  static boolean hadRuntimeError = false;
 
   public static void main(String[] args) throws IOException {
     if (args.length > 1) {
@@ -27,6 +29,8 @@ public class Lox {
     run(new String(bytes, Charset.defaultCharset()));
     if (hadError)
       System.exit(65);
+    if (hadRuntimeError)
+      System.exit(70);
   }
 
   private static void runPrompt() throws IOException {
@@ -53,7 +57,7 @@ public class Lox {
     if (hadError)
       return;
 
-    System.out.println(new AstPrinter().print(expression));
+    interpreter.interpret(expression);
   }
 
   static void error(int line, String message) {
@@ -73,4 +77,9 @@ public class Lox {
       report(token.line, " at '" + token.lexeme + "'", message);
     }
   }
+
+  static void runtimeError(RuntimeError error) {
+    System.err.println(error.getMessage() + "\n[line " + error.token.line + "]");
+    hadRuntimeError = true;
+  }
 }