4.2

jlox.iml

@@ -4,7 +4,6 @@
     <exclude-output />
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
-      <excludeFolder url="file://$MODULE_DIR$/.idea/copilot/chatSessions" />
     </content>
     <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />

src/Lox.java

@@ -4,9 +4,12 @@ import java.io.InputStreamReader;
 import java.nio.charset.Charset;
 import java.nio.file.Files;
 import java.nio.file.Paths;
+import java.util.List;
 import java.util.Scanner;
 
 public class Lox {
+    static boolean hadError = false;
+
     public static void main(String[] args) throws IOException {
         if (args.length > 1) {
             System.out.println("Usage: jlox [script]");
@@ -21,6 +24,9 @@ public class Lox {
     private static void runFile(String path) throws IOException {
         byte[] bytes = Files.readAllBytes(Paths.get(path));
         run(new String(bytes, Charset.defaultCharset()));
+        if (hadError) {
+            System.exit(65);
+        }
     }
 
     private static void runPrompt() throws IOException {
@@ -32,6 +38,7 @@ public class Lox {
             String line = reader.readLine();
             if (line == null) break;
             run(line);
+            hadError = false;
         }
     }
 
@@ -44,4 +51,13 @@ public class Lox {
 
         }
     }
+
+    static void error(int line, String message) {
+        report(line, "", message);
+    }
+
+    private static void report(int line, String where, String message) {
+        System.err.println("[" + line + "] " + where + ": " + message);
+        hadError = true;
+    }
 }

src/Token.java

@@ -0,0 +1,17 @@
+class Token {
+    final TokenType type;
+    final String lexeme;
+    final Object literal;
+    final int line;
+
+    Token(TokenType type, String lexeme, Object literal, int line) {
+        this.type = type;
+        this.lexeme = lexeme;
+        this.literal = literal;
+        this.line = line;
+    }
+
+    public String toString() {
+        return type + " " + lexeme + " " + literal;
+    }
+}

src/TokenType.java

@@ -0,0 +1,18 @@
+enum TokenType {
+    // Single-character tokens
+    LEFT_PAREN, RIGHT_PAREN, LEFT_BRACE, RIGHT_BRACE,
+    COMMA, DOT, MINUS, PLUS, SEMICOLON, SLASH, STAR,
+
+    // One or two character tokens
+    BANG, BANG_EQUAL, EQUAL, EQUAL_EQUAL,
+    GREATER, GREATER_EQUAL, LESS, LESS_EQUAL,
+
+    // Literals
+    IDENTIFIER, STRING, NUMBER,
+
+    // Keywords
+    AND, CLASS, ELSE, FALSE, FUN, FOR, IF, NIL, OR,
+    PRINT, RETURN, SUPER, THIS, TRUE, VAR, WHILE,
+
+    EOF
+}