Files
crafting-interpreters/jlox/src/main/java/xyz/ctsk/lox/Lox.java
2022-09-03 20:22:29 +02:00

63 lines
1.6 KiB
Java

package xyz.ctsk.lox;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Paths;
public class Lox {
private static boolean hadError = false;
private static void run(String source) {
var scanner = new Scanner(source);
scanner.scanTokens().forEach(System.out::println);
}
static void error(int line, String message) {
report(line, "", message);
}
private static void report(int line, String where, String message) {
System.err.printf("[line %d] Error %s: %s%n", line, where, message);
hadError = true;
}
private static void runPrompt() throws IOException {
var input = new InputStreamReader(System.in);
var reader = new BufferedReader(input);
while (true) {
System.out.println("> ");
String line = reader.readLine();
if (line == null) break;
run(line);
hadError = false;
}
};
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 printUsage() {
System.out.println("Usage: jlox [script]");
}
public static void main(String[] args) throws IOException {
if (args.length == 0) {
runPrompt();
} else if (args.length == 1) {
runFile(args[0]);
} else {
printUsage();
}
}
}