main.dart

import 'dart:io';

import 'src/error/error.dart';
import 'src/error/error_reporter.dart';
import 'src/interpreter/interpreter.dart';
import 'src/interpreter/value.dart';
import 'src/lexer/lexer.dart';
import 'src/parser/parser.dart';
import 'src/semantic/analyzer.dart';
import 'src/semantic/resolver.dart';
import 'src/symbol/symbol.dart';


SymbolTable symbols = new SymbolTable();

Object run(String program) {
  try {
    Lexer lexer = new Lexer(program);

    var tokens = lexer.tokenize();
    if (ErrorReporter.hadError) exit(65);
    
    Parser parser = new Parser(tokens);

    var ast = parser.parse();
    if (ErrorReporter.hadError) exit(65);

    Resolver resolver = new Resolver(symbols);

    resolver.resolve(ast);
    if (ErrorReporter.hadError) exit(65);

    Analyzer analyzer = new Analyzer(symbols);
    analyzer.check(ast);
    if (ErrorReporter.hadError) exit(65);

    Interpreter interpreter = new Interpreter(symbols);
    Value result = interpreter.evaluate(ast);
    if (ErrorReporter.hadRuntimeError) exit(70);

    return result; 
  } on CompilerError catch (e) {
    ErrorReporter.report(e);
    return null;
  }
}

void runPrompt() {
  print('Decaf REPL v0.1');
  print('Hit Ctrl+C to exit\n');

  while (true) {
    stdout.write('decaf > ');
    String line = stdin.readLineSync();
    
    print(run(line));
  }
}

void runFile(String filename) {
  File file = new File(filename);

  if (!file.existsSync()) {
    print('File $filename does not exist.');
    exit(60);
  }

  run(file.readAsStringSync());
}

void main(List<String> args) {
  if (args.length > 1) {
    print('Usage : decaf [file]');
    exit(1);
  } else if (args.length == 1) {
    runFile(args[0]);
  } else {
    runPrompt();
  }
}