public Scanner(SourceReader source, ErrorHandler errorHandler)
{
Source = source;
ErrorHandler = errorHandler;
SymbolTokens.Add("(", Token.Types.LParen);
SymbolTokens.Add(")", Token.Types.RParen);
SymbolTokens.Add("+", Token.Types.OpPlus);
SymbolTokens.Add("-", Token.Types.OpMinus);
SymbolTokens.Add("/", Token.Types.OpDivide);
SymbolTokens.Add("*", Token.Types.OpMultiply);
SymbolTokens.Add("<", Token.Types.OpLess);
SymbolTokens.Add("=", Token.Types.OpEquals);
SymbolTokens.Add("&", Token.Types.OpAnd);
SymbolTokens.Add("!", Token.Types.OpNot);
SymbolTokens.Add(";", Token.Types.LineTerm);
SymbolTokens.Add(":", Token.Types.Colon);
SymbolTokens.Add(":=", Token.Types.OpAssignment);
SymbolTokens.Add("..", Token.Types.OpRange);
KeywordTokens.Add("var", Token.Types.KwVar);
KeywordTokens.Add("int", Token.Types.KwInt);
KeywordTokens.Add("string", Token.Types.KwString);
KeywordTokens.Add("bool", Token.Types.KwBool);
KeywordTokens.Add("for", Token.Types.KwFor);
KeywordTokens.Add("end", Token.Types.KwEnd);
KeywordTokens.Add("in", Token.Types.KwIn);
KeywordTokens.Add("do", Token.Types.KwDo);
KeywordTokens.Add("read", Token.Types.KwRead);
KeywordTokens.Add("print", Token.Types.KwPrint);
KeywordTokens.Add("assert", Token.Types.KwAssert);
EscapeCharacters.Add('"', '"');
EscapeCharacters.Add('\'', '\'');
EscapeCharacters.Add('n', '\n');
EscapeCharacters.Add('t', '\t');
EscapeCharacters.Add('\\', '\\');
}
public TypeCheckerVisitor(ErrorHandler errors, StmtList statements)
{
Errors = errors;
SymbolTable = new SymbolTable();
Checker = new TypeChecker(errors);
RootStmtList = statements;
}
public TypeChecker(ErrorHandler errors)
{
Errors = errors;
intTypeBindings = new Dictionary<Operator, ExprType>()
{
{ Operator.Plus, ExprType.IntType },
{ Operator.Minus, ExprType.IntType },
{ Operator.Divide, ExprType.IntType },
{ Operator.Times, ExprType.IntType },
{ Operator.Equals, ExprType.BoolType },
{ Operator.Less, ExprType.BoolType }
};
boolTypeBindings = new Dictionary<Operator, ExprType>()
{
{ Operator.Equals, ExprType.BoolType },
{ Operator.And, ExprType.BoolType },
{ Operator.Not, ExprType.BoolType },
{ Operator.Less, ExprType.BoolType }
};
stringTypeBindings = new Dictionary<Operator, ExprType>()
{
{ Operator.Plus, ExprType.StringType },
{ Operator.Equals, ExprType.BoolType },
{ Operator.Less, ExprType.BoolType }
};
typeBindings = new Dictionary<ExprType, Dictionary<Operator, ExprType>>()
{
{ ExprType.IntType, intTypeBindings },
{ ExprType.BoolType, boolTypeBindings },
{ ExprType.StringType, stringTypeBindings }
};
}
static void Main(string[] args)
{
if (args.Length == 0)
{
Console.WriteLine("Usage: interpreter filename [-p]\n\n-p: Print the parsed abstract syntax tree.");
return;
}
string filename = args[0];
StreamReader sourceFile;
try
{
sourceFile = new StreamReader(filename);
}
catch (Exception)
{
Console.WriteLine("File " + filename + " not found.");
return;
}
SourceReader source = new SourceReader(sourceFile);
ErrorHandler errors = new ErrorHandler();
Scanner lexer = new Scanner(source, errors);
Parser parser = new Parser(lexer, errors);
StmtList ast = parser.Parse();
TypeCheckerVisitor checker = new TypeCheckerVisitor(errors, ast);
SymbolTable SymbolTable = checker.TypeCheck();
if (errors.HasErrors)
{
Console.WriteLine("Given program contains following errors:");
foreach (Error error in errors.GetErrors())
{
Console.WriteLine(error);
}
return;
}
if (args.Length > 1 && args[1] == "-p")
{
Console.WriteLine("Parsed abstact syntax tree:");
AstPrinterVisitor printer = new AstPrinterVisitor(ast);
printer.Print();
Console.WriteLine();
Console.WriteLine("Program output:");
}
ExecutorVisitor executor = new ExecutorVisitor(SymbolTable, ast);
try
{
executor.Execute();
}
catch (RuntimeException e)
{
Console.WriteLine("Runtime exception: " + e.Message);
}
}
public Parser(Scanner scanner, ErrorHandler errors)
{
Scanner = scanner;
Errors = errors;
CurrentToken = Scanner.GetNextToken();
}
public void Initialize()
{
errors = new ErrorHandler();
}