public Token Expect(TokenClass clazz)
{
Token ret = null;
if (Accept(clazz, ref ret))
{
return(ret);
}
Token offender = ReadToken();
if (offender != null)
{
errorLog.AddError(ErrorType.ParserError, offender.Location,
"Unexpected '{0}' (Expected '{1}')",
offender.ToString(),
Token.ClassToString(clazz));
}
else
{
errorLog.AddError(ErrorType.ParserError, offender.Location,
"Unexpected end of file (Expected {0})",
Token.ClassToString(clazz));
throw new Exception("");
}
return(new Token(clazz, "", Location));
}
public override void Accept(BinaryExpression pattern)
{
switch (pattern.Operation)
{
case BinaryOperation.Or:
case BinaryOperation.And:
pattern.Left.Visit(this);
pattern.Right.Visit(this);
break;
default:
errorLog.AddError(ErrorType.ParserError, pattern.Location,
"Binary operator can not be used on patterns!");
break;
}
}
private Token NextToken()
{
char ch = (char)PeekChar();
switch (ch)
{
case '#':
return(ReadComment());
case '\'':
case '"':
return(ReadStringLiteral());
case '_':
return(ReadIdentifier());
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
return(ReadNumber());
case '+':
case '-':
case '*':
case '/':
case '.':
case '=':
case '<':
case '>':
case '~':
case '!':
case '&':
case '^':
case '|':
case '%':
case '@':
case '?':
return(ReadOperator());
case '{':
ReadChar();
return(new Token(TokenClass.OpenBrace, "{", location));
case '}':
ReadChar();
return(new Token(TokenClass.CloseBrace, "}", location));
case '(':
ReadChar();
return(new Token(TokenClass.OpenParan, "(", location));
case ')':
ReadChar();
return(new Token(TokenClass.CloseParan, ")", location));
case '[':
ReadChar();
return(new Token(TokenClass.OpenBracket, "[", location));
case ']':
ReadChar();
return(new Token(TokenClass.CloseBracket, "]", location));
case ';':
ReadChar();
return(new Token(TokenClass.SemiColon, ";", location));
case ':':
ReadChar();
return(new Token(TokenClass.Colon, ":", location));
case ',':
ReadChar();
return(new Token(TokenClass.Comma, ",", location));
default:
if (char.IsLetter(ch))
{
return(ReadIdentifier());
}
errorLog.AddError(ErrorType.LexerError, location, "Unexpected '{0}'",
(char)ReadChar());
return(null);
}
}
public override void Accept(IfStatement ifStmt)
{
errorLog.AddError(ErrorType.ParserError, ifStmt.Location,
"Statement not allowed outside function body!");
}
public override void Accept(UseStatement useStmt)
{
errorLog.AddError(ErrorType.ParserError, useStmt.Location,
"use statement not valid inside function body!");
}
