private TokenType getTokenType()
{
if (characterStream.isNextCharWhiteSpace())
{
return(TokenType.WHITESPACE);
}
else if (shouldReadIdentifier())
{
return(TokenType.IDENTIFIER);
}
else if (characterStream.isNextCharOperator())
{
return(TokenType.OPERATOR);
}
else if (characterStream.isNextCharLeftParentheses())
{
return(TokenType.LEFT_PARENTHESES);
}
else if (characterStream.isNextCharRightParentheses())
{
return(TokenType.RIGHT_PARENTHESES);
}
else
{
throw new UnknownSymbolException("Unknown Symbol: " + characterStream.peek());
}
}