static void Main(string[] args)
{
var tokenMapper = new ExpressionTokenMapper();
var tokenizer = new ExpressionTokenizer(tokenMapper);
var parser = new ExpressionParser(tokenizer);
while (true)
{
var line = Console.ReadLine();
try
{
bool ret = parser.ParseExpression(line);
Console.WriteLine("Expression is valid.");
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
}
static void Main(string[] args)
{
var tokenMapper = new ExpressionTokenMapper();
var tokenizer = new ExpressionTokenizer(tokenMapper);
var parser = new ExpressionParser(tokenizer);
while (true)
{
var line = Console.ReadLine();
try
{
bool ret = parser.ParseExpression(line);
Console.WriteLine("Expression is valid...");
}
catch (ParseException ex)
{
if (ex.Reason == EExceptionReason.UnmatchedError)
{
Console.WriteLine($"Parse error at position {ex.Position}: Unmatched \"{ex.Token}\" in expression.");
}
else if (ex.Reason == EExceptionReason.StartExpressionError)
{
Console.WriteLine($"Parse error at position {ex.Position}: An expression must start with a digit or a \"(\".");
}
}
catch (InvalidTokenException ex)
{
var message = $"Unexpected input after \"{ex.TokenData}\" at position {ex.Position}: "
+ $"expected: \")\",\"+\",\"-\",\"*\",\"/\" or end of expression, but found \"{ex.PeekedData}\".";
Console.WriteLine(message);
}
catch (TokenizationException ex)
{
Console.WriteLine($"Error at position {ex.CharacterIndex}: \"{ex.Input}\" is not a valid input.");
}
}
}
