public void EmptyExpressionsAreNotValid(string filter)
{
FilterLexer lexer = new FilterLexer(filter);
Assert.IsNotNull(lexer);
Assert.Count(0, lexer.Tokens);
Assert.IsNull(lexer.GetNextToken());
Assert.IsNull(lexer.LookAhead(1));
Assert.IsNull(lexer.GetNextToken());
}
private static FilterToken LookAhead(FilterLexer lexer, int index)
{
FilterToken token = lexer.LookAhead(index);
if (token != null && token.Type == FilterTokenType.Error)
{
throw new FilterParseException(token.Text);
}
return(token);
}
public void GetNextTokenLookAheadWithOneToken()
{
FilterLexer lexer = new FilterLexer("a");
Assert.IsNotNull(lexer);
Assert.Count(1, lexer.Tokens);
Assert.IsNull(lexer.LookAhead(0));
Assert.IsNotNull(lexer.LookAhead(1));
Assert.IsNull(lexer.LookAhead(2));
Assert.IsNotNull(lexer.GetNextToken());
Assert.IsNotNull(lexer.LookAhead(0));
Assert.IsNull(lexer.LookAhead(1));
Assert.IsNull(lexer.GetNextToken());
Assert.IsNull(lexer.LookAhead(0));
Assert.IsNull(lexer.LookAhead(1));
}
public void GetNextTokenAndLookAheadWithTwoTokens()
{
FilterLexer lexer = new FilterLexer("a:");
Assert.IsNotNull(lexer);
Assert.Count(2, lexer.Tokens);
Assert.IsNull(lexer.LookAhead(0));
Assert.IsNotNull(lexer.LookAhead(1));
Assert.IsNotNull(lexer.LookAhead(2));
Assert.IsNull(lexer.LookAhead(3));
Assert.IsNotNull(lexer.GetNextToken());
Assert.IsNotNull(lexer.LookAhead(0));
Assert.IsNotNull(lexer.LookAhead(1));
Assert.IsNull(lexer.LookAhead(2));
Assert.IsNotNull(lexer.GetNextToken());
Assert.IsNotNull(lexer.LookAhead(0));
Assert.IsNull(lexer.LookAhead(1));
Assert.IsNull(lexer.LookAhead(2));
Assert.IsNull(lexer.GetNextToken());
Assert.IsNull(lexer.LookAhead(0));
Assert.IsNull(lexer.LookAhead(1));
}
