/// <summary>
/// Attempts to parse a filter string from the command line to a RootFilter
/// </summary>
/// <remarks>
/// Filter string is of the format:
/// [DependencyOperator][Filter]
///
/// where [DependencyOperator] is implicitly all dependencies or "+" for all dependencies and dependents
/// where [Filter] is a filter of form [filter type]='[filter value]' or [negation]([Filter]) or [negation]([Filter][operator][Filter])
/// where [negation] is either "~" or empty
/// where [operator] is "and" or "or"
/// </remarks>
/// <param name="rootFilter">Filter that was parsed</param>
/// <param name="error">Error from parsing filter string</param>
/// <returns>true if parsing was successful</returns>
public bool TryParse(out RootFilter rootFilter, out FilterParserError error)
{
Contract.Ensures(Contract.Result <bool>() ^ Contract.ValueAtReturn <RootFilter>(out rootFilter) == null);
Contract.Ensures(Contract.Result <bool>() ^ Contract.ValueAtReturn <FilterParserError>(out error) != null);
rootFilter = null;
if (string.IsNullOrEmpty(m_expression))
{
error = new FilterParserError(0, ErrorMessages.NullEmptyFilter);
return(false);
}
SkipWhitespace();
try
{
rootFilter = ParseRootFilter();
// Ensure parsing the filter consumed the entire string
if (m_position != m_expression.Length)
{
rootFilter = null;
error = new FilterParserError(m_position, ErrorMessages.ExpectedEndOfFilter, StartGroup, EndGroup);
return(false);
}
}
catch (FilterParserException ex)
{
error = ex.Error;
return(false);
}
error = null;
return(true);
}
/// <summary>
/// Creates a FilterParserException from an error
/// </summary>
public FilterParserException(FilterParserError error)
{
Error = error;
}