/// <summary>
/// Create a range from the specified information.
/// </summary>
/// <param name="qualifier">The qualifier for the range.</param>
/// <param name="from">The lower limit (or value to compare) for the range.</param>
/// <param name="to">The upper limit for the range.</param>
/// <returns>The range that was created.</returns>
protected override DateRangeBroker CreateRange(SearchQualifierValue qualifier, DateTime?from = null, DateTime?to = null) =>
new DateRangeBroker
{
Qualifier = qualifier,
From = from,
To = to
};
/// <summary>
/// Create a range from the specified information.
/// </summary>
/// <param name="qualifier">The qualifier for the range.</param>
/// <param name="from">The lower limit (or value to compare) for the range.</param>
/// <param name="to">The upper limit for the range.</param>
/// <returns>The range that was created.</returns>
protected override Int32RangeBroker CreateRange(SearchQualifierValue qualifier, int?from = null, int?to = null) =>
new Int32RangeBroker
{
Qualifier = qualifier,
From = from,
To = to
};
/// <summary>
/// Create a range from the specified information.
/// </summary>
/// <param name="qualifier">The qualifier for the range.</param>
/// <param name="from">The lower limit (or value to compare) for the range.</param>
/// <param name="to">The upper limit for the range.</param>
/// <returns>The range that was created.</returns>
protected abstract TRange CreateRange(SearchQualifierValue qualifier,
TLimit?from = null, TLimit?to = null);
/// <summary>
/// Try to parse the specified text.
/// </summary>
/// <param name="text">The text to parse.</param>
/// <param name="result">The resulting range.</param>
/// <returns>True, if the text was parsed successfully; otherwise, false.</returns>
public bool TryParse(string text, out TRange result)
{
if (string.IsNullOrWhiteSpace(text))
{
result = CreateRange(SearchQualifierValue.None);
return(true);
}
SearchQualifierValue qualifier = SearchQualifierValue.Equals;
int fromLength = text.Length;
int fromPosition = 0;
int toPosition = -1;
TLimit?to = null;
switch (text[0])
{
case '>':
fromPosition++;
if (text.Length > 1 && text[1] == '=')
{
qualifier = SearchQualifierValue.GreaterThanOrEqualTo;
fromPosition++;
}
else
{
qualifier = SearchQualifierValue.GreaterThan;
}
fromLength -= fromPosition;
break;
case '<':
fromPosition++;
if (text.Length > 1 && text[1] == '=')
{
qualifier = SearchQualifierValue.LessThanOrEqualTo;
fromPosition++;
}
else
{
qualifier = SearchQualifierValue.LessThan;
}
fromLength -= fromPosition;
break;
case '=':
qualifier = SearchQualifierValue.Equals;
fromLength = text.Length - 1;
fromPosition++;
break;
default:
int index = text.IndexOf("..");
if (index >= 0)
{
qualifier = SearchQualifierValue.Between;
toPosition = index + 2;
fromLength = index;
}
break;
}
string toText = toPosition > 0 ? text.Substring(toPosition).Trim() : null;
string fromText = text.Substring(fromPosition, fromLength).Trim();
if (!TryParse(fromText, out TLimit from))
{
result = null;
return(false);
}
if (toText != null)
{
if (TryParse(toText, out TLimit tmp))
{
to = tmp;
}
else
{
result = null;
return(false);
}
}
result = CreateRange(qualifier, from, to);
return(true);
}
