public static IEnumerable <T> FilterObjectsByNames <T>(IEnumerable <T> items, IList <string> patterns, Func <T, string> get_name, bool ignorecase, FilterAction action)
{
if (patterns == null || patterns.Count < 1)
{
// nothing to filter just return the items
foreach (T item in items)
{
yield return(item);
}
}
else
{
// Create the caches for fast matches of regexes
var regexes = new List <System.Text.RegularExpressions.Regex>();
var compare = ignorecase ? StringComparer.InvariantCultureIgnoreCase : StringComparer.InvariantCulture;
var nonregexes = new HashSet <string>(compare);
foreach (var pattern in patterns)
{
if (WildcardHelper.ContainsWildcard(pattern))
{
// If it contains a wildcard transform it into a regex
var regex = WildcardHelper.GetRegexForWildcardPattern(pattern, ignorecase);
regexes.Add(regex);
}
else
{
// if it doesn't contain a wildcard then perform simple string equality
nonregexes.Add(pattern);
}
}
// the caches are set up, let's process each item
foreach (var item in items)
{
string name = get_name(item);
// does it match any of the patterns
// we test nonregexes first on the assumption that it's faster than checking regexes
bool matches = (nonregexes.Contains(name)) || (regexes.Any(regex => regex.IsMatch(name)));
if (action == FilterAction.Exclude && !matches)
{
// For exclude, non-match means this is a desired item so yield it
yield return(item);
}
else if (action == FilterAction.Include && matches)
{
// For include, match means this is a desired item so yield it
yield return(item);
}
}
}
}
public static IEnumerable <string> ExcludeByName(IEnumerable <string> items, IList <string> pattens, bool ignorecase)
{
return(WildcardHelper.FilterObjectsByNames(items, pattens, System.IO.Path.GetFileName, ignorecase, FilterAction.Exclude));
}
