private void LoadRegexCache()
{
const string weekdaysRegex = @"(Sun|Mon|Tue|Wed|Thu|Fri|Sat)";
const string monthDayRegex = @"((0?[1-9]|[1-2][0-9]|3[01])(st|nd|rd|th)?)";
var wordedMonthRegex =
"((Jan(uary)?)|(Feb(ruary)?)|(Mar(ch)?)|(Apr(il)?)|May|(Jun(e)?)|(Jul(y)?)|(Aug(ust)?)|(Sep(tember)?)|(Oct(ober?))|(Nov(ember)?)|(Dec(ember)?))";
wordedMonthRegex = $"({wordedMonthRegex}|{wordedMonthRegex.ToUpperInvariant()})";
const string numberedMonthRegex = @"((0?[1-9]|1[0-2]))";
const string yearRegex = "(19[0-9]{2}|[2-9][0-9]{3}|[0-9]{2})";
const string timeRegex = @"(\s+(2[0-3]|[0-1]?[0-9]):([0-5][0-9])(:(60|[0-5][0-9]))?)";
const string timezoneRegex = @"(([-\\+][0-9]{2}[0-5][0-9]|(?:UT|GMT|(?:E|C|M|P)(?:ST|DT)|[A-IK-Z])))";
var dateTimeFormats = new[]
{
$@"\s*{weekdaysRegex}?{monthDayRegex}[.\\/-]\s*{numberedMonthRegex}[.\\/-]\s*{yearRegex}{timeRegex}?{timezoneRegex}?",
$@"\s*{weekdaysRegex}?{monthDayRegex}[ .\\/-]{wordedMonthRegex}[ .\\/-]{yearRegex}{timeRegex}?{timezoneRegex}?",
$@"\s*{weekdaysRegex}?{numberedMonthRegex}[.\\/-]{yearRegex}[ .\\/-]{timeRegex}?{timezoneRegex}?",
$@"\s*{weekdaysRegex}?{wordedMonthRegex}[ .\\/-]{monthDayRegex}[ .\\/-]{timeRegex}?{timezoneRegex}?\s+{yearRegex}",
$@"\s*{wordedMonthRegex}\s*{yearRegex}([ .\\/-]{timeRegex}{timezoneRegex}?)?"
};
var streetAbbreviations = new[]
{
"Ave",
"Blvd",
"Bdwy",
"Cir",
"Cl",
"Ct",
"Cr",
"Dr",
"Gdn",
"Gdns",
"Gn",
"Gr",
"Ln",
"Mt",
"Pl",
"Pk",
"Rdg",
"Rd",
"Sq",
"St",
"Ter",
"Val"
};
var streetTypeRegexes = streetAbbreviations.Select(i =>
{
var regex = new StringBuilder("(\\s");
foreach (var c in i)
{
regex.Append($"[{c.ToString().ToUpperInvariant()}{c.ToString().ToLowerInvariant()}]");
}
regex.Append(".)");
return(regex.ToString());
}).ToArray();
// date/times
RegexCache.Add(new Regex(string.Join("|", dateTimeFormats), RegexOptions.Compiled));
// phone numbers
RegexCache.Add(new Regex(@"(([0]|((\+|00)[0-9]{1-3}))[0-9][0-9][0-9]\s*[0-9]\s*[0-9][0-9]\s*[0-9]\s*[0-9][0-9][0-9])",
RegexOptions.Compiled));
// nhs numbers
RegexCache.Add(new Regex(@"([0-9][0-9][0-9][ -]?[0-9][0-9][0-9][ -]?[0-9][0-9][0-9][0-9])", RegexOptions.Compiled));
RegexCache.Add(new Regex(@"([0-9][0-9][0-9][ -][0-9][0-9][0-9][0-9][ -][0-9][0-9][0-9])", RegexOptions.Compiled));
// email addresses
RegexCache.Add(new Regex(
@"((?:[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*|""(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])*"")@(?:(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?|[a-z0-9-]*[a-z0-9]:(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)\]))",
RegexOptions.Compiled));
// post codes
RegexCache.Add(new Regex(
$@"(([,\sa-zA-Z0-9]|{string.Join("|", streetTypeRegexes)})*[,]\s)?(([gG][iI][rR] {{0,}}0[aA]{{2}})|((([a-pr-uwyzA-PR-UWYZ][a-hk-yA-HK-Y]?[0-9][0-9]?)|(([a-pr-uwyzA-PR-UWYZ][0-9][a-hjkstuwA-HJKSTUW])|([a-pr-uwyzA-PR-UWYZ][a-hk-yA-HK-Y][0-9O][abehmnprv-yABEHMNPRV-Y])))\s*[0-9O][abd-hjlnp-uw-zABD-HJLNP-UW-Z]{{2}}))",
RegexOptions.Compiled));
}