public static Regex FromPatternString(string pattern)
{
if (RegexCache.ContainsKey(pattern)) {
return RegexCache[pattern];
}
var lexer = new RegexLexer(
new Cache<TextReader, char>(new CharCacheSource(new StringReader(pattern)))
);
var parser = new RegexParser(lexer);
var regex = parser.Parse();
RegexCache.Add(pattern, regex);
return regex;
}
public RegexParser(RegexLexer lexer)
{
_lexer = lexer;
_lookaheadToken = _lexer.GetNextToken();
_regexStack.Clear();
}
