/// <summary>
/// Parse the input string and return a regular automaton
/// </summary>
/// <param name="pattern"></param>
/// <returns></returns>
public static RegularAutomaton parse(string pattern)
{
if (pattern == null)
{
throw new PatternParseException("Pattern can not be null");
}
if (!pattern.StartsWith("^"))
{
pattern = ".*" + pattern;
}
else
{
pattern = pattern.Substring(1);
}
if (!pattern.EndsWith("$"))
{
pattern = pattern + ".*";
}
else
{
if (pattern.Length > 0)
{
pattern = pattern.Substring(0, pattern.Length - 1);
}
}
Lexer lexer = new Lexer(pattern);
RegularState end = new FinalRegularState();
RegularState start = pAlt(lexer, end);
start.resolveGreedyEnd(new Set <RegularState>(), end);
RegularAutomaton auto = new RegularAutomaton();
auto.setStartState(start);
auto.setEndState(end);
if (lexer.token().type != Token.EOF)
{
throw new PatternParseException(String.Format("Garbage token '%s' at #%d", lexer.token().text, lexer
.charPos()));
}
return(auto);
}
private RegularPattern(string pattern)
: base(pattern)
{
automaton = Parser.parse(pattern);
}