/// <summary>
/// Given a listener that has traversed the tree, extract all the data into a DFS.
/// </summary>
/// <param name="parsedState"></param>
/// <returns></returns>
private static DetectorFinalState BuildDFS(this FinalStatePatternListener parsedState)
{
var result = new DetectorFinalState();
result.FinalStateObjects.AddRange(parsedState.FSOs);
result.Criteria.Arguments.AddRange(parsedState.TopLevelCriteria);
return(result);
}
/// <summary>
/// Return a DFS parsed from the text. Throw if error during parsing.
/// </summary>
/// <param name="text"></param>
/// <returns></returns>
public static DetectorFinalState Parse(this string text)
{
// Lex.
var input = new AntlrInputStream(text);
var lexer = new FinalStatePatternLexer(input);
CommonTokenStream tokens = new CommonTokenStream(lexer);
// Parse, capture errors.
var parser = new FinalStatePatternParser(tokens);
var errors = new ErrorRecorder();
parser.AddErrorListener(errors);
var tree = parser.top_level();
if (errors.Errors.Count > 0)
{
string msg = "";
foreach (var e in errors.Errors)
{
msg += e;
}
throw new ArgumentException(msg);
}
// Convert to DFS
var traverser = new FinalStatePatternListener();
var walker = new ParseTreeWalker();
walker.Walk(traverser, tree);
// And collect the DFS
return(traverser.BuildDFS());
}
