public IEnumerable <TermMatch> Matches(IMessageActivity input, object defaultValue)
{
var inputText = MessageActivityHelper.GetSanitizedTextInput(input);
// if the user hit enter on an optional prompt, then consider taking the current choice as a low confidence option
bool userSkippedPrompt = string.IsNullOrWhiteSpace(inputText) && (defaultValue != null || _noPreference != null);
if (userSkippedPrompt)
{
yield return(new TermMatch(0, inputText.Length, 1.0, defaultValue));
}
inputText = MessageActivityHelper.RemoveDiacritics(inputText);
foreach (var expression in _expressions)
{
double maxWords = expression.MaxWords;
foreach (Match match in expression.Expression.Matches(inputText))
{
var group1 = match.Groups[1];
var group2 = match.Groups[2];
object newValue;
if (group1.Success)
{
if (ConvertSpecial(expression.Value, defaultValue, out newValue))
{
yield return(new TermMatch(group1.Index, group1.Length, 1.0, newValue));
}
}
if (group2.Success)
{
var words = group2.Value.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries).Length;
var confidence = System.Math.Min(words / maxWords, 1.0);
if (ConvertSpecial(expression.Value, defaultValue, out newValue))
{
yield return(new TermMatch(group2.Index, group2.Length, confidence, newValue));
}
}
}
}
}
private int AddExpression(int n, object value, IEnumerable <string> terms, bool allowNumbers)
{
var orderedTerms = (from term in terms orderby term.Length descending select MessageActivityHelper.RemoveDiacritics(term)).ToArray();
var words = new StringBuilder();
var first = true;
int maxWords = 0;
if (orderedTerms.Length > 0)
{
maxWords = terms.Max(NumberOfWords);
foreach (var term in orderedTerms)
{
var nterm = term.Trim().Replace(" ", @"\s+");
if (nterm != "")
{
if (first)
{
first = false;
words.Append('(');
}
else
{
words.Append('|');
}
words.Append("(?:");
if (_wordStart.Match(nterm).Success&& _wordEnd.Match(nterm).Success)
{
words.Append($@"\b{nterm}\b");
}
else
{
words.Append(nterm);
}
words.Append(')');
}
}
}
if (first)
{
words.Append($@"(\b(?:{NOMATCH})");
}
words.Append(')');
var numbers = allowNumbers ? $"(\\b{n}\\b)" : NOMATCH;
var expr = $"{numbers}|{words}";
_expressions.Add(new ValueAndExpression(value, new Regex(expr.ToString(), RegexOptions.IgnoreCase), maxWords));
++n;
return(n);
}