public QueryTerms(string phrase)
{
Terms = QueryTerms.parse(phrase);
}
private static List <string> parse(string phrase)
{
List <string> terms = new List <string>();
if (string.IsNullOrEmpty(phrase))
{
return(terms);
}
phrase = " " + PublicMethods.verify_string(phrase) + " ";
string pattern = "\\s[\\+\\-]?\"[^\"]*\"\\s";
Dictionary <string, string> quotesDic = new Dictionary <string, string>();
MatchCollection matches = null;
while (true)
{
matches = string.IsNullOrEmpty(phrase) ? (MatchCollection)null : (new Regex(pattern)).Matches(phrase);
if (matches == null || matches.Count == 0)
{
break;
}
for (int i = 0; i < matches.Count; i++)
{
string key = PublicMethods.random_string(10);
quotesDic[key] = matches[i].Value;
phrase = phrase.Replace(matches[i].Value.Trim(), " " + key + " ");
}
}
phrase.Split(' ')
.Select(x => x.Trim())
.Where(x => !string.IsNullOrEmpty(x))
.Select(x => quotesDic.ContainsKey(x) ? quotesDic[x].Trim() : x)
.ToList()
.ForEach(x =>
{
string prefix = new[] { "+", "-" }.Where(c => x.StartsWith(c)).FirstOrDefault();
if (!string.IsNullOrEmpty(prefix))
{
x = x.Length > 1 ? x.Substring(1) : string.Empty;
}
if (string.IsNullOrEmpty(x))
{
return;
}
bool isQuote = x[0] == '"' && x[x.Length - 1] == '"';
if (isQuote)
{
if (x.Length <= 2)
{
return;
}
x = x.Substring(1, x.Length - 2).Trim();
}
new[] {
"+", "-", "&", "|", "!", "(", ")", "{", "}", "[", "]", "^", "\"", "~", ":", "/",
"\\", ".", ",", "،", "؛", "؟"
}.ToList().ForEach(c => x = x.Replace(c, " "));
x = x.Trim();
if (string.IsNullOrEmpty(x))
{
return;
}
isQuote = isQuote && x.IndexOf(" ") > 0;
if (isQuote)
{
x = "\"" + x + "\"";
}
if (!string.IsNullOrEmpty(prefix))
{
x = prefix + x;
}
if (!isQuote && x.IndexOf(" ") > 0)
{
terms.AddRange(QueryTerms.parse(x));
}
else
{
if (!isQuote && !(new[] { "?", "*" }).Any(c => x.IndexOf(c) >= 0))
{
x += "~1";
}
else if (isQuote)
{
x += "^";
}
terms.Add(x);
}
});
return(terms.Distinct().Where(t => !string.IsNullOrEmpty(t)).ToList());
}
