public object VisitKeywords(XshdKeywords keywords)
{
if (keywords.Words.Count == 0)
{
return(Error(keywords, "Keyword group must not be empty."));
}
foreach (var keyword in keywords.Words)
{
if (string.IsNullOrEmpty(keyword))
{
throw Error(keywords, "Cannot use empty string as keyword");
}
}
var keyWordRegex = new StringBuilder();
// We can use "\b" only where the keyword starts/ends with a letter or digit, otherwise we don't
// highlight correctly. (example: ILAsm-Mode.xshd with ".maxstack" keyword)
if (keywords.Words.All(IsSimpleWord))
{
keyWordRegex.Append(@"\b(?>");
// (?> = atomic group
// atomic groups increase matching performance, but we
// must ensure that the keywords are sorted correctly.
// "\b(?>in|int)\b" does not match "int" because the atomic group captures "in".
// To solve this, we are sorting the keywords by descending length.
var i = 0;
foreach (var keyword in keywords.Words.OrderByDescending(w => w.Length))
{
if (i++ > 0)
{
keyWordRegex.Append('|');
}
keyWordRegex.Append(Regex.Escape(keyword));
}
keyWordRegex.Append(@")\b");
}
else
{
keyWordRegex.Append('(');
var i = 0;
foreach (var keyword in keywords.Words)
{
if (i++ > 0)
{
keyWordRegex.Append('|');
}
if (char.IsLetterOrDigit(keyword[0]))
{
keyWordRegex.Append(@"\b");
}
keyWordRegex.Append(Regex.Escape(keyword));
if (char.IsLetterOrDigit(keyword[keyword.Length - 1]))
{
keyWordRegex.Append(@"\b");
}
}
keyWordRegex.Append(')');
}
return(new HighlightingRule
{
Color = GetColor(keywords, keywords.ColorReference),
Regex = CreateRegex(keywords, keyWordRegex.ToString(), XshdRegexType.Default)
});
}
public object VisitKeywords(XshdKeywords keywords)
{
return(keywords.ColorReference.AcceptVisitor(this));
}