/*
* This static call constructs a RegexTree from a regular expression
* pattern string and an option string.
*
* The method creates, drives, and drops a parser instance.
*/
internal static RegexTree Parse(string re, RegexOptions op)
{
int end;
var pcreOptions = TrimPcreRegexOption(re, out end);
var pattern = TrimDelimiters(re, end);
RegexParser p;
RegexNode root;
string[] capnamelist;
p = new RegexParser((op & RegexOptions.CultureInvariant) != 0 ? CultureInfo.InvariantCulture : CultureInfo.CurrentCulture);
p._options = op;
p.SetPattern(pattern);
p.CountCaptures();
p.Reset(op);
root = p.ScanRegex();
if (p._capnamelist == null)
capnamelist = null;
else
capnamelist = p._capnamelist.ToArray();
return new RegexTree(root, p._caps, p._capnumlist, p._captop, p._capnames, capnamelist, op);
}
/*
* Escapes all metacharacters (including (,),[,],{,},|,^,$,*,+,?,\, spaces and #)
*/
internal static string Unescape(string input)
{
for (int i = 0; i < input.Length; i++)
{
if (input[i] == '\\')
{
var sb = new StringBuilder();
RegexParser p = new RegexParser(CultureInfo.InvariantCulture);
int lastpos;
p.SetPattern(input);
sb.Append(input, 0, i);
do
{
i++;
p.Textto(i);
if (i < input.Length)
sb.Append(p.ScanCharEscape());
i = p.Textpos();
lastpos = i;
while (i < input.Length && input[i] != '\\')
i++;
sb.Append(input, lastpos, i - lastpos);
} while (i < input.Length);
return sb.ToString();
}
}
return input;
}
/*
* This static call constructs a flat concatenation node given
* a replacement pattern.
*/
internal static RegexReplacement ParseReplacement(string rep, Dictionary<int, int> caps, int capsize, Dictionary<string, int> capnames, RegexOptions op)
{
RegexParser p;
RegexNode root;
p = new RegexParser((op & RegexOptions.CultureInvariant) != 0 ? CultureInfo.InvariantCulture : CultureInfo.CurrentCulture);
p._options = op;
p.NoteCaptures(caps, capsize, capnames);
p.SetPattern(rep);
root = p.ScanReplacement();
return new RegexReplacement(rep, root, caps);
}