public static string Expand(this string source, params string[] args)
{
var output = source;
var tokens = new List <string>();
var pattern = new Regex(_patternStyle.TokenMatchPattern, RegexOptions.IgnoreCase);
var calls = new Stack <string>();
string callingToken = null;
while (pattern.IsMatch(output))
{
foreach (Match match in pattern.Matches(output))
{
var token = _patternStyle.TokenReplaceFilter(match.Value);
var tokenIndex = 0;
if (!tokens.Contains(token))
{
tokens.Add(token);
tokenIndex = tokens.Count - 1;
}
else
{
tokenIndex = tokens.IndexOf(token);
}
output = Regex.Replace(output, _patternStyle.OutputFilter(match.Value), "{" + tokenIndex + "}");
}
}
var newArgs = new List <string>();
foreach (var arg in args)
{
var newArg = arg;
var tokenPattern = new Regex(_patternStyle.TokenFilter(string.Join("|", tokens)));
while (tokenPattern.IsMatch(newArg))
{
foreach (Match match in tokenPattern.Matches(newArg))
{
var token = _patternStyle.TokenReplaceFilter(match.Value);
if (calls.Contains(string.Format("{0}:{1}", callingToken, token)))
{
throw new CircularReferenceException(string.Format("Circular Reference Detected for token '{0}'.", callingToken));
}
calls.Push(string.Format("{0}:{1}", callingToken, token));
callingToken = token;
newArg = Regex.Replace(newArg, _patternStyle.OutputFilter(match.Value), args[tokens.IndexOf(token)]);
}
}
newArgs.Add(newArg);
}
return(string.Format(output, newArgs.ToArray()));
}
private static string Explode(this string source, Regex pattern, PatternStyle patternStyle, Func <string, string> expansionFactory, TreeNode <string> parent)
{
var output = source;
while (output.HasChildren(pattern))
{
foreach (Match match in pattern.Matches(source))
{
var child = match.Value;
var token = patternStyle.TokenReplaceFilter(match.Value);
var thisNode = parent.Children.Add(token);
// if we have already encountered this token in this call tree, we have a circular reference
if (thisNode.CallTree.Contains(token))
{
throw new CircularReferenceException(string.Format("Circular Reference Detected for token '{0}'. Call Tree: {1}->{2}",
token,
string.Join("->", thisNode.CallTree.ToArray().Reverse()),
token));
}
// expand this match
var expandedValue = expansionFactory(token);
// Replace the match with the expanded value
child = Regex.Replace(child, patternStyle.OutputFilter(match.Value), expandedValue);
// Recursively expand the child until we no longer encounter nested tokens (or hit a circular reference)
child = child.Explode(pattern, patternStyle, expansionFactory, thisNode);
// finally, replace the match in the output with the fully-expanded value
output = Regex.Replace(output, patternStyle.OutputFilter(match.Value), child);
}
}
return(output);
}
private static string Explode(this string source, Regex pattern, PatternStyle patternStyle, Func<string, string> expansionFactory, TreeNode<string> parent)
{
var output = source;
while (output.HasChildren(pattern))
{
foreach (Match match in pattern.Matches(source))
{
var child = match.Value;
var token = patternStyle.TokenReplaceFilter(match.Value);
var thisNode = parent.Children.Add(token);
// if we have already encountered this token in this call tree, we have a circular reference
if (thisNode.CallTree.Contains(token))
throw new CircularReferenceException(string.Format("Circular Reference Detected for token '{0}'. Call Tree: {1}->{2}",
token,
string.Join("->", thisNode.CallTree.ToArray().Reverse()), token));
// expand this match
var expandedValue = expansionFactory(token);
// Replace the match with the expanded value
child = Regex.Replace(child, patternStyle.OutputFilter(match.Value), expandedValue);
// Recursively expand the child until we no longer encounter nested tokens (or hit a circular reference)
child = child.Explode(pattern, patternStyle, expansionFactory, thisNode);
// finally, replace the match in the output with the fully-expanded value
output = Regex.Replace(output, patternStyle.OutputFilter(match.Value), child);
}
}
return output;
}
