public static TemporaryGroup CreateRootGroup(IParsingTreeNode oldNode, ParserNode omitPatternRoot, Location locFrom, Location locTo, out ParserNode prevGrammarNode, out bool insideOmittedFragment)
{
insideOmittedFragment = false;
var oldGroup = oldNode as IParsingTreeGroup;
if (oldGroup == null || oldGroup.Location > locFrom)
{
throw new InvalidOperationException();
}
prevGrammarNode = null;
var newGroup = new TemporaryReparsingGroup(oldNode, (oldNode as ParsingTreeNode).GrammarNode, locFrom, locTo, null, null);
var newGroupChild = CreateItemToReparse(oldGroup, newGroup, locFrom, locTo);
int depth = 0;
while (newGroupChild != null)
{
if (newGroupChild.GrammarNode == omitPatternRoot)
{
insideOmittedFragment = true;
}
prevGrammarNode = newGroup.GrammarNode;
oldGroup = newGroupChild.OldGroup;
newGroup = newGroupChild;
newGroupChild = CreateItemToReparse(oldGroup, newGroup, locFrom, locTo);
depth++;
}
// TODO: [Portable.Parser.Impl.ParsingTreeNode.CreateRootGroup] to think about possible parsing directions when reparsing
//var lastTakenChild = newGroup.Childs.LastOrDefault();
//if (lastTakenChild != null)
// prevGrammarNode = ((ParsingTreeNode)lastTakenChild).GrammarNode;
prevGrammarNode = newGroup.Parent.GrammarNode;
return(newGroup);
}
private static TemporaryReparsingGroup CreateItemToReparse(IParsingTreeGroup oldGroup, TemporaryReparsingGroup parent, Location fromLoc, Location toLoc)
{
IParsingTreeGroup prevGroup = null;
foreach (var oldChild in oldGroup.Childs)
{
if (oldChild.Location <= fromLoc)
{
var childTerm = oldChild as IParsingTreeTerminal;
var childGroup = oldChild as IParsingTreeGroup;
if (childTerm != null)
{
prevGroup = null;
if (childTerm.To > fromLoc)
{
break; // this term need to be reparsed and so forth
}
else
{
// skip
}
}
else if (childGroup != null)
{
prevGroup = childGroup;
}
else
{
throw new NotImplementedException("");
}
}
else
{
break; // prev child item need to be processed
}
}
return(prevGroup == null ? null : new TemporaryReparsingGroup(
prevGroup, (prevGroup as ParsingTreeNode).GrammarNode, fromLoc, toLoc, parent, null
));
}
