private Path BacktrackingFindMatches(
Edge e,
IParseTree current,
out bool match
)
{
// Variable "input" can be either one of three types:
// AstParserParser.DeclContext
// AstParserParser.AttrContext
// terminal
// Go through all children and match.
var state = e.To;
if (Piggy._debug_information)
{
System.Console.Error.WriteLine(
"BacktrackingFindMatches"
+ " state " + state
+ " input " + (current == null ? "''" : current.GetText().Truncate(30) + " " + current.GetType()));
}
if (current == null)
{
if (state.Owner.IsFinalState(state))
{
var p = new Path(e, current);
match = true;
return(p);
}
if (e.IsEmpty || e.IsCode || e.IsText)
{
var r = BacktrackingFindMatches(e.To, current, out match);
if (match)
{
if (r == null)
{
r = new Path(e, current);
}
else
{
var p = new Path(e, current, r);
}
if (Piggy._debug_information)
{
System.Console.Error.WriteLine("returning " + r);
}
return(r);
}
}
}
else if (current as AstParserParser.NodeContext != null ||
current as AstParserParser.AttrContext != null)
{
if (e.IsEmpty || e.IsCode || e.IsText)
{
var r = BacktrackingFindMatches(e.To, current, out match);
if (match)
{
if (r == null)
{
r = new Path(e, current);
}
else
{
var p = new Path(e, current, r);
}
if (Piggy._debug_information)
{
System.Console.Error.WriteLine("returning " + r);
}
return(r);
}
}
else if (e.IsNot)
{
// To match this, go up to parent and scan all children
IParseTree parent = current.Parent;
bool found = false;
foreach (var child in parent.ChildrenForward())
{
if (child as AstParserParser.AttrContext != null)
{
if (child.GetChild(0).GetText() == e.Input)
{
found = true;
break;
}
}
}
if (!found)
{
IParseTree n = current;
var r = BacktrackingFindMatches(e.To, n, out match);
if (match)
{
if (r == null)
{
r = new Path(e, current);
}
else
{
var p = new Path(e, current, r);
}
if (Piggy._debug_information)
{
System.Console.Error.WriteLine("returning " + r);
}
return(r);
}
}
}
else if (e.IsAny)
{
IParseTree n = NextSibling(current);
var r = BacktrackingFindMatches(e.To, n, out match);
if (match)
{
if (r == null)
{
r = new Path(e, current);
}
else
{
var p = new Path(e, current, r);
}
if (Piggy._debug_information)
{
System.Console.Error.WriteLine("returning " + r);
}
return(r);
}
}
else
{
// Delve down into child and step through
// all siblings.
IParseTree n = current.GetChild(0);
var r = BacktrackingFindMatches(e, n, out match);
if (match)
{
if (Piggy._debug_information)
{
System.Console.Error.WriteLine("returning " + r);
}
return(r);
}
}
}
else
{
// Terminal.
if (e.IsEmpty || e.IsCode || e.IsText)
{
var r = BacktrackingFindMatches(e.To, current, out match);
if (match)
{
if (r == null)
{
r = new Path(e, current);
}
else
{
var p = new Path(e, current, r);
}
if (Piggy._debug_information)
{
System.Console.Error.WriteLine("returning " + r);
}
return(r);
}
}
else if (e.IsAny)
{
}
else if (e.IsNot)
{
// To match this, go up to parent and scan all children
IParseTree parent = current.Parent;
bool found = false;
foreach (var child in parent.ChildrenForward())
{
if (child as AstParserParser.AttrContext != null)
{
if (child.GetChild(0).GetText() == e.Input)
{
found = true;
break;
}
}
}
if (!found)
{
IParseTree n = current;
var r = BacktrackingFindMatches(e.To, n, out match);
if (match)
{
if (r == null)
{
r = new Path(e, current);
}
else
{
var p = new Path(e, current, r);
}
if (Piggy._debug_information)
{
System.Console.Error.WriteLine("returning " + r);
}
return(r);
}
}
}
else if (e.Input == current.GetText())
{
IParseTree n = Next(current);
var r = BacktrackingFindMatches(e.To, n, out match);
if (match)
{
if (r == null)
{
r = new Path(e, current);
}
else
{
var p = new Path(e, current, r);
}
if (Piggy._debug_information)
{
System.Console.Error.WriteLine("returning " + r);
}
return(r);
}
}
else if (e.Input == "<" && "(" == current.GetText())
{
IParseTree n = Next(current);
var r = BacktrackingFindMatches(e.To, n, out match);
if (match)
{
if (r == null)
{
r = new Path(e, current);
}
else
{
var p = new Path(e, current, r);
}
if (Piggy._debug_information)
{
System.Console.Error.WriteLine("returning " + r);
}
return(r);
}
}
else if (e.Input == ">" && ")" == current.GetText())
{
IParseTree n = Next(current);
var r = BacktrackingFindMatches(e.To, n, out match);
if (match)
{
if (r == null)
{
r = new Path(e, current);
}
else
{
var p = new Path(e, current, r);
}
if (Piggy._debug_information)
{
System.Console.Error.WriteLine("returning " + r);
}
return(r);
}
}
else if (e.Input == "*")
{
IParseTree n = Next(current);
var r = BacktrackingFindMatches(e.To, n, out match);
if (match)
{
if (r == null)
{
r = new Path(e, current);
}
else
{
var p = new Path(e, current, r);
}
if (Piggy._debug_information)
{
System.Console.Error.WriteLine("returning " + r);
}
return(r);
}
}
else if (e.Input.StartsWith("$\""))
{
var pattern = e.Input.Substring(2);
pattern = pattern.Substring(0, pattern.Length - 1);
try
{
var ch = e.Input;
if (e.AstList.Count() > 1)
{
;
}
//throw new Exception("Cannot compute interpolated pattern because there are multiple paths through the DFA with this edge.");
var attr = e.AstList.First();
pattern = ReplaceMacro(attr);
}
catch (Exception ex)
{
Console.WriteLine("Cannot perform substitution in pattern with string.");
Console.WriteLine("Pattern " + pattern);
Console.WriteLine(ex.Message);
throw ex;
}
pattern = pattern.Replace("\\", "\\\\");
var re = new Regex(pattern);
var tvaltext = current.GetText();
tvaltext = tvaltext.Substring(1);
tvaltext = tvaltext.Substring(0, tvaltext.Length - 1);
var matched = re.Match(tvaltext);
var result = matched.Success;
if (result)
{
IParseTree n = Next(current);
var r = BacktrackingFindMatches(e.To, n, out match);
if (match)
{
if (r == null)
{
r = new Path(e, current);
}
else
{
var p = new Path(e, current, r);
}
if (Piggy._debug_information)
{
System.Console.Error.WriteLine("returning " + r);
}
return(r);
}
}
}
}
if (Piggy._debug_information)
{
System.Console.Error.WriteLine("fail");
}
match = false;
return(null);
}
