public override Mode Match(string[] objs, ref MetaInfo meta, bool partial = true)
{
if (meta == null)
{
throw new ArgumentNullException(nameof(meta));
}
var res = new Mode().SetName(Name);
var left = objs.Length - meta.Count;
if (left == 0)
{
return(_atleast == 0 ? res : null);
}
meta.Branch();
Mode r;
int idx = 0;
if (_atmost > 0)
{
while (true)
{
if (idx >= _atmost)
{
break;
}
r = base.Match(objs, ref meta, true);
if (r == null)
{
break;
}
res.AddRange(r);
++idx;
}
}
else
{
while (true)
{
r = base.Match(objs, ref meta, true);
if (r == null)
{
break;
}
res.AddRange(r);
++idx;
}
}
#if DEBUG
Console.WriteLine($"{name} <= {res.Dump()}");
#endif
if (idx < _atleast)
{
meta.Rollback();
return(null);
}
meta.Pull();
return(res);
}
public override Mode Match(string[] objs, ref MetaInfo meta, bool partial = true)
{
if (meta == null)
{
throw new ArgumentNullException(nameof(meta));
}
#if DEBUG
Console.WriteLine($"{this.name} ");
#endif
var res = new Mode().SetName(Name);
var hasRes = false;
foreach (var possibility in Possibilities)
{
meta.Branch(); // Make a branch in case of resetting.
foreach (var thing in possibility)
{
var history = (meta.Count, thing.Name);
Mode r;
if (thing.HasRecur)
{
if (meta.Trace.Contains(history))
{
Console.WriteLine("Found Left Recursion. Dealed.");
r = null;
}
else
{
meta.Trace.Push(history);
r = thing.Match(objs, ref meta, true);
}
}
else
{
// DEBUG View: the trace of parsing.
#if DEBUG
meta.trace.Push(history);
#endif
r = thing.Match(objs, ref meta, true);
}
if (r == null)
{
// Do not match current possibility, then rollback.
res.Clear();
meta.Rollback();
goto ContinueForNewPossibility;
}
if (thing is Seq)
{
res.AddRange(r);
}
else
{
res.Add(r);
}
#if DEBUG
Console.WriteLine($"{thing.name} <= {r.Dump()}");
#endif
}
#if DEBUG
Console.WriteLine($"RETURN from {this.name} ");
#endif
hasRes = true;
break;
ContinueForNewPossibility:
;
}
if (!hasRes)
{
#if DEBUG
Console.WriteLine($"RETURN None from {this.name} ");
#endif
return(null);
}
meta.Pull();
var left = objs.Length - meta.Count;
if (partial || left == 0)
{
#if DEBUG
Console.WriteLine($"RETURN Some from {this.name}");
#endif
return(res);
}
#if DEBUG
Console.WriteLine($"RETURN None from {this.name} (No partial and do not match all)");
#endif
return(null);
}
