private void CalculateLookAhead(ProductionPatternAlternative alt, int pos)
{
var previous = new LookAheadSet(0);
var length = 1;
var flag = pos >= alt.Count;
if (!flag)
{
var pattern = alt.Pattern;
var elem = alt[pos];
var flag2 = elem.MinCount == elem.MaxCount;
if (flag2)
{
this.CalculateLookAhead(alt, pos + 1);
}
else
{
var first = this.FindLookAhead(elem, 1, new CallStack(), null);
var follow = this.FindLookAhead(alt, 1, pos + 1, new CallStack(), null);
var location = "at position " + Conversions.ToString(pos + 1);
var conflicts = this.FindConflicts(pattern.Name, location, first, follow);
while (conflicts.Size() > 0)
{
length++;
conflicts.AddAll(previous);
first = this.FindLookAhead(elem, length, new CallStack(), conflicts);
follow = this.FindLookAhead(alt, length, pos + 1, new CallStack(), conflicts);
first = first.CreateCombination(follow);
elem.LookAhead = first;
var flag3 = first.Intersects(conflicts);
if (flag3)
{
first = first.CreateIntersection(conflicts);
this.ThrowAmbiguityException(pattern.Name, location, first);
}
previous = conflicts;
conflicts = this.FindConflicts(pattern.Name, location, first, follow);
}
this.CalculateLookAhead(alt, pos + 1);
}
}
}
public bool Equals(ProductionPatternAlternative alt)
{
var flag = this.elements.Count != alt.elements.Count;
bool equals;
if (flag)
{
equals = false;
}
else
{
var num = this.elements.Count - 1;
for (var i = 0; i <= num; i++)
{
var flag2 = !this.elements[i].Equals(RuntimeHelpers.GetObjectValue(alt.elements[i]));
if (flag2)
{
return(false);
}
}
equals = true;
}
return(equals);
}