static bool _SymEq(_LrtSymbol x, _LrtSymbol y)
{
if (ReferenceEquals(x, y))
{
return(true);
}
else if (ReferenceEquals(x, null) || ReferenceEquals(y, null))
{
return(false);
}
var lhs = x;
if (ReferenceEquals(lhs, null))
{
return(false);
}
var rhs = y;
if (ReferenceEquals(rhs, null))
{
return(false);
}
return(Equals(lhs.Id, rhs.Id));
}
static CfgDocument _ToLRTransitionGrammar(CfgDocument cfg, Lrfa lrfa, IProgress <CfgLalr1Progress> progress)
{
var result = new CfgDocument();
var closure = new List <Lrfa>();
var itemSets = new List <ICollection <LRItem> >();
lrfa.FillClosure(closure);
foreach (var p in closure)
{
itemSets.Add(p.AcceptSymbol);
}
_LrtSymbol start = null;
int j = 0;
foreach (var p in closure)
{
if (null != progress)
{
progress.Report(new CfgLalr1Progress(CfgLalr1Status.CreatingLookaheadGrammar, j));
}
int si = itemSets.IndexOf(p.AcceptSymbol, _LRItemSetComparer.Default);
foreach (var item in p.AcceptSymbol)
{
if (0 == item.RightIndex)
{
var next = item.RightIndex < item.Rule.Right.Count ? item.Rule.Right[item.RightIndex] : null;
var rule = item.Rule;
if (item.RightIndex < item.Rule.Right.Count)
{
int dst = -1;
Lrfa dsts;
if (p.Transitions.ContainsKey(rule.Left))
{
dsts = p.Transitions[rule.Left];
dst = itemSets.IndexOf(dsts.AcceptSymbol, _LRItemSetComparer.Default);
}
_LrtSymbol left = new _LrtSymbol(si, rule.Left, dst);
if (null == start)
{
start = left;
}
var right = new List <string>();
var pc = p;
foreach (var sym in rule.Right)
{
int s1 = itemSets.IndexOf(pc.AcceptSymbol, _LRItemSetComparer.Default);
var pt = pc.Transitions[sym];
int s2 = itemSets.IndexOf(pt.AcceptSymbol, _LRItemSetComparer.Default);
_LrtSymbol n = new _LrtSymbol(s1, sym, s2);
right.Add(n.ToString());
pc = pt;
}
result.Rules.Add(new CfgRule(left.ToString(), right));
}
}
}
++j;
}
result.StartSymbol = start.ToString();
return(result);
}
