CfgDocument _LRFAToLRExtendedGrammar(_LRFA lrfa, IProgress <CfgLRProgress> progress)
{
var result = new CfgDocument();
var closure = new List <_LRFA>();
var itemSets = new List <_LR0ItemSet>();
lrfa.FillClosure(closure);
foreach (var p in closure)
{
itemSets.Add(p.Accept);
}
_LRExtendedSymbol start = null;
int j = 0;
foreach (var p in closure)
{
if (null != progress)
{
progress.Report(new CfgLRProgress(CfgLRStatus.CreatingLRExtendedGrammar, j));
}
int si = itemSets.IndexOf(p.Accept);
foreach (var item in p.Accept.Items)
{
if (0 == item.RightIndex)
{
var next = item.Next;
if (!item.IsEnd || item.IsNil)
{
int dst = -1;
_LRFA dsts;
if (p.Transitions.ContainsKey(item.Left))
{
dsts = p.Transitions[item.Left];
dst = itemSets.IndexOf(dsts.Accept);
}
_LRExtendedSymbol left = new _LRExtendedSymbol(si, item.Left, dst);
if (null == start)
{
start = left;
}
var right = new List <string>();
var pc = p;
foreach (var sym in item.Right)
{
int s1 = itemSets.IndexOf(pc.Accept);
var pt = pc.Transitions[sym];
int s2 = itemSets.IndexOf(pt.Accept);
_LRExtendedSymbol n = new _LRExtendedSymbol(s1, sym, s2);
right.Add(n.ToString());
pc = pt;
}
result.Rules.Add(new CfgRule(left.ToString(), right));
}
}
}
++j;
}
result.StartSymbol = start.ToString();
return(result);
}
_LRFA _ToLRFA(IProgress <CfgLRProgress> progress)
{
if (null != progress)
{
progress.Report(new CfgLRProgress(CfgLRStatus.ComputingStates, 0));
}
var moves = new Dictionary <KeyValuePair <_LR0ItemSet, string>, _LR0ItemSet>();
// TODO: this takes a long time sometimes
var map = new Dictionary <_LR0ItemSet, _LRFA>();
// create an augmented grammar - add rule {start} -> [[StartId]]
var ss = StartSymbol;
var start = new CfgRule(GetAugmentedStartId(ss), new string[] { ss });
var cl = new _LR0ItemSet();
cl.AddItem(new _LR0Item(start, 0));
_FillLRClosureInPlace(progress, cl);
var lrfa = new _LRFA();
lrfa.Accept = cl;
var items = cl.Items.Count;
map.Add(cl, lrfa);
var done = false;
int oc;
while (!done)
{
done = true;
var arr = new _LR0ItemSet[map.Keys.Count];
map.Keys.CopyTo(arr, 0);
for (var i = 0; i < arr.Length; ++i)
{
var itemSet = arr[i];
foreach (var item in itemSet.Items)
{
var next = item.Next;
if (!item.IsEnd)
{
_LR0ItemSet n;
var key = new KeyValuePair <_LR0ItemSet, string>(itemSet, next);
if (!moves.TryGetValue(key, out n))
{
n = _FillLRMove(itemSet, next, progress);
moves.Add(key, n);
}
if (!map.ContainsKey(n))
{
done = false;
var npda = new _LRFA();
npda.Accept = n;
map.Add(n, npda);
items += n.Items.Count;
if (null != progress)
{
progress.Report(new CfgLRProgress(CfgLRStatus.ComputingConfigurations, items));
}
}
map[itemSet].Transitions[next] = map[n];
}
}
}
if (!done)
{
oc = map.Count;
if (null != progress)
{
progress.Report(new CfgLRProgress(CfgLRStatus.ComputingStates, oc));
}
}
}
return(lrfa);
}
