public _LR0Item(CfgRule rule, int rightIndex)
{
Left = rule.Left;
_hashCode = Left.GetHashCode();
if (!rule.IsNil)
{
Right = new string[rule.Right.Count];
rule.Right.CopyTo(Right, 0);
for (var i = 0; i < Right.Length; i++)
{
var right = rule.Right[i];
_hashCode ^= right.GetHashCode();
Right[i] = right;
}
}
else
{
Right = new string[] { }
};
_hashCode ^= rightIndex;
RightIndex = rightIndex;
}
public IList <CfgMessage> TryToLR1ParseTable(out CfgLR1ParseTable parseTable, LRTableKind kind = LRTableKind.Lalr1, IProgress <CfgLRProgress> progress = null)
{
var result = new List <CfgMessage>();
var start = GetAugmentedStartId(StartSymbol);
var lrfa = _ToLRFA(progress);
var trnsCfg = _LRFAToLRExtendedGrammar(lrfa, progress);
trnsCfg.RebuildCache();
var closure = new List <_LRFA>();
parseTable = new CfgLR1ParseTable();
var itemSets = new List <_LR0ItemSet>();
lrfa.FillClosure(closure);
var i = 0;
foreach (var p in closure)
{
itemSets.Add(p.Accept);
parseTable.Add(new Dictionary <string, (int RuleOrStateId, string Left, string[] Right)>());
++i;
}
i = 0;
foreach (var p in closure)
{
foreach (var trn in p.Transitions)
{
var idx = closure.IndexOf(trn.Value);
parseTable[i].Add(
trn.Key,
(idx, null, null)
);
}
foreach (var item in p.Accept.Items)
{
if (item.IsEnd && Equals(item.Left, start))
{
parseTable[i].Add(
"#EOS",
(-1, null, null));
}
}
++i;
}
var follows = trnsCfg.FillFollows();
// work on our reductions now
// each rule has a follows set associated with it
var map = new Dictionary <CfgRule, ICollection <string> >(_Lalr1MergeRuleComparer.Default);
foreach (var rule in trnsCfg.Rules)
{
ICollection <string> f;
if (!map.TryGetValue(rule, out f))
{
map.Add(rule, follows[rule.Left]);
}
else
{
foreach (var o in follows[rule.Left])
{
if (!f.Contains(o))
{
f.Add(o);
}
}
}
}
var j = 0;
foreach (var mapEntry in map)
{
if (null != progress)
{
progress.Report(new CfgLRProgress(CfgLRStatus.ComputingReductions, j));
}
var rule = mapEntry.Key;
var lr = rule.IsNil?_LRExtendedSymbol.Parse(rule.Left):_LRExtendedSymbol.Parse(rule.Right[rule.Right.Count - 1]);
var left = _LRExtendedSymbol.Parse(rule.Left).Id;
var right = new List <string>();
foreach (var s in rule.Right)
{
right.Add(_LRExtendedSymbol.Parse(s).Id);
}
var newRule = new CfgRule(left, right);
if (newRule.IsNil)
{
lr.To = lr.From;
}
if (!Equals(left, start))
{
foreach (var f in mapEntry.Value)
{
// build the rule data
var rr = new string[newRule.Right.Count];
for (var ri = 0; ri < rr.Length; ri++)
{
rr[ri] = newRule.Right[ri];
}
var iid = _LRExtendedSymbol.Parse(f).Id;
(int RuleOrStateId, string Left, string[] Right)tuple;
var rid = Rules.IndexOf(newRule);
var newTuple = (RuleOrStateId : rid, Left : newRule.Left, Right : rr);
// this gets rid of duplicate entries which crop up in the table
if (!parseTable[lr.To].TryGetValue(iid, out tuple))
{
parseTable[lr.To].Add(iid,
newTuple);
}
else
{
if (null == tuple.Right)
{
var nr = Rules[rid];
var msg = new CfgMessage(ErrorLevel.Warning, CfgErrors.ShiftReduceConflict, string.Format("Shift-Reduce conflict on rule {0}, token {1}", nr, iid), nr.Line, nr.Column, nr.Position, FileOrUrl);
if (!result.Contains(msg))
{
result.Add(msg);
}
}
else
{
if (rid != tuple.RuleOrStateId)
{
var nr = Rules[rid];
var msg = new CfgMessage(ErrorLevel.Error, CfgErrors.ReduceReduceConflict, string.Format("Reduce-Reduce conflict on rule {0}, token {1}", nr, iid), nr.Line, nr.Column, nr.Position, FileOrUrl);
if (!result.Contains(msg))
{
result.Add(msg);
}
}
}
}
}
}
++j;
}
return(result);
}
public IList <CfgMessage> TryToGlrParseTable(out CfgGlrParseTable parseTable, LRTableKind kind = LRTableKind.Lalr1, IProgress <CfgLRProgress> progress = null)
{
var result = new List <CfgMessage>();
var start = GetAugmentedStartId(StartSymbol);
var lrfa = _ToLRFA(progress);
var trnsCfg = _LRFAToLRExtendedGrammar(lrfa, progress);
trnsCfg.RebuildCache();
var closure = new List <_LRFA>();
parseTable = new CfgGlrParseTable();
var itemSets = new List <_LR0ItemSet>();
lrfa.FillClosure(closure);
var i = 0;
foreach (var p in closure)
{
itemSets.Add(p.Accept);
parseTable.Add(new Dictionary <string, ICollection <(int RuleOrStateId, string Left, string[] Right)> >());
++i;
}
i = 0;
foreach (var p in closure)
{
foreach (var trn in p.Transitions)
{
var idx = closure.IndexOf(trn.Value);
ICollection <(int RuleOrStateId, string Left, string[] Right)> pcol;
if (!parseTable[i].TryGetValue(trn.Key, out pcol))
{
pcol = new List <(int RuleOrStateId, string Left, string[] Right)>();
parseTable[i].Add(trn.Key, pcol);
}
pcol.Add(
(idx, null, null)
);
}
foreach (var item in p.Accept.Items)
{
if (item.IsEnd && Equals(item.Left, start))
{
ICollection <(int RuleOrStateId, string Left, string[] Right)> pcol;
if (!parseTable[i].TryGetValue("#EOS", out pcol))
{
pcol = new List <(int RuleOrStateId, string Left, string[] Right)>();
parseTable[i].Add("#EOS", pcol);
}
pcol.Add(
(-1, null, null));
//break;
}
}
++i;
}
var follows = trnsCfg.FillFollows();
// work on our reductions now
// each rule has a follows set associated with it
var map = new Dictionary <CfgRule, ICollection <string> >(_Lalr1MergeRuleComparer.Default);
foreach (var rule in trnsCfg.Rules)
{
ICollection <string> f;
if (!map.TryGetValue(rule, out f))
{
map.Add(rule, follows[rule.Left]);
}
else
{
foreach (var o in follows[rule.Left])
{
if (!f.Contains(o))
{
f.Add(o);
}
}
}
}
var j = 0;
foreach (var mapEntry in map)
{
if (null != progress)
{
progress.Report(new CfgLRProgress(CfgLRStatus.ComputingReductions, j));
}
var rule = mapEntry.Key;
var lr = rule.IsNil ? _LRExtendedSymbol.Parse(rule.Left) : _LRExtendedSymbol.Parse(rule.Right[rule.Right.Count - 1]);
var left = _LRExtendedSymbol.Parse(rule.Left).Id;
var right = new List <string>();
foreach (var s in rule.Right)
{
right.Add(_LRExtendedSymbol.Parse(s).Id);
}
var newRule = new CfgRule(left, right);
if (newRule.IsNil)
{
lr.To = lr.From;
}
if (!Equals(left, start))
{
foreach (var f in mapEntry.Value)
{
// build the rule data
var rr = new string[newRule.Right.Count];
for (var ri = 0; ri < rr.Length; ri++)
{
rr[ri] = newRule.Right[ri];
}
var iid = _LRExtendedSymbol.Parse(f).Id;
var rid = Rules.IndexOf(newRule);
var newTuple = (RuleOrStateId : rid, Left : newRule.Left, Right : rr);
// this handles duplicate entries which crop up in the table
ICollection <(int RuleOrStateId, string Left, string[] Right)> pcol;
if (!parseTable[lr.To].TryGetValue(iid, out pcol))
{
pcol = new List <(int RuleOrStateId, string Left, string[] Right)>();
parseTable[lr.To].Add(iid, pcol);
}
var found = false;
foreach (var t in pcol)
{
if (t.Left == newTuple.Left && t.RuleOrStateId == newTuple.RuleOrStateId)
{
if ((t.Right == null && newTuple.Right == null) ||
t.Right?.Length == newTuple.Right?.Length)
{
if (t.Right != null)
{
found = true;
for (var ii = 0; ii < t.Right.Length; ++ii)
{
if (t.Right[ii] != newTuple.Right[ii])
{
found = false;
break;
}
}
}
}
}
if (found)
{
break;
}
}
if (!found)
{
pcol.Add(newTuple);
}
}
}
++j;
}
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);
}