private string FormatToken(RuntimeGrammar grammar, Msg msg)
{
if (msg.Id == PredefinedTokens.Eoi)
{
return("end of file");
}
string result = grammar.SymbolName(msg.Id);
if (!result.StartsWith("'") && msg.Value != null)
{
result = msg.Value.ToString();
}
return(result);
}
private object DefaultMerge(
int token,
object alt1,
object alt2,
object context,
IStackLookback<Msg> stackLookback)
{
var result = alt2;
#if true
Debug.WriteLine("------------------------------");
Debug.WriteLine(
"Default merging of token {0} values in state {1}:",
(object)runtimeGrammar.SymbolName(token),
stackLookback.GetParentState());
Debug.WriteLine(" '{0}'", alt1);
Debug.WriteLine(" and");
Debug.WriteLine(" '{0}'", alt2);
Debug.WriteLine(" into the value: '{0}'", (object)result);
#endif
return result;
}
public void WriteGraph(IGraphView view, RuntimeGrammar grammar, int[] stateToSymbol)
{
var allAccessibleByLayer = GetAllNodes().GroupBy(state => state.Layer);
var layers = Enumerable
.Range(0, currentLayer + 1)
.Select(i => new List <GssNode <T> >(2))
.ToList();
foreach (var group in allAccessibleByLayer)
{
layers[group.Key].AddRange(group);
}
view.BeginDigraph("Gss");
view.SetGraphProperties(rankDir: RankDir.RightToLeft);
for (int layerIndex = 0; layerIndex != layers.Count; ++layerIndex)
{
var layer = layers[layerIndex];
view.BeginCluster(layerIndex.ToString());
view.SetGraphProperties(style: Style.Dotted, label: "U" + layerIndex);
view.SetNodeProperties(shape: Shape.Circle);
for (int nodeIndex = 0; nodeIndex != layer.Count; ++nodeIndex)
{
view.AddNode(
Tuple.Create("s", layerIndex, nodeIndex),
label: StateName(layer[nodeIndex]));
}
view.EndCluster();
}
view.SetNodeProperties(shape: Shape.Rect);
int linkIndex = 0;
for (int layerIndex = 0; layerIndex != layers.Count; ++layerIndex)
{
var layer = layers[layerIndex];
for (int nodeIndex = 0; nodeIndex != layer.Count; ++nodeIndex)
{
var from = layer[nodeIndex];
if (from.State < 0)
{
continue;
}
int token = stateToSymbol[from.State];
var link = from.FirstLink;
while (link != null)
{
var to = link.LeftNode;
view.AddNode(Tuple.Create("t", linkIndex), grammar.SymbolName(token));
view.AddEdge(
Tuple.Create("s", layerIndex, nodeIndex),
Tuple.Create("t", linkIndex)
);
view.AddEdge(
Tuple.Create("t", linkIndex),
Tuple.Create("s", to.Layer, layers[to.Layer].IndexOf(to))
);
++linkIndex;
link = link.NextLink;
}
}
}
view.EndDigraph();
}
public IReceiver <Msg> Next(Msg envelope)
{
stateStack.BeginEdit();
int id = envelope.Id;
MsgData data = envelope.FirstData;
START:
ParserAction action = LookaheadAction(id);
switch (action.Kind)
{
case ParserActionKind.Fail:
if (isVerifier)
{
return(null);
}
// ReportUnexpectedToken(msg, stateStack.PeekTag());
return(RecoverFromError(envelope));
case ParserActionKind.Resolve:
id = action.RolvedToken;
while (true)
{
if (data.Token == id)
{
// Successfully resolved to a particular token
goto START;
}
data = data.Next;
if (data == null)
{
// Desired token was not present in Msg
goto case ParserActionKind.Fail;
}
}
case ParserActionKind.Fork:
case ParserActionKind.Conflict:
logging.Write(
new LogEntry
{
Severity = Severity.Error,
Location = envelope.Location,
HLocation = envelope.HLocation,
Message = "Hit parser conflict on token " + grammar.SymbolName(envelope.Id)
});
return(null);
case ParserActionKind.Shift:
{
stateStack.Push(action.State, producer.CreateLeaf(envelope, data));
break;
}
case ParserActionKind.ShiftReduce:
{
TNode value = producer.CreateLeaf(envelope, data);
do
{
stateStack.Push(-1, value);
this.currentRule = grammar.Productions[action.ProductionId];
stateStack.Start = stateStack.Count - currentRule.PatternTokens.Length;
value = producer.CreateBranch(
currentRule,
stateStack.PeekTail(currentRule.PatternTokens.Length),
(IStackLookback <TNode>)stateStack);
stateStack.Pop(currentRule.PatternTokens.Length);
action = ParserAction.Decode(actionTable(stateStack.PeekTag(), currentRule.OutcomeToken));
}while (action.Kind == ParserActionKind.ShiftReduce);
if (action.Kind == ParserActionKind.Fail)
{
return(null);
}
Debug.Assert(action.Kind == ParserActionKind.Shift);
stateStack.Push(action.State, value);
break;
}
case ParserActionKind.Accept:
producer.Result = stateStack.Peek();
return(FinalReceiver <Msg> .Instance);
default:
throw new InvalidOperationException("Internal error: Unsupported parser action");
}
stateStack.EndEdit();
this.priorInput = envelope;
return(this);
}
public IReceiver <Msg> Next(Msg envelope)
{
gss.BeginEdit();
N.Clear();
var front = gss.FrontArray;
MsgData data = envelope.FirstData;
do
{
int lookahead = data.Token;
Actor(lookahead);
Reducer(lookahead);
if (accepted)
{
int count = gss.Count;
for (int i = 0; i != count; ++i)
{
var node = front[i];
if (IsAccepting(node.State))
{
producer.Result = node.FirstLink.Label;
break;
}
}
}
var termValue = producer.CreateLeaf(envelope, data);
N[GetNKey(lookahead, gss.CurrentLayer + 1)] = termValue;
for (int i = 0; i != gss.Count; ++i)
{
var frontNode = front[i];
// Plan shift
var shift = GetShift(frontNode.State, lookahead);
if (shift >= 0)
{
Q.Enqueue(new PendingShift(frontNode, shift, lookahead));
}
// Shift and plan reduce
var action = GetShiftReduce(frontNode.State, lookahead);
if (action.Kind == ParserActionKind.ShiftReduce)
{
PlanShiftReduce(
frontNode,
lookahead,
termValue,
action.ProductionId,
action.Size);
}
}
data = data.Next;
}while (data != null);
gss.PushLayer();
Shifter();
// Run reducer again to complete
// shift-reduce and goto-reduce actions.
Reducer();
#if DIAGNOSTICS
if (!isVerifier)
{
using (var graphView = new GvGraphView("GlrState" + gss.CurrentLayer + ".gv"))
{
gss.WriteGraph(graphView, grammar, stateToPriorToken);
}
}
#endif
if (gss.IsEmpty)
{
if (accepted)
{
return(FinalReceiver <Msg> .Instance);
}
if (isVerifier)
{
return(null);
}
gss.Undo(0); // restore state before the current input token
{
var message = new StringBuilder();
message
.Append("Unexpected token ")
.Append(grammar.SymbolName(envelope.Id))
.Append(" in state stacks: {");
bool firstStack = true;
for (int i = 0; i != gss.Count; ++i)
{
var node = gss.FrontArray[i];
if (firstStack)
{
firstStack = false;
}
else
{
message.Append(", ");
}
message.Append("[");
var n = node;
bool firstState = true;
while (true)
{
if (firstState)
{
firstState = false;
}
else
{
message.Append(", ");
}
message.Append(n.State);
if (n.State == 0)
{
break;
}
n = n.FirstLink.LeftNode;
}
message.Append("]");
}
message.Append("}");
logging.Write(
new LogEntry
{
Severity = Severity.Verbose,
Location = envelope.Location,
HLocation = envelope.HLocation,
Message = message.ToString()
});
}
return(RecoverFromError(envelope));
}
gss.EndEdit();
this.priorInput = envelope;
return(this);
}