private static void ExpandState(GrammarCompilationContext context, IntermediateParserState state)
{
// Check for possible shifts.
foreach (var shifter in state.Items.Shifters)
{
var currentElement = shifter.Kernel.Element;
// Get all LR(1) items sharing the same grammar element, get or
// create the state that corresponds to the shifted items, and create
// a transition to that state.
var shiftedKernels = from item in state.Items
let kernel = item.Kernel
where kernel.Element == currentElement
select kernel.NextItem;
var kernelsArray = shiftedKernels.ToArray();
var nextState = context.GetOrCreateState(kernelsArray);
shifter.NextItem = nextState.Items.First(x => x.Kernel == shifter.Kernel.NextItem);
context.GetOrCreateTransition(state, currentElement, nextState);
if (!state.State.Actions.ContainsKey(currentElement))
{
var action = new ShiftParserAction(nextState.State);
var customActionElement = currentElement as CustomActionGrammarElement;
if (customActionElement != null)
action.CustomAction = customActionElement.Action;
state.State.Actions[currentElement] = action;
}
}
}
private static IntermediateParserState CreateInitialState(GrammarCompilationContext context, GrammarDefinition augmentedRoot)
{
// The initial state contains the very first LR(0) item, which is the augmented root '.Root'.
var initialItem = context.GrammarData.GrammarReductionsMapping[augmentedRoot][0].Lr0Items[0];
var initialState = context.GetOrCreateState(new [] { initialItem });
return initialState;
}
