public CustomParserAction(LanguageData language, ParserState state,
ExecuteActionMethod executeRef)
{
Language = language;
State = state;
ExecuteRef = executeRef;
Conflicts.UnionWith(state.BuilderData.Conflicts);
// Create default shift and reduce actions
foreach (var shiftItem in state.BuilderData.ShiftItems)
{
ShiftActions.Add(new ShiftParserAction(shiftItem));
}
foreach (var item in state.BuilderData.ReduceItems)
{
ReduceActions.Add(ReduceParserAction.Create(item.Core.Production));
}
}
//Find an LR item without hints compatible with term (either shift on term or reduce with term as lookahead);
// this item without hints would become our default. We assume that other items have hints, and when conditions
// on all these hints fail, we chose this remaining item without hints.
private ParserAction FindDefaultAction(ParserState state, BnfTerm term)
{
//First check reduce items
var reduceItems = state.BuilderData.ReduceItems.SelectByLookahead(term as Terminal);
foreach (var item in reduceItems)
{
if (item.Core.Hints.Count == 0)
{
return(ReduceParserAction.Create(item.Core.Production));
}
}
var shiftItem = state.BuilderData.ShiftItems.SelectByCurrent(term).FirstOrDefault();
if (shiftItem != null)
{
return(new ShiftParserAction(shiftItem));
}
//if everything failed, returned first reduce item
return(null);
}