private ParserActionType GetActionTypeForOperation(TokenAst current)
{
ITerminal thisTerm = current.Terminal;
for (int i = _stack.Count - 2; i >= 0; i--)
{
if (_stack[i].Node == null)
{
continue;
}
IGrammarTerm term = _stack[i].Node.Term;
if (!term.IsSet(TermOptions.IsOperator))
{
continue;
}
ITerminal prevTerm = term as ITerminal;
if (prevTerm.Precedence == thisTerm.Precedence)
{
return(thisTerm.Associativity == Associativity.Left ? ParserActionType.Reduce : ParserActionType.Shift);
}
ParserActionType result = prevTerm.Precedence > thisTerm.Precedence ? ParserActionType.Reduce : ParserActionType.Shift;
return(result);
}
return(ParserActionType.Shift);
}
private AstNode CreateNode(ActionRecord reduceAction, SourceSpan sourceSpan, AstNodeList childNodes)
{
IGrammarTerm nonTeminal = reduceAction.NonTerminal;
AstNode result;
AstNodeArgs args = new AstNodeArgs(nonTeminal, sourceSpan, childNodes);
Type ntNodeType = nonTeminal.NodeType ?? typeof(AstNode);
bool isList = nonTeminal.IsSet(TermOptions.IsList);
if (isList && childNodes.Count > 1 && childNodes[0].Term == nonTeminal)
{
result = childNodes[0];
AstNode newChild = childNodes[childNodes.Count - 1];
newChild.Parent = result;
result.ChildNodes.Add(newChild);
return(result);
}
if (nonTeminal.IsSet(TermOptions.IsStarList) && childNodes.Count == 1)
{
childNodes = childNodes[0].ChildNodes;
}
if (!isList && !nonTeminal.IsSet(TermOptions.IsPunctuation) && childNodes.Count == 1)
{
Type childNodeType = childNodes[0].Term.NodeType ?? typeof(AstNode);
if (childNodeType == ntNodeType || childNodeType.IsSubclassOf(ntNodeType))
{
return(childNodes[0]);
}
}
result = null;
if (ntNodeType == typeof(AstNode))
{
result = new AstNode(args);
}
else
{
ConstructorInfo ctor = ntNodeType.GetConstructor(new Type[] { typeof(AstNodeArgs) });
if (ctor == null)
{
throw new Exception("Failed to located constructor: " + ntNodeType.ToString() + "(AstNodeArgs args)");
}
result = (AstNode)ctor.Invoke(new object[] { args });
}
return(result);
}
internal AstNodeArgs(IGrammarTerm term, SourceSpan span, AstNodeList childNodes)
{
Term = term;
Span = span;
ChildNodes = childNodes;
}
internal AstNodeArgs(IGrammarTerm term, SourceSpan span, AstNodeList childNodes)
{
Term = term;
Span = span;
ChildNodes = childNodes;
}
