private AstNode CreateNode(ActionRecord reduceAction, SourceSpan sourceSpan, AstNodeList childNodes)
{
NonTerminal nonTeminal = reduceAction.NonTerminal;
AstNode result;
AstNodeArgs args = new AstNodeArgs(nonTeminal, sourceSpan, childNodes);
Type defaultNodeType = _context.Compiler.Data.DefaultNodeType;
Type ntNodeType = nonTeminal.NodeType ?? defaultNodeType ?? 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 ?? defaultNodeType ?? 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);
}
