private void Visit(ASTNode node)
{
if (node == null)
{
return;
}
if (node.GetType() == typeof(ASTDeclareNode))
{
_VisitDeclareNode(node as ASTDeclareNode);
}
else if (node.GetType() == typeof(ASTVarNode))
{
_VisitVarNode(node as ASTVarNode);
}
else if (node.GetType() == typeof(ASTCompoundNode))
{
foreach (ASTNode n in (node as ASTCompoundNode).Children)
{
Visit(n);
}
}
else
{
Visit(node.LeftChild);
Visit(node.RightChild);
}
}
private object _Visit(ASTNode node)
{
if (node.GetType() == typeof(ASTBinopNode))
{
return(_BinOpVisit(node));
}
else if (node.GetType() == typeof(ASTDeclareNode))
{
_VisitDeclare(node as ASTDeclareNode);
return(0);
}
else if (node.GetType() == typeof(ASTUnaryNode))
{
return(_UnOpVisit(node as ASTUnaryNode));
}
else if (node.GetType() == typeof(ASTCompoundNode))
{
_CompoundVisit(node as ASTCompoundNode);
return(0);
}
else if (node.GetType() == typeof(ASTAssignNode))
{
_VisitAssign(node as ASTAssignNode);
return(0);
}
else if (node.GetType() == typeof(ASTVarNode))
{
if (!GLOBAL_SCOPE.ContainsKey(node.Value.Value))
{
throw new KeyNotFoundException("Variable does not exist! " + node.Value.Value);
}
else
{
return(GLOBAL_SCOPE[node.Value.Value]);
}
}
else if (node.GetType() == typeof(ASTNoopNode))
{
return(0);
}
else if (node.GetType() == typeof(ASTNumNode))
{
if (node.Value.Type == TokenType.INT_CONST)
{
return(Int32.Parse(node.Value.Value));
}
if (node.Value.Type == TokenType.FLOAT_CONST)
{
return(float.Parse(node.Value.Value));
}
}
throw new Exception("Unexpected node type" + node.GetType());
}