/**
* 对某个AST节点求值，并打印求值过程。
* @param node
* @param indent 打印输出时的缩进量，用tab控制
* @return
*/
private int evaluate(IASTNode node, string indent)
{
int result = 0;
Console.WriteLine(indent + "Calculating: " + node.getType());
switch (node.getType())
{
case ASTNodeType.Programm:
foreach (IASTNode child in node.getChildren())
{
result = evaluate(child, indent + "\t");
}
break;
case ASTNodeType.Additive:
IASTNode child1 = node.getChildren()[0];
int value1 = evaluate(child1, indent + "\t");
IASTNode child2 = node.getChildren()[1];
int value2 = evaluate(child2, indent + "\t");
if (node.getText() == "+")
{
result = value1 + value2;
}
else
{
result = value1 - value2;
}
break;
case ASTNodeType.Multiplicative:
child1 = node.getChildren()[0];
value1 = evaluate(child1, indent + "\t");
child2 = node.getChildren()[1];
value2 = evaluate(child2, indent + "\t");
if (node.getText() == "*")
{
result = value1 * value2;
}
else
{
result = value1 / value2;
}
break;
case ASTNodeType.IntLiteral:
result = Convert.ToInt32(node.getText());
break;
default:
break;
}
Console.WriteLine(indent + "结果：" + result);
return(result);
}
private void dumpAST(IASTNode node, string indent)
{
Console.WriteLine(indent + node.getType() + " " + node.getText());
recurCount++;
if (recurCount < 9999) // 递归次数限制，防止过深递归
{
foreach (IASTNode childNode in node.getChildren())
{
dumpAST(childNode, indent + "\t");
}
}
else
{
Console.WriteLine("递归层数超过9999");
}
}
