/********************************************************
*********以下是创建语法树所用的各类节点的申请***********
********************************************************/
/********************************************************/
/* 函数名 newRootNode */
/* 功 能 创建语法树根节点函数 */
/* 说 明 该函数为语法树创建一个新的根结点 */
/* 并将语法树节点成员初始化 */
/********************************************************/
public static TreeNode NewRootNode()
{
TreeNode t = new TreeNode();
/* 指定新语法树节点t成员:结点类型nodekind为语句类型ProK */
t.NodeKind = NodeKind.proK;
/* 指定新语法树节点t成员:源代码行号lineno为全局变量lineno */
t.LineNum = -1;
t.LevelNum = 0;
t.PositionInLevel = 1;
/* 函数返回语法树根节点指针t */
return t;
}
/// <summary>
/// param -> type-specifier ID array
/// </summary>
private void process18()
{
elementStack.Push(new LL1StackElement(true, NonTerminalType.Array,18));
elementStack.Push(new LL1StackElement(true, NonTerminalType.ID2,18));
elementStack.Push(new LL1StackElement(true, NonTerminalType.TypeSpecifier,18));
//新建参数节点
TreeNode t = new TreeNode(NodeKind.paramK, currentToken.LineNumber, (TokenType)currentToken.TokenTypes, currentLevelNum, currentScope);
OperateTreeStack(t);
}
/// <summary>
/// declaration -> fun-declaration
/// </summary>
private void Process6()
{
elementStack.Push(new LL1StackElement(true, NonTerminalType.FunDeclaration,6));
//建立函数声明节点
TreeNode t = new TreeNode(NodeKind.funK, currentToken.LineNumber, (TokenType)currentToken.TokenTypes, currentLevelNum, currentScope);
//
OperateTreeStack(t);
}
/// <summary>
/// declaration -> var-declaration
/// </summary>
private void Process5()
{
//
elementStack.Push(new LL1StackElement(true, NonTerminalType.VarDeclaration,5));
//建立变量声明新节点
TreeNode t = new TreeNode(NodeKind.varK, currentToken.LineNumber, (TokenType)currentToken.TokenTypes, currentLevelNum, currentScope);
//
OperateTreeStack(t);
}
/// <summary>
/// 处理树栈。
/// </summary>
/// <param name="t"></param>
private void OperateTreeStack(TreeNode t)
{
//取出栈顶元素
TreeNode curTop = treeStack.Peek();
if (curTop.LevelNum == currentLevelNum)//同一层
{ //同一层，兄弟节点
//指向兄弟节点
curTop.Sibling = t;
treeStack.Pop();
//增加儿子节点
curTop = treeStack.Peek();
curTop.AddChild(t);
//curtop. = t;
//指向父亲节点
t.Father = curTop;
treeStack.Push(t);
}
else if (curTop.LevelNum +1 == currentLevelNum) //当前元素是栈顶元素的下一层
{
curTop.AddChild(t);
//curtop. = t;
//指向父亲节点
t.Father = curTop;
treeStack.Push(t);
}
else if (curTop.LevelNum - 1 == currentLevelNum)//当前元素是栈顶元素的上一层
{
//儿子出栈
treeStack.Pop();
//当前节点的兄弟节点
curTop = treeStack.Peek();
//指向兄弟节点
curTop.Sibling = t;
treeStack.Pop();
//增加儿子节点
curTop = treeStack.Peek();
curTop.AddChild(t);
//curtop. = t;
//指向父亲节点
t.Father = curTop;
treeStack.Push(t);
}
}
/// <summary>
/// 加孩子，从1开始编号
/// </summary>
/// <param name="treenode"></param>
public void AddChild(TreeNode treeNode)
{
++ChildNum;
Child[ChildNum] = treeNode;
}
