//number→real_number |integer 产生实数或整数
public static Value eval_number(NonterminalStackElement number_node)
{
if (number_node.branches.Count != 1)
{
throw new ExecutorException("文法发生了变化", number_node.linenum);
}
else
{
StackElement number = (StackElement)number_node.branches[0];
if (number.type_code == 2)
{
IntStackElement int_number = (IntStackElement)number;
return(new IntValue("int", true, int_number.content, int_number.linenum));
}
else if (number.type_code == 5)
{
RealStackElement real_number = (RealStackElement)number;
return(new RealValue("real", true, real_number.content, real_number.linenum));
}
else
{
throw new ExecutorException("文法发生了变化", number_node.linenum);
}
}
}
public override string ToString()
{
string text = "";
if (type_code == 1)
{
IdentifierStackElement e = (IdentifierStackElement)this;
text += "第" + e.linenum + "行标识符";
text += e.content;
}
else if (type_code == 2)
{
IntStackElement e = (IntStackElement)this;
text += "第" + e.linenum + "行整数";
text += e.content;
}
else if (type_code == 3)
{
NonterminalStackElement e = (NonterminalStackElement)this;
text += "非终结符";
text += e.name;
//递归调用
foreach (StackElement s in e.branches)
{
text += Environment.NewLine;
for (int i = 1; i < s.layers; i++)
{
text += " ";
}
text += s.ToString();
}
}
else if (type_code == 4)
{
OtherTerminalStackElement e = (OtherTerminalStackElement)this;
text += "第" + e.linenum + "行终结符";
text += e.content;
}
else if (type_code == 5)
{
RealStackElement e = (RealStackElement)this;
text += "第" + e.linenum + "行实数";
text += e.content;
}
else if (type_code == 7)
{
CharStackElement e = (CharStackElement)this;
text += "第" + e.linenum + "行字符";
text += e.content;
}
else if (type_code == 8)
{
StringStackElement e = (StringStackElement)this;
text += "第" + e.linenum + "行字符串";
text += e.content;
}
else
{
StateStackElement e = (StateStackElement)this;
text += "状态" + e.state;
}
return(text);
}
private void recursiveAddNodes(StackElement e, TreeViewItem newItem)
{
try
{
if (e.type_code == 6)
{
throw new ParserException("这个表示状态的栈元素不应该出现在Tree的递归子结点中！");
}
else if (e.type_code == 1)
{
IdentifierStackElement ele = (IdentifierStackElement)e;
newItem.Header = "第" + ele.linenum + "行的标识符：" + ele.content;
}
else if (e.type_code == 2)
{
IntStackElement ele = (IntStackElement)e;
newItem.Header = "第" + ele.linenum + "行的整数：" + ele.content;
}
else if (e.type_code == 3)
{
NonterminalStackElement ele = (NonterminalStackElement)e;
newItem.Header = "非终结符：" + ele.name;
}
else if (e.type_code == 4)
{
OtherTerminalStackElement ele = (OtherTerminalStackElement)e;
newItem.Header = "第" + ele.linenum + "行的终结符：" + ele.content;
}
else if (e.type_code == 5)
{
RealStackElement ele = (RealStackElement)e;
newItem.Header = "第" + ele.linenum + "行的实数：" + ele.content;
}
else if (e.type_code == 7)
{
CharStackElement ele = (CharStackElement)e;
newItem.Header = "第" + ele.linenum + "行的字符：" + ele.content;
}
else if (e.type_code == 8)
{
StringStackElement ele = (StringStackElement)e;
newItem.Header = "第" + ele.linenum + "行的字符串：" + ele.content;
}
else
{
throw new ParserException("这是啥栈元素？");
}
//若是终结符，branches就是空，若不是非终结符，它也终究会走到末端叶子节点，也就是非终结符，然后递归终止
if (e.branches.Count != 0)
{
foreach (StackElement ele in e.branches)
{
TreeViewItem new_node = new TreeViewItem();
newItem.Items.Add(new_node);
recursiveAddNodes(ele, new_node);
}
}
}
catch (ParserException pe)
{
MessageBox.Show(pe.err_msg);
}
catch (Exception ee)
{
MessageBox.Show(ee.ToString());
}
}