这是我正在制作的编程语言的basic.py文件。目前它正在抛出一个错误。
STRING "HELLO WORLD"
string "Hey world!"
17 + 3
这是我传递数据的test.vil文件（我的编程语言叫做villar）：
IndexError: List index out of range结果，我在第62行得到/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package computercompany;
/**
*
* @author obliv_000
*/
public class StockItem
{
private String itemID;
private String itemDesc;
private double price;
private int quantity;
private int reOrderLevel;
public String getItemID()
{
return itemID;
}
public String getItemDesc()
{
return itemDesc;
}
public double getPrice()
{
return price;
}
public int getQuantity()
{
return quantity;
}
public int getReOrderLevel()
{
return reOrderLevel;
}
public StockItem(String itemsID, String itemsDesc, double p, int quant,
int rol)
{
itemID = itemsID;
itemDesc = itemsDesc;
quantity = quant;
reOrderLevel = rol;
price = p;
}
public void setPrice(double price)
{
this.price = price;
}
public void setQuantity(int quantity)
{
this.quantity = quantity;
}
public void setReOrderLevel(int reOrderLevel)
{
this.reOrderLevel = reOrderLevel;
}
public String toString()
{
return "itemID = " + getItemID() + ", itemDesc = " + getItemDesc() +
", price = " + getPrice() + ", quantify = " + getQuantity() +
", reOrderLevel = " + getReOrderLevel();
}
public String format()
{
return "The values for the following variables are:\nItemID: " +
getItemID() + "\nItemDesc: " + getItemDesc() + "\nPrice: " +
getPrice() + "\nQuantify: " + getQuantity() + "\nReOrderLevel: "
+ getReOrderLevel();
}
}
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package computercompany;
/**
*
* @author obliv_000
*/
public interface StockList
{
public StockLinkedList stock = new StockLinkedList();
public void addItem(StockItem item);
public void deleteItem(String itemID);
public void updateItemPrice(String itemID, double price);
public void updateItemQuantity(String itemID, int quantity);
public void updateReOrderLevel(String itemID, int reOrderLevel);
public String formatStockList(String list)
{
list = String.format
("ItemID Description Price Qnty Re-Order Level\n"
+ "****** *********** ***** **** **************\n");
return list;
}
public String formatReOrderList()
{
ListIterator<StockItem> iterf = ItemList.listIterator();
String reReOrderList = FormattedTitle;
while(iterf.hasNext())
{
StockItem temp = iterf.next;
int quant = temp.getQuantity();
int reorder = temp.getReOrderLevel();
if(quant<reorder)
{
formattedReOrder += iterf.next().format() + "\n";
}
}
}
ListIterator listIterator()
{
throw new UnsupportedOperationException("Not yet implemented");
}
}
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package computercompany;
/**
*
* @author obliv_000
*/
public class StockLinkedList<StockList>
{
private StockLinkedList<StockList> prevItem;
private StockItem myItem;
private StockLinkedList<StockList> nextItem;
public StockLinkedList(StockList item)
{
this(null, item, null);
}
public StockLinkedList(StockList item, StockLinkedList<StockList> previous,
StockLinkedList next)
{
myItem = item;
nextItem = next;
prevItem = previous;
}
}
public StockList getMyItem()
{
return myItem;
}
public StockLinkedList<StockList> getNextItem()
{
return nextItem;
}
public StockLinkedList<StockList> getPrevItem()
{
return prevItem;
}
public void setItem(StockList item)
{
myItem = item;
}
public void setPrevItem(StockLinkedList<StockList> previous)
{
prevItem = previous;
}
public void setNextItem(StockLinkedList<StockList> next)
{
nextItem = next;
}
}
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package computercompany;
import static computercompany.StockList.stock;
/**
*
* @author obliv_000
*/
public class StockListCLI
{
private StockList stock = null;
public StockListCLI(StockList stock)
{
}
// Displays main menu and gets valid option from user
public void doMenu()
{
}
// Obtain input for stock list operation
// and invoke operation
private void doAddItem()
{
stockList.add(item);
}
private void doDeleteItem()
{
Iterator<StockItem> itr = stockList.listIterator();
while(itr.hasNext())
{
StockItem item = itr.next();
if(item.getItemID().equals(itemID))
{
itr.remove();
break;
}
}
}
private void doUpdateItemPrice()
{
ListIterator itr = stock.listIterator();
while(itr.hasNext())
{
StockItem item = (StockItem)itr.next();
if(item.getItemID().equals(itemID))
{
item.setPrice(price);
break;
}
}
}
private void doUpdateItemQuantity()
{
ListIterator itr = stock.listIterator();
while(itr.hasNext())
{
StockItem item = (StockItem)itr.next();
if(item.getItemID().equals(itemID))
{
item.setReOrderLevel(reOrderLevel);
break;
}
}
}
private void doUpdateReOrderLevel()
{
StockLinkedList itr = stock.listIterator();
while(itr.setNextItem())
{
StockItem item = (StockItem)itr.next();
if(item.getItemID().equals(itemID))
{
item.setQuantity(quantity);
break;
}
}
}
// Display contents of stock list
private void doPrintStockList()
{
}
// Display contents of re-order list
private void doPrintReorderLIst()
{
}
}
。
你能帮助我吗？如果允许的话，我会喜欢如何改进它的建议。
答案 0 :(得分：3)
你已经有了这条线：
while(i < len(toks)):
parse函数中的。但是，在此while循环中，您访问toks[i+1]元素，该元素将在while循环的最后一次迭代中超出范围（如i == len(toks)-1和i+1 == len(toks)边界并抛出错误）。您需要将以上行更改为：
while(i < len(toks)-1):
以便最终迭代i == len(toks) - 2和i+1 == len(toks) - 1都在边界内。