Question

我仍然在编程语言项目中编写我的编程语言。打印完成，我做了输入，但它不起作用。这是我尝试输入的内容：

progress = []
command_libary = []
command_split = []
def split_command(command):
    command2 = command.split()
    for x in command2:
        command_split.extend(x)
    command_libary.extend(command)
def C05basic(command3):
    x = 0
    z = 0
    split_command(command3)
    if (command_split[z] == "p" and command_split[z + 1] == "r" and command_split[z + 2] == "i" and command_split[z + 3] == "n" and command_split[z + 4] == "t" and command_split[z + 5] == "("):
        if (command_split[z + 6] == '"' or command_split[z + 6] == "'" or command_split[z + 6] == "`"):
            for x in range(z + 7, len(command_split)):
                if ((command_split[x] == '"' or command_split[x] == "'" or command_split[x] == "`") and command_split[x + 1] == ')'):
                    break
                progress.extend(command_split[x])
            print ("".join(progress))
            z = z + 6 + len(progress)
            progress.pop()
    elif (command_split[z] == "i" and command_split[z + 1] == "n" and command_split[z + 2] == "p" and command_split[z + 3] == "u" and command_split[z + 4] == "t" and command_split[z + 5] == "("):
        if (command_split[z + 6] == '"' or command_split[z + 6] == "'" or command_split[z + 6] == "`"):
            for x in range(z + 7, len(command_split)):
                if ((command_split[x] == '"' or command_split[x] == "'" or command_split[x] == "`") and command_split[x + 1] == ')'):
                    break
                progress.extend(command_split[x])
            input ("".join(progress))
            z = z + 6 + len(progress)
            progress.pop()
    progress.pop()
    command_split.pop()    

C05basic("input('something')")

它给了我：

something #in input

但是当我使用时：

C05basic("print('something')")
C05basic("input('something')")

它给了我：

something
somethisomething'input('something #Not written by command input (, but by print)

Idk为什么......我做错了什么？

Answer 1

<强>分析

您尚未指定期望的内容。但是，我认为你有一些解析命令的想法。为了跟进你正在做的事情，我在C05basic顶部附近做了一个简单的调试插入：

def C05basic(command3):
    x = 0
    z = 0
    split_command(command3)
    print "TRACE command_split", command_split
    print "TRACE progress", progress

我从两个案例得到的输出：

1命令：

TRACE command_split ['i', 'n', 'p', 'u', 't', '(', "'", 's', 'o', 'm', 'e', 't', 'h', 'i', 'n', 'g', "'", ')']
TRACE progress []
something

2个命令：

TRACE command_split ['p', 'r', 'i', 'n', 't', '(', "'", 't', 'h', 'i', 's', 's', 't', 'u', 'f', 'f', "'", ')']
TRACE progress []
thisstuff
TRACE command_split ['p', 'r', 'i', 'n', 't', '(', "'", 't', 'h', 'i', 's', 's', 't', 'u', 'f', 'f', "'", 'i', 'n', 'p', 'u', 't', '(', "'", 's', 'o', 'm', 'e', 't', 'h', 'i', 'n', 'g', "'", ')']
TRACE progress ['t', 'h', 'i', 's', 's', 't', 'u']
thisstuthisstuff'input('something

非常简单，您无需控制数据列表和下标。结果是你截断，连接，重叠，并且通常错误处理第二个输入。

<强>建议

学习增量编程。这里的部分问题是你在测试任何东西之前编码得太多了。相反，写几行，确保它们有效，然后再添加更多。

学习基本调试。查看这个可爱的debug博客以获取帮助。

在深入学习之前了解新语言的基本功能。例如，由于您还没有学习基本的字符串操作，因此您很难阅读。例如，你的第一个大的 if 语句可以通过一个简单的字符串比较，一个针对常量的切片来大大改进：

if command_split[z: z+5] == "print":

逐个字符比较浪费了大量的时间和视觉空间。

解释器项目“输入” - Python-3.6

1 个答案: