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我正在开发一个使用 pyparsing 解析命令行的程序。它使用 readline 库来提供命令编辑和补全。

在应用程序的上下文中，有效的命令行是路径（可选），后跟命令名称（可选）和一些参数（也是可选的）。

为了提供命令补全，应用程序解析命令行以查看要补全的元素是路径、命令还是补全。Readline 给出了需要完成的元素的索引。我想将这些索引与路径的位置、命令名称或 pyparsing 返回的解析结果的参数进行匹配。

如何获取不同令牌的位置并继续使用 setResultsName() 来命名我的令牌？

from pyparsing import Optional, Regex, Word
from pyparsing import alphanums

class Shell(object):
    def __init__(self):
        # Simplified grammar of the command line
        # path command parameters
        command = Word(alphanums + '_').setResultsName('command')
        bookmark = Regex('@([A-Za-z0-9:_.]|-)+')
        pathstd = Regex('([A-Za-z0-9:_.]|-)*' + '/' + '([A-Za-z0-9:_./]|-)*') \
                | '..' | '.'
        path = (bookmark | pathstd | '*')('path')
        parser = Optional(path) + Optional(command) # + Optional(parameters)
        self.parser = parser

    def parse_cmdline(self, line):
        parse_results = self.parser.parseString(line)
        path = parse_results.path
        command = parse_results.command
        return (parse_results, path, command)

    def complete(self):
        """Completion method called by readline"""
        cmdline = readline.get_line_buffer()
        (result_trees, path, command) = self.parse_cmdline(cmdline)

        beg = readline.get_begidx()
        end = readline.get_endidx()
        prefix = cmdline[beg:end]
        # if beg == path.location:
        #     completion = self.get_path_completion()
        # elif beg == command.location:
        #     completion = self.get_command_completion()
        # elif beg in parameters.location:
        #     completion = self.get_parameter_completion()
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1 回答 1

4

尝试在命令和路径表达式中添加定位器：

locator = Empty().setParseAction(lambda s,l,t: l)
def locatedExpr(expr):
    return Group(locator("location") + expr("value"))

class Shell(object):
    def __init__(self):
        # Simplified grammar of the command line
        # path command parameters
        #command = Word(alphanums + '_').setResultsName('command')
        command = locatedExpr(Word(alphanums + '_'))('command')
        bookmark = Regex('@([A-Za-z0-9:_.]|-)+')
        pathstd = Regex('([A-Za-z0-9:_.]|-)*' + '/' + '([A-Za-z0-9:_./]|-)*') \
                | '..' | '.'
        #path = (bookmark | pathstd | '*')('path')
        path = locatedExpr(bookmark | pathstd | '*')('path')
        parser = Optional(path) + Optional(command) # + Optional(parameters)
        self.parser = parser

现在您应该能够访问path.location并path.value获取路径的位置和匹配的文本，命令也是如此。

于 2013-09-10T00:34:38.113 回答