python - 从 Python 移植到 Ruby 时出现问题

Question

我有一个简洁的 python 小脚本，我想将其移植到 Ruby，我认为它凸显了我对 Ruby 的不懂。我收到错误消息，指出存在意外的 END 语句，但我不明白为什么会这样。也许有一个关键字需要 END，或者我忘记了不需要 END 的关键字。以下是导致违规行的所有代码。违规行已被注释。

begin
    require base64
    require base32
rescue LoadError
    puts "etext requires base32. use 'gem install --remote base32' and try again"
end

# Get a string from a text file from disk
filename = ARGV.first
textFile = File.open(filename)
text = textFile.read()

mailType = "text only" # set the default mailType

#cut the email up by sections
textList1 = text.split(/\n\n/)
header = textList1[0]

if header.match (/MIME-Version/)
    mailType = "MIME"
end

#If mail has no attachments, parse as text-only. This is the class that does this
class TextOnlyMailParser

    def initialize(textList)
        a = 1
        body = ""
        header = textList[0]
        @parsedEmail = Email.new(header)
        while a < textList.count
            body += ('\n' + textList[a] + '\n')
            a += 1
            end
        @parsedEmail.body = body
    end
end

def separate(text,boundary = nil)
    # returns list of strings and lists containing all of the parts of the email
    if !boundary #look in the email for "boundary= X"
        text.scan(/(?<=boundary=).*/) do |bound|
            textList = recursiveSplit(text,bound)
            end
        return textList
    end
    if boundary 
        textList = recursiveSplit(text,boundary)
    end
end


def recursiveSplit(chunk,boundary)
    if chunk.is_a? String
        searchString = "--" + boundary
        ar = cunk.split(searchString)
        return ar
    elsif chunk.is_a? Array
        chunk do |bit|
            recursiveSplit(bit,boundary);
        end
    end
end

class MIMEParser
    def initialize(textList)
        @textList = textList
        @nestedItems = []
        newItem = NestItem.new(self)
        newItem.value = @textList[0]
        newItem.contentType = "Header"
        @nestedItems.push(newItem)
        #setup parsed email
        @parsedEmail = Email.new(newItem.value)
        self._constructNest
    end

        def checkForContentSpecial(item)
        match = item.value.match (/Content-Disposition: attachment/)
        if match
            filename = item.value.match (/(?<=filename=").+(?=")/)
            encoding = item.value.match (/(?<=Content-Transfer-Encoding: ).+/)
            data = item.value.match (/(?<=\n\n).*(?=(\n--)|(--))/m)
            dataGroup = data.split(/\n/)
            dataString = ''
            i = 0
            while i < dataGroup.count
                dataString += dataGroup[i]
                i ++
            end #<-----THIS IS THE OFFENDING LINE
            @parsedEmail.attachments.push(Attachment.new(filename,encoding,dataString))
        end

Answer 1

您的问题是 i++ 行，Ruby 没有后置或前置递增/递减运算符，并且该行无法解析。我个人无法解释为什么 i++ 在 IRB 中求值，但 i++ 不执行任何操作。

而是用 += 1 替换您的 ++ 运算符，使最后一个 while :

while i < dataGroup.count
  dataString += dataGroup[i]
  i += 1
end

但也要考虑一下 ruby​​ 方式，如果您只是将其添加到字符串中，为什么不执行 dataString = dataGroup.join 而不是使用 while 构造进行循环？