使用嵌套括号解析字符串

Question

要解析的字符串(不含空格):

 "instrumentalist  (  bass  (upright  , fretless , 5-string ) ,  guitar  ( electric , acoustic ) ,  trumpet  ),  teacher  ,  songwriter,    producer"

我需要在Ruby中获得这个结构

["instrumentalist",[["bass",["upright","fretless","5-string"]],["guitar",["electric","acoustic"]],["trumpet"]],["teacher"],["songwriter"],["producer"]]

由于嵌套(,)并, String#partition不能帮助我.我真的不知道是否有一个花哨的RegEx可以提取这种类型的字符串.或者我必须使用词法分析器？

Answer 1

对于这类问题,正则表达式本身并不是正确的事情,即使基本过程很简单:遍历字符串寻找逗号或括号.当您找到逗号时,将先前读取的字符添加到当前嵌套中.当你找到一个开放式支架时,你的嵌套级别会上升1,当你发现一个小括号减去它时.

StringScanner是为这类东西而设计的,因为它允许我们在保持某些状态时遍历字符串,在这种情况下,是一个镜像你的开始和结束括号的堆栈.这样的事情对我有用

require 'strscan'

def parse input
  scanner = StringScanner.new input
  stack = [[]]
  while string = scanner.scan(/[^(),]+/)
    case scanner.scan /[(),]+/
    when '('
      new_nesting = [string, []]
      stack.last << new_nesting
      stack << new_nesting[1]
    when ')'
      scanner.scan(/,/)
      stack.last << string
      stack.pop
    else
      stack.last << string
    end
  end
  stack.last
end