如果它总是字符串的最后一部分，你可以匹配最后一个双引号后面的点：

(.*?) is the (father|mother) of "(.*?)"\.

字符串
举例来说：

ex02ChildrenInverse <- function(sentence) {
  
  matches <- regmatches(
    sentence,
    regexec('(.*?) is the (father|mother) of "(.*?)"\\.', sentence))[[1]]
    
  parent <- matches[[2]]
  male   <- matches[[3]] == "father"
  child  <- matches[[4]]
  
  return(list(parent = parent, male = male, child = child))
}
ex02ChildrenInverse('Gudrun is the mother of "Rosamunde ("Rosi")".')

型
输出

$parent
[1] "Gudrun"

$male
[1] FALSE

$child
[1] "Rosamunde (\"Rosi\")"

型
参见R demo和regex demo

一种新的代码方法是使用gsub和grepl来获取你想要的相关信息，而不是尝试使用regmatches来完成所有这些：

freshCode <- function(sentence) {
  parent <- gsub("(\\w+).*", "\\1", sentence)
  male <- grepl("father", sentence)
  child <- gsub("\\.", "", substring(sentence, regexpr('"', sentence) + 1))
  list(parent = parent, male = male, child = child)
}

freshCode('Gudrun is the mother of "Rosamunde ("Rosi")".')

# $parent
# [1] "Gudrun"
# 
# $male
# [1] FALSE
# 
# $child
# [1] "Rosamunde (\"Rosi\")\""

# Note the "\" in the above are not truly "visible": 
# > cat(freshCode('Gudrun is the mother of "Rosamunde ("Rosi")".')[[3]])
# Rosamunde ("Rosi")"

字符串
或者稍微修改一下你现有的代码：

ex02ChildrenInverse <- function(sentence) {
  matches <- regmatches(
    sentence,
    regexec('^(.*?) is the (father|mother) of "(.*?)"', sentence))[[1]]
  parent <- matches[[2]]
  male <- matches[[3]] == "father"
  child <- gsub("\\.", "", substring(sentence, regexpr('"', sentence) + 1))
  
  return(list(parent = parent, male = male, child = child))
}

型
它将返回与上面相同的输出。