R-迭代组合字符向量的连续元素，直到到达空字符串元素

Question

我有一个由长字符串（字母数字+特殊字符）组成的字符向量，如下面所述。需要

txt <- c(
     "Spicy jalapeno bacon ipsum dolor amet", 
     "tenderloin. pariatur quis", 
     "", 
     "consequat pancetta jerky", 
     "porchetta non chuck exercitation", 
     "laborum labore ball tip.", 
     "", 
     "", 
     "Duis swine turkey kielbasa. Strip ", 
     "steak ribeye laboris," 
     ) 

输出是

> txt 
[1] "Spicy jalapeno bacon ipsum dolor amet tenderloin. pariatur quis" 
[2] "consequat pancetta jerky porchetta non chuck exercitation laborum labore ball tip." 
[3] "Duis swine turkey kielbasa. Strip steak ribeye laboris," 

需要考虑的事项：
1.空字符串元件/ s的充当linebreakers。他们可以连续超过一个。
2.将两个元素连接在一起时，需要在两者之间添加空格。

Answer 1

其中一个方法可以做到这过多的：

library(dplyr) 
library(purrr) 

data_frame(txt=txt, grp=cumsum(txt=="")) %>% 
    group_by(grp) %>% 
    do(data_frame(joined=paste0(.$txt, collapse=" "))) %>% 
    mutate(joined=trimws(joined)) %>% 
    filter(joined != "") %>% 
    ungroup() %>% 
    select(joined) %>% 
    flatten_chr() 
## [1] "Spicy jalapeno bacon ipsum dolor amet tenderloin. pariatur quis"     
## [2] "consequat pancetta jerky porchetta non chuck exercitation laborum labore ball tip." 
## [3] "Duis swine turkey kielbasa. Strip steak ribeye laboris,"