Merge rows in tibble

I'd like to list all Functions my package in a table.

So far I extracted all functions and title from the packages help docs

library(magrittr)
package_info <- library(help = magrittr)$info[[2]]
package_info_tbl <- package_info %>% 
  stringr::str_split(pattern = "\\s+", n = 2, simplify = T) %>%
  tibble::as_tibble(.name_repair = "minimal")
colnames(package_info_tbl) <- c("Function", "Title")

package_info_tbl
#> # A tibble: 13 x 2
#>    Function     Title                                          
#>    <chr>        <chr>                                          
#>  1 "%$%"        magrittr exposition pipe-operator              
#>  2 "%<>%"       magrittr compound assignment pipe-operator     
#>  3 "%>%"        magrittr forward-pipe operator                 
#>  4 "%T>%"       magrittr tee operator                          
#>  5 "[[.fseq"    Extract function(s) from a functional sequence.
#>  6 "debug_fseq" Debugging function for functional sequences.   
#>  7 "debug_pipe" Debugging function for magrittr pipelines.     
#>  8 "extract"    Aliases                                        
#>  9 "freduce"    Apply a list of functions sequentially         
#> 10 "functions"  Extract the function list from a functional    
#> 11 ""           sequence.                                      
#> 12 "magrittr"   magrittr - Ceci n'est pas un pipe              
#> 13 "print.fseq" Print method for functional sequence.

^{Created on 2020-03-29 by the reprex package (v0.3.0)}

I found that some rows are seperated and result in 2 or more rows if the title is long. How to merge these rows?

Solution

We can replace blank with NA values, use fill to replace NA with previous value in Function column, group_by Function and create one concatenated string for each Function.

library(dplyr)

package_info_tbl %>%
  na_if('') %>%
  tidyr::fill(Function)  %>%
  group_by(Function) %>%
  summarise(Title = paste(Title, collapse = " "))


# A tibble: 12 x 2
#   Function   Title                                                
#   <chr>      <chr>                                                
# 1 [[.fseq    Extract function(s) from a functional sequence.      
# 2 %<>%       magrittr compound assignment pipe-operator           
# 3 %>%        magrittr forward-pipe operator                       
# 4 %$%        magrittr exposition pipe-operator                    
# 5 %T>%       magrittr tee operator                                
# 6 debug_fseq Debugging function for functional sequences.         
# 7 debug_pipe Debugging function for magrittr pipelines.           
# 8 extract    Aliases                                              
# 9 freduce    Apply a list of functions sequentially               
#10 functions  Extract the function list from a functional sequence.
#11 magrittr   magrittr - Ceci n'est pas un pipe                    
#12 print.fseq Print method for functional sequence.