convert utf8 code point strings like to utf8

Answer 1

The previous answer should work when the code point is presented with exactly four digits. Here is a modified version that should work for any number of digits between 1 and 8.

library(stringi)
library(magrittr)

"foo<U+0161>bar and cra<U+017E>y, Phoenician letter alf <U+10900>" %>% 
  stri_replace_all_regex("<U\\+([[:alnum:]]{4})>", "\\\\u$1") %>% 
  stri_replace_all_regex("<U\\+([[:alnum:]]{5})>", "\\\\U000$1") %>% 
  stri_replace_all_regex("<U\\+([[:alnum:]]{6})>", "\\\\U00$1") %>% 
  stri_replace_all_regex("<U\\+([[:alnum:]]{7})>", "\\\\U0$1") %>% 
  stri_replace_all_regex("<U\\+([[:alnum:]]{8})>", "\\\\U$1") %>% 
  stri_replace_all_regex("<U\\+([[:alnum:]]{1})>", "\\\\u000$1") %>% 
  stri_replace_all_regex("<U\\+([[:alnum:]]{2})>", "\\\\u00$1") %>% 
  stri_replace_all_regex("<U\\+([[:alnum:]]{3})>", "\\\\u0$1") %>% 
  stri_unescape_unicode() %>% 
  stri_enc_toutf8()
## [1] "foošbar and cražy, Phoenician letter alf                                                                     

                                                        
            

Answer 2

Perhaps:

library(stringi)
library(magrittr)

"foo<U+0161>bar and cra<U+017E>y" %>% 
  stri_replace_all_regex("<U\\+([[:alnum:]]+)>", "\\\\u$1") %>% 
  stri_unescape_unicode() %>% 
  stri_enc_toutf8()
## [1] "foošbar and cražy"

may work (I don't need the last conversion on macOS but you may on Windows).