stri_replace: Replace Pattern Occurrences
Description
These functions replace, with the given replacement string, every/first/last substring of the input that matches the specified pattern.
Usage
stri_replace_all(str, replacement, ..., regex, fixed, coll, charclass)
stri_replace_first(str, replacement, ..., regex, fixed, coll, charclass)
stri_replace_last(str, replacement, ..., regex, fixed, coll, charclass)
stri_replace(
str,
replacement,
...,
regex,
fixed,
coll,
charclass,
mode = c("first", "all", "last")
)
stri_replace_all_charclass(
str,
pattern,
replacement,
merge = FALSE,
vectorize_all = TRUE,
vectorise_all = vectorize_all
)
stri_replace_first_charclass(str, pattern, replacement)
stri_replace_last_charclass(str, pattern, replacement)
stri_replace_all_coll(
str,
pattern,
replacement,
vectorize_all = TRUE,
vectorise_all = vectorize_all,
...,
opts_collator = NULL
)
stri_replace_first_coll(str, pattern, replacement, ..., opts_collator = NULL)
stri_replace_last_coll(str, pattern, replacement, ..., opts_collator = NULL)
stri_replace_all_fixed(
str,
pattern,
replacement,
vectorize_all = TRUE,
vectorise_all = vectorize_all,
...,
opts_fixed = NULL
)
stri_replace_first_fixed(str, pattern, replacement, ..., opts_fixed = NULL)
stri_replace_last_fixed(str, pattern, replacement, ..., opts_fixed = NULL)
stri_replace_all_regex(
str,
pattern,
replacement,
vectorize_all = TRUE,
vectorise_all = vectorize_all,
...,
opts_regex = NULL
)
stri_replace_first_regex(str, pattern, replacement, ..., opts_regex = NULL)
stri_replace_last_regex(str, pattern, replacement, ..., opts_regex = NULL)
Arguments
|
character vector; strings to search in |
|
character vector with replacements for matched patterns |
|
supplementary arguments passed to the underlying functions, including additional settings for |
|
single string; one of: |
|
character vector; search patterns; for more details refer to stringi-search |
|
single logical value; should consecutive matches be merged into one string; |
|
single logical value; should each occurrence of a pattern in every string be replaced by a corresponding replacement string?; |
|
alias of |
|
a named list used to tune up the search engine’s settings; see |
Details
By default, all the functions are vectorized over str, pattern, replacement (with recycling of the elements in the shorter vector if necessary). Input that is not part of any match is left unchanged; each match is replaced in the result by the replacement string.
However, for stri_replace_all*, if vectorize_all is FALSE, then each substring matching any of the supplied patterns is replaced by a corresponding replacement string. In such a case, the vectorization is over str, and - independently - over pattern and replacement. In other words, this is equivalent to something like for (i in 1:npatterns) str <- stri_replace_all(str, pattern[i], replacement[i]. Note that you must set length(pattern) >= length(replacement).
In case of stri_replace_*_regex, the replacement string may contain references to capture groups (in round parentheses). References are of the form $n, where n is the number of the capture group ($1 denotes the first group). For the literal $, escape it with a backslash. Moreover, ${name} are used for named capture groups.
Note that stri_replace_last_regex searches from start to end, but skips overlapping matches, see the example below.
stri_replace, stri_replace_all, stri_replace_first, and stri_replace_last are convenience functions; they just call stri_replace_*_* variants, depending on the arguments used.
If you wish to remove white-spaces from the start or end of a string, see stri_trim.
Value
All the functions return a character vector.
See Also
The official online manual of stringi at https://stringi.gagolewski.com/
Gagolewski M., stringi: Fast and portable character string processing in R, Journal of Statistical Software 103(2), 2022, 1-59, doi:10.18637/jss.v103.i02
Other search_replace: about_search, stri_replace_rstr(), stri_trim_both()
Examples
stri_replace_all_charclass('aaaa', '[a]', 'b', merge=c(TRUE, FALSE))
## Warning in stri_replace_all_charclass("aaaa", "[a]", "b", merge = c(TRUE, :
## argument `merge` should be a single logical value; only the first element is
## used
## [1] "b"
stri_replace_all_charclass('a\nb\tc d', '\\p{WHITE_SPACE}', ' ')
## [1] "a b c d"
stri_replace_all_charclass('a\nb\tc d', '\\p{WHITE_SPACE}', ' ', merge=TRUE)
## [1] "a b c d"
s <- 'Lorem ipsum dolor sit amet, consectetur adipisicing elit.'
stri_replace_all_fixed(s, ' ', '#')
## [1] "Lorem#ipsum#dolor#sit#amet,#consectetur#adipisicing#elit."
stri_replace_all_fixed(s, 'o', '0')
## [1] "L0rem ipsum d0l0r sit amet, c0nsectetur adipisicing elit."
stri_replace_all_fixed(c('1', 'NULL', '3'), 'NULL', NA)
## [1] "1" NA "3"
stri_replace_all_regex(s, ' .*? ', '#')
## [1] "Lorem#dolor#amet,#adipisicing elit."
stri_replace_all_regex(s, '(el|s)it', '1234')
## [1] "Lorem ipsum dolor 1234 amet, consectetur adipisicing 1234."
stri_replace_all_regex('abaca', 'a', c('!', '*'))
## [1] "!b!c!" "*b*c*"
stri_replace_all_regex('123|456|789', '(\\p{N}).(\\p{N})', '$2-$1')
## [1] "3-1|6-4|9-7"
stri_replace_all_regex(c('stringi R', 'REXAMINE', '123'), '( R|R.)', ' r ')
## [1] "stringi r " " r XAMINE" "123"
# named capture groups are available since ICU 55
## Not run:
stri_replace_all_regex('words 123 and numbers 456',
'(?<numbers>[0-9]+)', '!${numbers}!')
## [1] "words !123! and numbers !456!"
## End(Not run)
# Compare the results:
stri_replace_all_fixed('The quick brown fox jumped over the lazy dog.',
c('quick', 'brown', 'fox'), c('slow', 'black', 'bear'), vectorize_all=TRUE)
## [1] "The slow brown fox jumped over the lazy dog."
## [2] "The quick black fox jumped over the lazy dog."
## [3] "The quick brown bear jumped over the lazy dog."
stri_replace_all_fixed('The quick brown fox jumped over the lazy dog.',
c('quick', 'brown', 'fox'), c('slow', 'black', 'bear'), vectorize_all=FALSE)
## [1] "The slow black bear jumped over the lazy dog."
# Compare the results:
stri_replace_all_fixed('The quicker brown fox jumped over the lazy dog.',
c('quick', 'brown', 'fox'), c('slow', 'black', 'bear'), vectorize_all=FALSE)
## [1] "The slower black bear jumped over the lazy dog."
stri_replace_all_regex('The quicker brown fox jumped over the lazy dog.',
'\\b'%s+%c('quick', 'brown', 'fox')%s+%'\\b', c('slow', 'black', 'bear'), vectorize_all=FALSE)
## [1] "The quicker black bear jumped over the lazy dog."
# Searching for the last occurrence:
# Note the difference - regex searches left to right, with no overlaps.
stri_replace_last_fixed("agAGA", "aga", "*", case_insensitive=TRUE)
## [1] "ag*"
stri_replace_last_regex("agAGA", "aga", "*", case_insensitive=TRUE)
## [1] "*GA"