str_interp() now renders lists consistently independent on the presence of additional placeholders (@amhrasmussen).
New str_starts() and str_ends() functions to detect patterns at the beginning or end of strings (@jonthegeek, #258).
str_subset(), str_detect(), and str_which() get negate argument, which is useful when you want the elements that do NOT match (#259, @yutannihilation).
New str_to_sentence() function to capitalize with sentence case (@jonthegeek, #202).
str_replace_all() with a named vector now respects modifier functions (#207)
str_trunc() is once again vectorised correctly (#203, @austin3dickey).
str_view() handles NA values more gracefully (#217). I’ve also tweaked the sizing policy so hopefully it should work better in notebooks, while preserving the existing behaviour in knit documents (#232).
Error : object ‘ignore.case’ is not exported by 'namespace:stringr'. This is because the long deprecated str_join(), ignore.case() and perl() have now been removed.str_glue() and str_glue_data() provide convenient wrappers around glue and glue_data() from the glue package (#157).
str_flatten() is a wrapper around stri_flatten() and clearly conveys flattening a character vector into a single string (#186).
str_remove() and str_remove_all() functions. These wrap str_replace() and str_replace_all() to remove patterns from strings. (@Shians, #178)
str_squish() removes spaces from both the left and right side of strings, and also converts multiple space (or space-like characters) to a single space within strings (@stephlocke, #197).
str_sub() gains omit_na argument for ignoring NA. Accordingly, str_replace() now ignores NAs and keeps the original strings. (@yutannihilation, #164)
str_trunc() now preserves NAs (@ClaytonJY, #162)
str_trunc() now throws an error when width is shorter than ellipsis (@ClaytonJY, #163).
Long deprecated str_join(), ignore.case() and perl() have now been removed.
str_match_all() now returns NA if an optional group doesn’t match (previously it returned ""). This is more consistent with str_match() and other match failures (#134).In str_replace(), replacement can now be a function that is called once for each match and whose return value is used to replace the match.
New str_which() mimics grep() (#129).
A new vignette (vignette("regular-expressions")) describes the details of the regular expressions supported by stringr. The main vignette (vignette("stringr")) has been updated to give a high-level overview of the package.
str_order() and str_sort() gain explicit numeric argument for sorting mixed numbers and strings.
str_replace_all() now throws an error if replacement is not a character vector. If replacement is NA_character_ it replaces the complete string with replaces with NA (#124).
All functions that take a locale (e.g. str_to_lower() and str_sort()) default to “en” (English) to ensure that the default is consistent across platforms.
Add sample datasets: fruit, words and sentences.
fixed(), regex(), and coll() now throw an error if you use them with anything other than a plain string (#60). I’ve clarified that the replacement for perl() is regex() not regexp() (#61). boundary() has improved defaults when splitting on non-word boundaries (#58, @lmullen).
str_detect() now can detect boundaries (by checking for a str_count() > 0) (#120). str_subset() works similarly.
str_extract() and str_extract_all() now work with boundary(). This is particularly useful if you want to extract logical constructs like words or sentences. str_extract_all() respects the simplify argument when used with fixed() matches.
str_subset() now respects custom options for fixed() patterns (#79, @gagolews).
str_replace() and str_replace_all() now behave correctly when a replacement string contains $s, \\\\1, etc. (#83, #99).
str_split() gains a simplify argument to match str_extract_all() etc.
str_view() and str_view_all() create HTML widgets that display regular expression matches (#96).
word() returns NA for indexes greater than number of words (#112).
stringr is now powered by stringi instead of base R regular expressions. This improves unicode and support, and makes most operations considerably faster. If you find stringr inadequate for your string processing needs, I highly recommend looking at stringi in more detail.
stringr gains a vignette, currently a straight forward update of the article that appeared in the R Journal.
str_c() now returns a zero length vector if any of its inputs are zero length vectors. This is consistent with all other functions, and standard R recycling rules. Similarly, using str_c("x", NA) now yields NA. If you want "xNA", use str_replace_na() on the inputs.
str_replace_all() gains a convenient syntax for applying multiple pairs of pattern and replacement to the same vector:
str_match() now returns NA if an optional group doesn’t match (previously it returned ""). This is more consistent with str_extract() and other match failures.
New str_subset() keeps values that match a pattern. It’s a convenient wrapper for x[str_detect(x)] (#21, @jiho).
New str_order() and str_sort() allow you to sort and order strings in a specified locale.
New str_conv() to convert strings from specified encoding to UTF-8.
New modifier boundary() allows you to count, locate and split by character, word, line and sentence boundaries.
The documentation got a lot of love, and very similar functions ( e.g. first and all variants) are now documented together. This should hopefully make it easier to locate the function you need.
ignore.case(x) has been deprecated in favour of fixed|regex|coll(x, ignore.case = TRUE), perl(x) has been deprecated in favour of regex(x).
str_join() is deprecated, please use str_c() instead.
fixed path in str_wrap example so works for more R installations.
remove dependency on plyr
Zero input to str_split_fixed returns 0 row matrix with n columns
Export str_join
new modifier perl that switches to Perl regular expressions
str_match now uses new base function regmatches to extract matches - this should hopefully be faster than my previous pure R algorithm
new str_wrap function which gives strwrap output in a more convenient format
new word function extract words from a string given user defined separator (thanks to suggestion by David Cooper)
str_locate now returns consistent type when matching empty string (thanks to Stavros Macrakis)
new str_count counts number of matches in a string.
str_pad and str_trim receive performance tweaks - for large vectors this should give at least a two order of magnitude speed up
str_length returns NA for invalid multibyte strings
fix small bug in internal recyclable function