# stringi package NEWS and CHANGELOG

-------------------------------------------------------------------------------

## 1.4.6 (2020-02-17) **devel*

* [NEW FEATURE] #369: `stri_c()` now returns an empty string
when input is empty and `collapse` is set.

* [BUGFIX] #370: fixed an issue in `stri_prepare_arg_POSIXct()`
reported by rchk.

* [BUGFIX] #372: documented arguments not in `\usage` in
documentation object `stri_datetime_format`: `...`

-----------------------------------------------------------------------------

## 1.4.5 (2020-01-11) **CRAN*

* [BUGFIX] #366: fix for #363 required ICU >= 55 .

-----------------------------------------------------------------------------

## 1.4.4 (2020-01-06) **CRAN**

* [BUGFIX] #348: Avoid copying 0 bytes to a nil-buffer in `stri_sub_all()`.

* [BUGFIX] #362: Removed `configure` variable `CXXCPP` as it is now deprecated.

* [BUGFIX] #318: PROTECTing objects from gcing as reported by `rchk`.

* [BUGFIX] #344, #364: Removed compiler warnings in icu61/common/cstring.h.

* [BUGFIX] #363: Status of `RegexMatcher` is now checked after its use.

-------------------------------------------------------------------------------

## 1.4.3 (2019-03-12) **CRAN**

* [NEW FEATURE] #30: New function `stri_sub_all()` - a version of
  `stri_sub()` accepting list `from`/`to`/`length` arguments for extracting
  multiple substrings from each string in a character vector.

* [NEW FEATURE] #30: New function `stri_sub_all<-()` (and its `%<%`-friendly
  version, `stri_sub_replace_all()`) - for replacing multiple substrings
  with corresponding replacement strings.

* [NEW FEATURE] In `stri_sub_replace()`, `value` parameter
  has a new alias, `replacement`.

* [NEW FEATURE] New convenience functions based on `stri_remove_empty()`:
  `stri_omit_empty_na()`, `stri_remove_empty_na()`, `stri_omit_empty()`,
  and also `stri_remove_na()`, `stri_omit_na()`.

* [BUGFIX] #343: `stri_trans_char()` did not yield correct results
  for overlapping pattern and replacement strings.

* [WARNFIX] #205: `configure.ac` is now included in the source bundle.

-------------------------------------------------------------------------------

## 1.3.1 (2019-02-10) **CRAN**

* [BACKWARD INCOMPATIBILITY] #335: A fix to #314 prevented (by design) the use
  of the system ICU if the library had been compiled with `U_CHARSET_IS_UTF8=1`.
  However, this is the default setting in `libicu`>=61. From now on, in such
  cases the system ICU is used more eagerly, but `stri_enc_set()` issues
  a warning stating that the default (UTF-8) encoding cannot be changed.

* [NEW FEATURE] #232: All `stri_detect_*` functions now have the `max_count`
  argument that allows for, e.g., stopping at the first pattern occurrence.

* [NEW FEATURE] #338: `stri_sub_replace()` is now an alias for `stri_sub<-()`
  which makes it much more easily pipable (@yutannihilation, @BastienFR).

* [NEW FEATURE] #334: Added missing `icudt61b.dat` to support big-endian
  platforms (thanks to Dimitri John Ledkov @xnox).

* [BUGFIX] #296: Out-of-the box build used to fail on CentOS 6, upgraded
  `./configure` to `--disable-cxx11` more eagerly at an early stage.

* [BUGFIX] #341: Fixed possible buffer overflows when calling `strncpy()`
  from within ICU 61.

* [BUGFIX] #325: Made `./configure` more portable so that it works
  under `/bin/dash` now.

* [BUGFIX] #319: Fixed overflow in `stri_rand_shuffle()`.

* [BUGFIX] #337: Empty search patters in search functions (e.g.,
  `stri_split_regex()` and `stri_count_fixed()`) used to raise
  too many warnings on empty search patters.

-------------------------------------------------------------------------------

## 1.2.4 (2018-07-20) **CRAN**

* [BUGFIX] #314: Testing `U_CHARSET_IS_UTF8` in `./configure` when
  using `pkg-build`.

* ~~[BUILD TIME] #317: Included `icudt61l.zip` in the source bundle to solve
  the frequent `icudt download failed` error (also on CRAN's `windows-release`
  and `windows-oldrel`).~~ (reverted in version 1.3.1, the `winbuilder`
  errors were caused by a build chain bug).

-------------------------------------------------------------------------------

## 1.2.3 (2018-05-16) **CRAN**

* [BUGFIX] #296: Fixed the behavior of the `./configure` script on CentOS 6.

* [BUGFIX] Fixed broken Windows build by updating the `icudt` mirror list.

-------------------------------------------------------------------------------

## 1.2.2 (2018-05-01) **CRAN**

* [GENERAL] #193: stringi is now bundled with ICU4C 61.1,
  which is used on most Windows and OS X builds as well as on *nix systems
  not equipped with ICU. However, if the C++11 support is disabled,
  stringi will be built against ICU4C 55.1. The update to ICU brings
  Unicode 10.0 support, including new emoji characters.

* [BUGFIX] #288: `stri_match()` did not return the correct number of columns
  when input was empty.

* [NEW FEATURE] #188: `stri_enc_detect()` now returns a list of data frames.

* [NEW FEATURE] #289: `stri_flatten()` how has `na_empty` and `omit_empty`
  arguments.

* [NEW FEATURE] New functions: `stri_remove_empty()`, `stri_na2empty()`.

* [NEW FEATURE] #285: Coercion from a non-trivial list (one that consists
  of atomic vectors, each of length 1) to an atomic vector now issues a warning.

* [WARN] Removed `-Wparentheses` warnings in `icu55/common/cstring.h:38:63`
  and `icu55/i18n/windtfmt.cpp` in the ICU4C 55.1 bundle.

-------------------------------------------------------------------------------

## 1.1.7 (2018-03-06) **CRAN**

* [BUGFIX] Fixed ICU4C 55.1 generating some *significant warnings*
  (`icu55/i18n/winnmfmt.cpp`) and *suppressing important diagnostics*
  (`src/icu55/i18n/decNumber.c`).

-------------------------------------------------------------------------------

## 1.1.6 (2017-11-10) **CRAN**

* [WINDOWS SPECIFIC] #270: Strings marked with `latin1` encoding
  are now converted internally to UTF-8 using the WINDOWS-1252 codec.
  This fixes problems with - among others - displaying the Euro sign.

* [NEW FEATURE] #263: Added support for custom rule-based break iteration,
  see `?stri_opts_brkiter`.

* [NEW FEATURE] #267: `omit_na=TRUE` in `stri_sub<-()` now ignores missing
  values in any of the arguments provided.

* [BUGFIX] Fixed unPROTECTed variable names and stack imbalances
  as reported by `rchk`.

-------------------------------------------------------------------------------

## 1.1.5 (2017-04-07) **CRAN**

* [GENERAL] stringi now requires ICU4C >= 52.

* [BUGFIX] Fixed errors pointed out by `clang-UBSAN` in `stri_brkiter.h`.

-------------------------------------------------------------------------------

## 1.1.4 (2017-04-06) **devel**

* [GENERAL] stringi now requires R >= 2.14.

* [BUILD TIME] #238, #220: Now trying *standard* ICU4C build flags if a call
  to `pkg-config` fails.

* [BUILD TIME] #258: Use `CXX11` instead of `CXX1X` on R >= 3.4.

* [BUILD TIME, BUGFIX] #254: `dir.exists()` is R >= 3.2.

-------------------------------------------------------------------------------

## 1.1.3 (2017-03-21) **CRAN**

* [REMOVE DEPRECATED] `stri_install_check()` and `stri_install_icudt()`
  marked as deprecated in stringi 0.5-5 are no longer being exported.

* [BUGFIX] #227: Incorrect behavior of `stri_sub()` and `stri_sub<-()`
  if the empty string was the result.

* [BUILD TIME] #231: The `./configure` (*NIX only) script now reads the
  following environment variables: `STRINGI_CFLAGS`, `STRINGI_CPPFLAGS`,
  `STRINGI_CXXFLAGS`, `STRINGI_LDFLAGS`, `STRINGI_LIBS`,
  `STRINGI_DISABLE_CXX11`, `STRINGI_DISABLE_ICU_BUNDLE`,
  `STRINGI_DISABLE_PKG_CONFIG`, `PKG_CONFIG`,
  see `INSTALL` for more information.

* [BUILD TIME] #253: Call to `R_useDynamicSymbols()` added.

* [BUILD TIME] #230: `icudt` is now being downloaded by
  `./configure` (*NIX only) *before* building.

* [BUILD TIME] #242: `_COUNT/_LIMIT` enum constants have been deprecated
  as of ICU 58.2, stringi code has been upgraded accordingly.

-------------------------------------------------------------------------------

## 1.1.2 (2016-09-30) **CRAN**

* [BUGFIX] `round()`, `snprintf()` is not C++98.

-------------------------------------------------------------------------------

## 1.1.1 (2016-05-25) **CRAN**

* [BUGFIX] #214: Allow a regex pattern like `.*`  to match an empty string.

* [BUGFIX] #210: `stri_replace_all_fixed(c("1", "NULL"), "NULL", NA)`
  now results in `c("1", NA)`.

* [NEW FEATURE] #199: `stri_sub<-()` now allows for ignoring `NA` locations
  (a new `omit_na` argument added).

* [NEW FEATURE] #207: `stri_sub<-()` now allows for substring insertions
  (via `length=0`).

* [NEW FUNCTION] #124: `stri_subset<-()` functions added.

* [NEW FEATURE] #216: `stri_detect()`, `stri_subset()`, `stri_subset<-()`
  now all have the `negate` argument.

* [NEW FUNCTION] #175: `stri_join_list()` concatenates all strings
  in a list of character vectors. Useful in conjunction with, e.g.,
  `stri_extract_all_regex()`, `stri_extract_all_words()`, etc.

-------------------------------------------------------------------------------

## 1.0-1 (2015-10-22) **CRAN**

* [GENERAL] #88: C API is now available for use in, e.g., Rcpp packages, see
  https://github.com/gagolews/ExampleRcppStringi for an example.

* [BUGFIX] #183: Floating point exception raised in `stri_sub()` and
  `stri_sub<-()` when `to` or `length` was a zero-length numeric vector.

* [BUGFIX] #180: `stri_c()` warned incorrectly (recycling rule) when using more
  than two elements.

-------------------------------------------------------------------------------

## 0.5-5 (2015-06-28) **CRAN**

* [BACKWARD INCOMPATIBILITY] `stri_install_check()` and `stri_install_icudt()`
  are now deprecated. From now on they are supposed to be used only
  by the stringi installer.

* [BUGFIX] #176: A patch for `sys/feature_tests.h` no longer included
  (the original file was copyrighted by Sun Microsystems); fixed the *Compiler
  or options invalid for pre-UNIX 03 X/Open applications and pre-2001 POSIX
  applications* error by forcing (conditionally) `_XPG6` conformance.

* [BUGFIX] #174: `stri_paste()` did not generate any warning when
  the recycling rule is violated and `sep==""`.

* [BUGFIX] #170: `icu::setDataDirectory` is no longer called if our ICU
  source bundle is not used (this used to cause build problems on openSUSE).

* [BUILD TIME] #169: `./configure` now tries to switch to the *standard*
  C++ compiler if a C++11 one is not configured correctly.

* [BUILD TIME] `configure.win` (`Biarch: TRUE`) now mimics `autoconf`'s
  `AC_SUBST` and `AC_CONFIG_FILES` so that the build process is now
  more similar across different platforms.

* [NEW FEATURE] `stri_info()` now also gives information about which version
  of ICU4C is in use (system or bundle).

-------------------------------------------------------------------------------

## 0.5-2 (2015-06-21) **CRAN**

* [BACKWARD INCOMPATIBILITY] The second argument to `stri_pad_*()` has
  been renamed `width`.

* [GENERAL] #69: stringi is now bundled with ICU4C 55.1.

* [NEW FUNCTIONS] `stri_extract_*_boundaries()` extract text between text
  boundaries.

* [NEW FUNCTION] #46: `stri_trans_char()` is a stringi-flavoured
  `chartr()` equivalent.

* [NEW FUNCTION] #8: `stri_width()` approximates the *width* of a string
  in a more Unicode-ish fashion than `nchar(..., "width")`

* [NEW FEATURE] #149: `stri_pad()` and `stri_wrap()` is now (by default)
  based on code point widths instead of the number of code points.
  Moreover, the default behavior of `stri_wrap()` is now such that it
  does not get rid of non-breaking, zero width, etc., spaces.

* [NEW FEATURE] #133: `stri_wrap()` silently allows for `width <= 0`
  (for compatibility with `strwrap()`).

* [NEW FEATURE] #139: `stri_wrap()` gained a new argument: `whitespace_only`.

* [NEW FUNCTIONS] #137: Date-time formatting/parsing:

  * `stri_timezone_list()` - lists all known time zone identifiers;
  * `stri_timezone_set()`, `stri_timezone_get()` - manage the current
    default time zone;
  * `stri_timezone_info()` - basic information on a given time zone;
  * `stri_datetime_symbols()` - gives localizable date-time formatting data;
  * `stri_datetime_fstr()` - converts a `strptime`-like format string
         to an ICU date/time format string;
  * `stri_datetime_format()` - converts date/time to string;
  * `stri_datetime_parse()` - converts string to date/time object;
  * `stri_datetime_create()` - constructs date-time objects
         from numeric representations;
  * `stri_datetime_now()` - returns current date-time;
  * `stri_datetime_fields()` - returns date-time fields' values;
  * `stri_datetime_add()` - adds specific number of date-time units
         to a date-time object.

* [GENERAL] #144: Performance improvements in handling ASCII strings
  (these affect `stri_sub()`, `stri_locate()` and other string index-based
  operations)

* [GENERAL] #143: Searching for short fixed patterns (`stri_*_fixed()`) now
  relies on the current `libC`'s implementation of `strchr()` and `strstr()`.
  This is very fast, e.g., on `glibc` using the `SSE2/3/4` instruction set.

* [BUILD TIME] #141: A local copy of `icudt*.zip` may be used on package
  install; see the `INSTALL` file for more information.

* [BUILD TIME] #165: The `./configure` option `--disable-icu-bundle`
  forces the use of system ICU when building the package.

* [BUGFIX] Locale specifiers are now normalized in a more intelligent way:
  e.g., `@calendar=gregorian` expands to `DEFAULT_LOCALE@calendar=gregorian`.

* [BUGFIX] #134: `stri_extract_all_words()` did not accept `simplify=NA`.

* [BUGFIX] #132: Incorrect behavior in `stri_locate_regex()` for matches
  of zero lengths.

* [BUGFIX] stringr/#73: `stri_wrap()` returned `CHARSXP` instead of `STRSXP`
  on empty string input with `simplify=FALSE` argument.

* [BUGFIX] #164: Using `libicu-dev` failed on Ubuntu
  (`LIBS` shall be passed after `LDFLAGS` and the list of `.o` files).

* [BUGFIX] #168: Build now fails if `icudt` is not available.

* [BUGFIX] #135: C++11 is now used by default (see the `INSTALL` file,
  however) to build stringi from sources. This is because ICU4C uses the
  `long long` type which is not part of the C++98 standard.

* [BUGFIX] #154: Dates and other objects with a custom class attribute
  were not coerced to the character type correctly.

* [BUGFIX] Force ICU `u_init()` call on stringi dynlib load.

* [BUGFIX] #157: Many overfull hboxes in the package PDF manual has been
  corrected.

-------------------------------------------------------------------------------

## 0.4-1 (2014-12-11) **CRAN**

* [IMPORTANT CHANGE] `n_max` argument in `stri_split_*()` has been renamed `n`.

* [IMPORTANT CHANGE] `simplify=FALSE` in `stri_extract_all_*()` and
  `stri_split_*()` now calls `stri_list2matrix()` with `fill=""`.
  `fill=NA_character_` may be obtained by using `simplify=NA`.

* [IMPORTANT CHANGE, NEW FUNCTIONS] #120: `stri_extract_words()` has been
  renamed `stri_extract_all_words()` and `stri_locate_boundaries()` -
  `stri_locate_all_boundaries()` as well as `stri_locate_words()` -
  `stri_locate_all_words()`. New functions are now available:
  `stri_locate_first_boundaries()`, `stri_locate_last_boundaries()`,
  `stri_locate_first_words()`, `stri_locate_last_words()`,
  `stri_extract_first_words()`, `stri_extract_last_words()`.

* [IMPORTANT CHANGE] #111: `opts_regex`, `opts_collator`, `opts_fixed`, and
  `opts_brkiter` can now be supplied individually via `...`.
  In other words, you may now simply call, e.g.,
  `stri_detect_regex(str, pattern, case_insensitive=TRUE)` instead of
  `stri_detect_regex(str, pattern,
    opts_regex=stri_opts_regex(case_insensitive=TRUE))`.

* [NEW FEATURE] #110: Fixed pattern search engine's settings can
  now be supplied via `opts_fixed` argument in `stri_*_fixed()`,
  see `stri_opts_fixed()`. A simple (not suitable for natural language
  processing) yet very fast `case_insensitive` pattern matching can be
  performed now. `stri_extract_*_fixed()` is again available.

* [NEW FEATURE] #23: `stri_extract_all_fixed()`, `stri_count()`, and
  `stri_locate_all_fixed()` may now also look for overlapping pattern
  matches, see `?stri_opts_fixed`.

* [NEW FEATURE] #129: `stri_match_*_regex()` gained a `cg_missing` argument.

* [NEW FEATURE] #117: `stri_extract_all_*()`, `stri_locate_all_*()`,
  `stri_match_all_*()` gained a new argument: `omit_no_match`.
  Setting it to `TRUE` makes these functions compatible with their
  `stringr` equivalents.

* [NEW FEATURE] #118: `stri_wrap()` gained `indent`, `exdent`, `initial`,
  and `prefix` arguments. Moreover, Knuth's dynamic word wrapping algorithm
  now assumes that the cost of printing the last line is zero, see #128.

* [NEW FEATURE] #122: `stri_subset()` gained an `omit_na` argument.

* [NEW FEATURE] `stri_list2matrix()` gained an `n_min` argument.

* [NEW FEATURE] #126: `stri_split()` is now also able to act
  just like `stringr::str_split_fixed()`.

* [NEW FEATURE] #119:  `stri_split_boundaries()` now has
  `n`, `tokens_only`, and `simplify` arguments. Additionally,
  `stri_extract_all_words()` is now equipped with `simplify` arg.

* [NEW FEATURE] #116: `stri_paste()` gained a new argument:
  `ignore_null`. Setting it to `TRUE` makes this function more compatible
  with `paste()`.

* [OTHER] #123: `useDynLib` is used to speed up symbol look-up in
  the compiled dynamic library.

* [BUGFIX] #114: `stri_paste()`: could return result in an incorrect order.

* [BUGFIX]  #94: Run-time errors on Solaris caused by setting
  `-DU_DISABLE_RENAMING=1` - memory allocation errors in, among others,
  the ICU `UnicodeString`. This setting also caused some `ASAN` sanity check
  failures within ICU code.

-------------------------------------------------------------------------------

## 0.3-1 (2014-11-06) **CRAN**

* [IMPORTANT CHANGE] #87: `%>%` overlapped with the pipe operator from
  the `magrittr` package; now each operator like `%>%` has been renamed `%s>%`.

* [IMPORTANT CHANGE] #108: Now the `BreakIterator` (for text boundary analysis)
  may be more easily controlled via `stri_opts_brkiter()` (see options `type`
  and `locale` which aim to replace now-removed `boundary` and `locale`
  parameters to `stri_locate_boundaries()`, `stri_split_boundaries()`,
  `stri_trans_totitle()`, `stri_extract_words()`, and `stri_locate_words()`).

* [NEW FUNCTIONS] #109: `stri_count_boundaries()` and `stri_count_words()`
  count the number of text boundaries in a string.

* [NEW FUNCTIONS] #41: `stri_startswith_*()` and `stri_endswith_*()`
  determine whether a string starts or ends with a given pattern.

* [NEW FEATURE] #102: `stri_replace_all_*()` now all have the `vectorize_all`
  parameter, which defaults to `TRUE` for backward compatibility.

* [NEW FUNCTION] #91: Added `stri_subset_*()` - a convenient and more efficient
  substitute for `str[stri_detect_*(str, ...)]`.

* [NEW FEATURE] #100: `stri_split_fixed()`, `stri_split_charclass()`,
  `stri_split_regex()`, `stri_split_coll()` gained a `tokens_only` parameter,
  which defaults to `FALSE` for backward compatibility.

* [NEW FUNCTION] #105: `stri_list2matrix()` converts lists of atomic vectors
  to character matrices, useful in conjunction with `stri_split()`
  and `stri_extract()`.

* [NEW FEATURE] #107: `stri_split_*()` now allow
  setting an `omit_empty=NA` argument.

* [NEW FEATURE] #106: `stri_split()` and `stri_extract_all()`
  gained a `simplify` argument
  (if `TRUE`, then `stri_list2matrix(..., byrow=TRUE)`
  is called on the resulting list).

* [NEW FUNCTION] #77: `stri_rand_lipsum()` generates
  a (pseudo)random dummy *lorem ipsum* text.

* [NEW FEATURE] #98: `stri_trans_totitle()` gained a `opts_brkiter`
  parameter; it indicates which ICU `BreakIterator` should be used when
  case mapping.

* [NEW FEATURE] `stri_wrap()` gained a new parameter: `normalize`.

* [BUGFIX] #86: `stri_*_fixed()`, `stri_*_coll()`, and `stri_*_regex()` could
  give incorrect results if one of search strings were of length 0.

* [BUGFIX] #99: `stri_replace_all()` did not use the `replacement` arg.

* [BUGFIX] #112: Some of the objects were not PROTECTed from
  garbage collection - this could have led to spontaneous SEGFAULTS.

* [BUGFIX] Some collator's options were not passed correctly to ICU services.

* [BUGFIX] Memory leaks as detected by
  `valgrind --tool=memcheck --leak-check=full` have been removed.

* [DOCUMENTATION] Significant extensions/clean ups in the stringi manual.

-------------------------------------------------------------------------------

## 0.2-5 (2014-05-16) **CRAN**

* ~~icudt-dependent examples are no longer run if `icudt` is not available.~~

-------------------------------------------------------------------------------

## 0.2-4 (2014-05-15) **CRAN**

* [BUGFIX] Fixed issues with loading of misaligned addresses
  in `stri_*_fixed()`.

-------------------------------------------------------------------------------

## 0.2-3 (2014-05-14) **CRAN**

* [IMPORTANT CHANGE] `stri_cmp*()` now do not allow for passing
  `opts_collator=NA`. From now on, `stri_cmp_eq()`, `stri_cmp_neq()`,
  and the new operators `%===%`, `%!==%`, `%stri===%`, and `%stri!==%`
  are locale-independent operations, which base on code point comparisons.
  New functions `stri_cmp_equiv()` and `stri_cmp_nequiv()`
  (and from now on also `%==%`, `%!=%`, `%stri==%`, and `%stri!=%`)
  test for canonical equivalence.

* [IMPORTANT CHANGE] `stri_*_fixed()` search functions now perform
  a locale-independent exact (byte-wise, of course after conversion to UTF-8)
  pattern search. All the `Collator`-based, locale-dependent search routines
  are now available via `stri_*_coll()`. The reason behind this is that
  ICU's `USearch` has currently very poor performance. What is more,
  in many search tasks exact pattern matching is sufficient anyway.

* [GENERAL] `stri_*_fixed` now use a tweaked Knuth-Morris-Pratt search
  algorithm which improves the search performance drastically.

* [IMPORTANT CHANGE] `stri_enc_nf*()` and `stri_enc_isnf*()` function families
  have been renamed `stri_trans_nf*()` and `stri_trans_isnf*()`,
  respectively -- they deal with text transforming,
  and not with character encoding. Note that all of these may
  be performed by ICU's `Transliterator` too (see below).

* [NEW FUNCTION] `stri_trans_general()` and `stri_trans_list()` give access
  to ICU's `Transliterator`: they may be used to perform some generic
  text transforms, like Unicode normalization, case folding, etc.

* [NEW FUNCTION `stri_split_boundaries()` uses ICU's `BreakIterator`
  to split strings at specific text boundaries. Moreover,
  `stri_locate_boundaries()` indicates positions of these boundaries.

* [NEW FUNCTION] `stri_extract_words()` uses ICU's `BreakIterator` to
  extract all words from a text. Additionally, `stri_locate_words()`
  locates start and end positions of words in a text.

* [NEW FUNCTION] `stri_pad()`, `stri_pad_left()`, `stri_pad_right()`,
  and `stri_pad_both()` pad a string with a specific code point.

* [NEW FUNCTION] `stri_wrap()` breaks paragraphs of text into lines.
  Two algorithms (greedy and minimal raggedness) are available.

* [IMPORTANT CHANGE] `stri_*_charclass()` search functions now
  rely solely on ICU's `UnicodeSet` patterns. All the previously accepted
  charclass identifiers became invalid. However, new patterns
  should now be more familiar to the users (they are regex-like).
  Moreover, we observe a very nice performance gain.

* [IMPORTANT CHANGE] `stri_sort()` now does not include `NA`s
  in output vectors by default, for compatibility with `sort()`.
  Moreover, currently none of the input vector's attributes are preserved.

* [NEW FUNCTION] `stri_unique()` extracts unique elements from
  a character vector.

* [NEW FUNCTIONS] `stri_duplicated()` and `stri_duplicated_any()`
  determine duplicate elements in a character vector.

* [NEW FUNCTION] `stri_replace_na()` replaces `NA`s in a character vector
  with a given string, useful for emulating, e.g., R's `paste()` behavior.

* [NEW FUNCTION] `stri_rand_shuffle()` generates a random permutation
  of code points in a string.

* [NEW FUNCTION] `stri_rand_strings()` generates random strings.

* [NEW FUNCTIONS] New functions and binary operators for string comparison:
  `stri_cmp_eq()`, `stri_cmp_neq()`, `stri_cmp_lt()`, `stri_cmp_le()`,
  `stri_cmp_gt()`, `stri_cmp_ge()`, `%==%`, `%!=%`, `%<%`, `%<=%`,
  `%>%`, `%>=%`.

* [NEW FUNCTION] `stri_enc_mark()` reads declared encodings of character
  strings as seen by stringi.

* [NEW FUNCTION] `stri_enc_tonative(str)` is an alias to
  `stri_encode(str, NULL, NULL)`.

* [NEW FEATURE] `stri_order()` and `stri_sort()` now have an additional
  argument `na_last` (defaults to `TRUE` and `NA`, respectively).

* [NEW FEATURE] `stri_replace_all_charclass()`, `stri_extract_all_charclass()`,
  and `stri_locate_all_charclass()` now have a new argument, `merge`
  (defaults to `FALSE` for backward-compatibility). It may be used
  to, e.g., replace sequences of white spaces with a single space.

* [NEW FEATURE] `stri_enc_toutf8()` now has a new `validate` arg (defaults
  to `FALSE` for backward-compatibility). It may be used in a (rare) case
  where a user wants to fix an invalid UTF-8 byte sequence.
  `stri_length()` (among others) now detects invalid UTF-8 byte sequences.

* [NEW FEATURE] All binary operators `%???%` now also have aliases `%stri???%`.

* [GENERAL] Performance improvements in `StriContainerUTF8`
  and `StriContainerUTF16` (they affect most other functions).

* [GENERAL] Significant performance improvements in `stri_join()`,
  `stri_flatten()`, `stri_cmp()`, `stri_trans_to*()`, and others.

* [GENERAL] Added 3rd mirror site for our `icudt` binary distribution.

* `U_MISSING_RESOURCE_ERROR` message in `StriException` now suggests
  calling `stri_install_check()`.

* [BUGFIX] UTF-8 BOMs are now silently removed from input strings.

* [BUGFIX] No more attempts to re-encode UTF-8 encoded strings
  if native encoding is UTF-8 in `StriContainerUTF8`.

* [BUGFIX] Possible memory leaks when throwing errors via `Rf_error()`.

* [BUGFIX] `stri_order()` and `stri_cmp()` could return incorrect results
  for `opts_collator=NA`.

* [BUGFIX] `stri_sort()` did not guarantee to return strings in UTF-8.

-------------------------------------------------------------------------------

## 0.1-25 (2014-03-12) **CRAN**

* LICENSE tweaks.

* Initial CRAN release.

-------------------------------------------------------------------------------

## 0.1-24 (2014-03-11) **devel**

* Fixed bugs detected with `ASAN` and `UBSAN`,
  e.g., fixed `CharClass::gcmask` type (`enum` -> `uint32_t`)
  (reported by `UBSAN`).

* Fixed array over-runs detected with `valgrind` in `string8.h`.

* Fixed unitialized class fields in `StriContainerUTF8`
  (reported by `valgrind`).

-------------------------------------------------------------------------------

## 0.1-23 (2014-03-11) **devel**

* License changed to BSD-3-clause, COPYRIGHTS updated.

* `icudt` is not shipped with stringi anymore;
  it is now downloaded in `install.libs.R` from one of our servers.

* New functions: `stri_install_check()`, `stri_install_icudt()`.

-------------------------------------------------------------------------------

## 0.1-22 (2014-02-20) **devel**

* System ICU is used on systems which do have one (version >= 50 needed).
  ICU is autodetected with `pkg-config` in `./configure`.
  Pass `'--disable-pkg-config'` to `./configure` to force building
  ICU from sources.

* `icudt52b` (custom subset) is now shipped with stringi
  (for big-endian, ASCII systems).

-------------------------------------------------------------------------------

## 0.1-21 (2014-02-19) **devel**

* Fixed some Solaris-related issues while preparing stringi
  for CRAN submission.

-------------------------------------------------------------------------------

## 0.1-20 (2014-02-17) **devel**

* ICU4C 52.1 sources included (common, i18n, stubdata + icu52dt.dat
  loaded dynamically). Compilation via Makevars.

* stringi now does not depend on any external libraries.

-------------------------------------------------------------------------------

## 0.1-11 (2013-11-16) **devel**

* ICU4C is now statically linked on Windows.

* First OS X binary build.

* The package is being intensively tested by our students @ FMIS WUT.

-------------------------------------------------------------------------------

## 0.1-10 (2013-11-13) **devel**

* Using `pkg-config` via `./configure` to look for ICU4C libs.

-------------------------------------------------------------------------------

## 0.1-6 (2013-07-05) **devel**

* First Windows binary build.

* Compilation passed on Oracle Sun Studio compiler collection.

* By now we have implemented most of the functionality
  scheduled for milestone 0.1.

-------------------------------------------------------------------------------

## 0.1-1 (2013-01-05) **devel**

* The stringi project has been established on GitHub.

-------------------------------------------------------------------------------
